End of this story but the beginning of many more

While Summer Immersion term is over, my project most definitely is not. Over the past few weeks I’ve been spending less and less time in the OR and the clinic and more time behind a computer learning statistical methods and doing statistical analysis. My project has been to use a database created by medical research assistants to determine if there is a correlation between the rate of complications after radical cystectomy and the type of cystectomy being performed (robotic vs. open). The crazy thing is that in all my weeks at Weill I had yet to see an open cystectomy. It seems that Dr. Scherr is somewhat defined for his ability and proficiency with robotic cystectomies. Just yesterday I had my first opportunity to see an open cystectomy, so I popped into the OR to see what my analysis was really evaluating. The surgery definitely seemed more difficult without the magnification of the robotic camera, but the reality is that many surgeons still prefer to perform this surgery open because they are more proficient behind the table rather than at a robotic console. The specific case Dr. Scherr was performing was an open cystectomy because the patient had had a partial nephrectomy before and they knew there would be scar tissue to deal with that they were unaccustomed to with the robot.

I say that my research project is definitely not over for a couple of reasons. First, I will continue to analyze and tweak our model over the next few days to see if I can improve the model fit. We had to use multinomial logistic regression to analyze the data because we are looking at a binary outcome (complication or no complication). Additionally many of our predictor values are ordinal or nominal rather than scalar. The five variables we choose to evaluate (we being a few residents and I) are body mass index (BMI), age, Charlson score, ASA score (American Society of Anesthesiologists score) and the type of cystectomy (robotic or open). I first looked for a basic correlation between the type of cystectomy and occurrence of complications using crosstabulation and Pearson chi-squared tests. This showed that there is a significant correlation between the two, but we needed to ensure that was not just an artifact of other factors. For example we needed to prove that it is not just the younger, leaner, healthier patients that are undergoing robotic cystectomies. To show this more rigorously I needed to use multivariate regression but with these nominal and categorical variables. In the end I think I developed accurate models, but only more time and more critical evaluation by the residents will tell. Secondly this project is far from over because our analysis is limited by the fact that we only have around 200 patients. At first I thought this was more than sufficient, but as I continued to do my analysis and needed to categorize these cases the sub-grouping became ever smaller making statistical analysis very difficult. So this evaluation will just be the foundation that they can build upon in years to come as they continue to have a more robust database of cases.

Finally I just want to remark on the miracle of life. Last Friday Jen and I had a wonderful opportunity to observe a C-section. Not only were the patients gracious at having additional people in the room but the surgeon was also keen to teach us. Before we ever entered the OR he had us read-up on why this patient was having a C-section. This woman had a bicornuate bicollis uterus (which is to say she had a septum in her uterus dividing it in two). A C-section was required and might need to be performed along the length of the uterus rather than at the base because her two uteri are narrower than a standard woman’s uterus. In this case though, they were able to get the baby out of the base of pregnant uterus and could even show us the amazing capability of the uterus to expand with a baby since this woman had one pregnant and one non-pregnant uterus. So not only had we walked in to see a C-section, but we also walked in on a high risk pregnancy that had come to full term with a healthy baby. Additionally this was the first child for these parents and they didn’t know the baby’s sex, so it was a very exciting OR!

Yeah!! The Last Week of Summer Immersion

Wrapping up the data I have collected until now and catching the last chance to visit the OR I haven't been before, these two things are basically what I have been doing in the last week. Even though I knew that I won't be able to finish the great plan of website within six weeks a long time ago, even though I knew that there are numerous small miracles and drama happening somewhere in this hospital I wouldn't be able to learn, even though I still have tons of questions and ideas in my mind about the PC measurement, I had to face to fact that: the last week of this summer immersion program is coming to an end.

In retrospect, six weeks is really too short for me to get enough insight into the hospital. This morning when I watched the whole process of C-section for the first time and maybe the last time in my life, the strong contradiction between the bloody scene and the super happy expression on the face of the mother was still a great shock to me. As an undergraduate in biology, I would never be be touched by a bloody experiment and hardly moved by an affecting drama. Because of that, I underestimated the power of the inevitable combination of the two in hospital before I could realize it. Though for many times I reminded myself not be too involved in personal emotion about one single case, I know it is actually very hard. How could one find a simple righteous principle in the mergence area of natural and social science? How could the hybrid of research institution and social facilities be easily judged on right and wrong?

Knowing this, I am very happy that this program could offer me this chance to have a little touch to the knowledge of this super complicated system during the short six weeks under such circumstances. Perhaps many years later, most of the medical terms I learned at this moment would be gradually erased from my memory. Nevertheless, there are definitely some scenes, some people and some words I once came across in this summer would remind me from time to time many different aspects I used to neglect when studying healthcare in the lab. They will also remind me what kind of things I should pay attention to besides the improvement of technology in my career as a bioengineer.

Knowing this, I am not regretful that I have only been here for six weeks. Actually, on the other hand, I found myself can be helpful to someone in hospital right in the last week. When the assistant of doctor came over to me in panic asking about some net questions, when the medical student also came over to ask me some math conceptions in references, I finally felt that I little "nobody" BME PhD could also do "something" here!

All done

Going through 200 patient charts to extract data was very energy consuming. Since all my patients look normal, I had no reasons to take a picture of them to post on the blog, so I decided to post pictures of me with food instead since it's restaurant week.

After data analysis, I found some similarities and differences. For instance, patients who have severe symptoms with minimal Jak2 allele burden tend to have a higher time between first drug treatment and diagnosis. Patients with high Jak2 tends to be about about 10 years younger than patients with low Jak2, etc. All data are being submitted to the statistics department for verification.

John Thomas will have to do

In the last two weeks, I’ve spent most of my time in the clinic and OR. I saw several interesting and pretty nauseating cases. Let’s start in the clinic.

There was a patient with an infected hematoma on his leg. It was pretty disgusting to look at immediately after he took off his bandages. Basically there was a putrid, fleshy black spot on his shin. Dr. Vouyouka had to debride the wound so that it would heal properly, which consisted of surgically removing the dead tissue and irrigating the area. From the patient’s groans and screams—no, he wasn’t put under—the debridement seemed to be an excruciating procedure. Afterwards, gauze was packed into the wound beneath the dermal layer. Moral of the story: take care of your wounds!

In the OR, I saw a thrombectomy that was performed on a woman with a leaky brachial artery in her right arm that resulted in a nasty hematoma. Truthfully, the doctors didn’t really know why her artery was leaky but went and opened her up anyway. I guess they were planning on fixing the artery but found, or maybe even created, a thrombus.

The bloodiest case I saw was a below-the-knee amputation. This was also the most straightforward case I observed during my summer here so far. As you can imagine, Dr. Vouyouka basically cut through all the layers to get to the bone. The bone had to be sawed and any arteries that were cut were tied up. They cut the leg in such a way that the calf muscle was used as a flap to cover everything.

Lastly, I saw a carotid endarterectomy (CEA), which involves the removal of an atherosclerotic plaque from a carotid artery. There are certain complications with this procedure, such as ensuring blood supply to the brain, which is done most often by using a shunt to deliver blood and electroencephalography (EEG) to monitor the brain. To diagnose a stenosed carotid, magnetic resonance angiogram (MRA) or ultrasound is used to determine how much occlusion has developed in the blood vessel.

I wanted to mention CEA last because my summer research project is directly related to this procedure. I am analyzing clinical data and trying to make sense of the differences between men and women in the events leading up to and after their CEA. Some parameters included in my data-mining include: presence of hypertension, high cholesterol, coronary artery bypass graft (CABG), transient ischemic attacks (TIA), cerebrovascular accidents (CVA/strokes), myocardial infarctions (MI), and restenosis.

It looks like I should be able to finish my data collection and analyze everything by the end of this term. I’m also excited about going back to Ithaca and working in the new BME building. One thing I’ll miss about NYC is the Michelin-rated restaurants I’ve been lucky enough to eat at. After eating the hanger steak at JoJo, I can die happy.

Measurement, New Ideas and More Measurement

Last week I put more effort on one of Dr. Prince's new project: comparing the change of portal vein flow before and after meal in normal people and cirrhotic patients. Dr. Prince, me and other two medical students are working on the the pre-experiment part right now. Tons of problems with new ideas poped out, which made this week compact and intense.

It has been a long time that doctors found food intake can cause significant increase of portal blood flow, however, fibrous scar and regenerative nodules generated in cirrhosis can severely affect the liver reserve of this flow change. Studies on the comparison of this flow change between normal volunteers and cirrhotic patients by Doppler measurements started about decades ago. But because of the poor accuracy of Doppler in flow measurements, all the previous studies have many discrepancies, rendering this mecomparison not feasible in the diagnosis for early cirrhosis.

On the other hand, MRI can also do the flow measurement using PC (phase contrast) sequence. So Dr. Prince came up with the idea that whether MR can be used to improve the measurement of the portal flow change. Last week, we first tried out this measurement on him before and after meal. Surprisingly, after several repeated scanning, we found the measurement of the same portal flow can be very different in PC. What may cause the measurement error in PC? If we found them out, is it possible that we can get much better measurement of portal flow using MR?

Aiming for discorvering a better non-invasive diagnosis for early cirrhosis, we thought about many parameters that can be modified to achieve the improvement: resolution, SNR, and tricks to make the contour of portal vein, etc. To test these ideas, we need a proper phantom of human portal vein first. Then we came up with the "U-shape tubing phantom" idea. We connected a tubing bended into U shape to the injector of contrast agent and this could work as a nice continous flow phantom mimicing portal vein within 1 minute. Comparing the flow measurement obtained from both "in" and "out" profile of this tubing, we could get an idea about how sensible the scanning method or how accurate the measurement is with the known flow rate in the phantom.

After a whole week fighting with air bubbles, water leakage and all kinds of problems, we have finally got some very useful preliminary data. I am excited about this and will continue to do more measurement this week after analysing the current data thoroughly. I will keep you guys posted on this~

Projects and Projections

Now that the term is winding down I'm beginning to feel the crunch to finish my project. It will require a fair amount of effort, but I think it can be completed with time to spare. The parameters of my project are pretty simple. Dr. Schwartz is very interested in epilepsy, and specifically methods for treating cases of epilepsy that are refractory to drug therapy. Often in these cases, there is one localized portion of the brain responsible for the epileptic activity. These patients can opt to have this portion of the brain removed (which is where Dr. Schwartz comes into play), thereby eliminating the seizures. But removing a part of somebody's brain is obviously costly, dangerous, and potentially debilitating. Is it possible to do any better? Well maybe. However, first more knowledge needs to be attained about the way depolarization waves spread in the brain.

A medical student working in Dr. Schwartz's lab took massive amounts of data over the course of two years, stimulating rat brains at various frequencies and analyzing the hemodynamic response. One of the things Dr. Schwartz has asked that I do during my stay at Weill is analyze the data in a meaningful way, so that blood flow response can be correlated with the stimulus. As always in biological, medical, and engineering fields, this task is a little more convoluted than it superficially appears. Firstly, it requires sorting through volumes of data to determine which is "good" and which is "bad." Not to be confused with desirable versus undesirable data, there is actually an issue of noise corrupting some of the data to the point that it is totally unusable. In general, the data can be viewed by the equation: data=gain*truth + bias + noise. I'm trying to cleverly extract the truth from this equation so it can be analyzed. In a perfect world, gain would be 1, and bias and noise would be 0, but I don't expect to be so lucky. Fortunately there is a ton of information on estimation and detection methods, which I can use to hopefully solve this problem.

Decisions

As my summer gets more and more immersed I have begun to really enjoy visiting other surgeon’s ORs. I especially enjoy the mobility that I have been allowed by the plastic surgery department. Over the course of the summer I have seen quite a few breast reconstruction cases because of this mobility. It is quite fascinating to see the different techniques each doctor uses and to see which techniques their residents and fellows have started picking up as they learn. I bring this up because last week I was able to stand in on a surgery with a different doctor than my clinician and see a surgery I have been curious about all summer. I’ve seen quite a few skin grafts and flaps, as well as breast reconstructions post mastectomy with tissue expanders, but it is the TRAM flap surgery that I was really intrigued by.

The TRAM flap, or transverse rectus abdominis myocutaneous flap, is a fairly ingenious way to aesthetically correct a traumatic surgery with a patient’s own tissue. I have had quite a bit of contact with pre-op and post-op mastectomy patients during clinic hours and have heard how difficult the decision is for the method of reconstruction. These patients basically have two choices, the choice of using a tissue expander followed by a permanent implant (silicone or saline, which unto itself is a difficult decision) or the TRAM flap procedure. Both require nipple reconstruction afterward (though a few doctors are now working on nipple saving mastectomies), but the consequences of each are hard to decide between. An implant of course is a synthetic material inside your body, but recovery time is much quicker. The TRAM flap involves taking a large portion of abdominal skin, tissue, and part of the rectus abdominis muscles (in lay terms, your abs), and fashioning a new breast out of that in place of the removed one. This is a much longer surgery, a longer recovery, a lifelong weakening of your abdominal muscles with the increased risk of a hernia and the flap does have the possibility of dying, which in term would lead right back to a tissue expander/implant surgery. Though with the TRAM flap surgery you are replacing your lost breast with your own transplanted tissue and you get a tummy tuck out of the entire process. Seriously not a decision I would want to make, ever.

As I mentioned bore, the patient was not one of Dr. Spector’s patients, but the other surgeon was quite accommodating to let me stay for the 6+ hour operation and attempted to ensure I had a view/knew what was going on. The procedure itself was not a free flap procedure, so in this case the rectus muscle wasn’t cut completely off from the blood supply before being sewn to the tissue above for relocation. This complex, known as the pedicle, was then pushed through a tunnel under the skin made from the abdomen diagonally to the affected side of the chest and sewn into place. After discussing the procedure with Dr. Spector, I found that his preference is actually to perform this as a free flap and actually remove the entire muscle and microsurgically re-establish the blood flow that was feeding the flap. Like I mentioned before, every doctor has their own established way to tackle the same problem. This is why it is important to speak to a few doctors when electing to undergo any surgery. Not every surgeon is the right fit for a patient and the ability to hear new ideas and takes on a situation is important when making an informed choice. Regardless, the surgery was immensely fascinating and seeing this shapeless mass of adipose tissue and skin suddenly come together to form a new breast was astounding. I think it is safe to say I will always be constantly amazed at what doctors have pioneered in surgery.

Putting together the Puzzle Pieces

Recently I’ve had the opportunity to widen my horizon further beyond the Urology department. I’ve done rounds with Dr. Cooke in the ICU and followed Dr. Tagawa in the Medical Oncology clinic. Although both of these areas are very different from my general experiences in Urology rounds and clinic, at the same time, they are all related.

In the ICU, I experienced two different types of care. Many patients had come in the night before or the day before with an acute symptom (ie nausea, disorientation, shortness of breath). These patients were quickly being moved through diagnosis, treatment and recovery either in the ICU or in another unit of the hospital. Other patients though had more devastating diagnoses which left them in the ICU for a lengthier period of time. Many of these cases were due to the severity of disease or the patients’ inability to breath on their own.

In the Oncology clinic, we visited with patients who had metastasized cancers generally from the bladder, prostate or kidney. Additionally, many of these patients had been through either a surgical procedure to treat their primary cancer site or had undergone chemo or radiation. In general, the patients were visiting Dr. Tagawa in order to alter chemo, enroll in a clinical trial, start hormonal therapy or get general consultation as to what to do next. I was amazed by the variety of patients he saw and how thorough he was with each patient. Each case definitely required customized care and Dr. Tagawa was able to provide not only the standard options for care, but also the numerous clinical trails that were going on under a variety of clinicians.

So now to putting all the puzzle pieces together… My research project with Dr. Scherr is analyzing data from radical robotic cystectomies. Included in the database is detailed information for each patient which allows us to analyze the outcomes with regards to prior surgeries or treatments and complications that occur afterwards. Having looked at this data for a while now, visiting the ICU brought new life to the complications of re-admittance due to sepsis or pneumonia. As well, visiting the Oncology Clinic gave me an idea of what patients go through if their cancer returns. I had visited patients after their cystectomy in Dr. Scherr’s clinic and often the difficulties are with incontinence at night, but the patients in the Oncology Clinic with recurrence deal with many more challenges as they weigh their options for further treatment.

Finally, I’d just like to make a comment about the many roles I’ve seen Dr. Scherr play over the past few weeks. He is both a physician administering personalized care, a surgeon with technical skills, a researcher always asking questions and even an entrepreneur looking for new developments to change the way treatment in administered. I’ve been amazed to see him put on these different “hats” and even more astonished to see just how well each one fits.

I like mice

Other than going to clinics for 5 hours, I spent my week in the library in front of my laptop. My research project is on polycythemia vera patients who have mild symptoms when they have high JAK2 allelle burden, or severe symptoms with minimal JAK2 positive ratio. Normally, patients with increasing ratio of JAK2 positive burden have increasing phenotypes of the disease. For some reasons, these people have opposite output than what's expected. Several problems I run into during my statistical analysis include: incomplete/unorganized data (missing from different doctors, etc.), very small sample of patients, and not being able to rule out what causes what exclusively since we can't just test things on human patients. I'm not so sure if a publication is going to come out of this, but my fingers are crossed.

Week 5: Rollin'

Finally back to a regular full week's schedule, unobstructed by the national holidays nor other commitments! The last two weeks have been shortened one way or another, so it's great to be immersed for a full week again!

I spent most of the time bouncing around between Floors 0, 2, and 4 of the Starr Building this week, and reinforcing what I have learned about cardiology and different kinds of imaging so far in the program. Got to ask the fellows, nurses, and techs in each department tons of questions, as well as getting a lot more interesting references and resources to read. It was also great to see the end of the tunnel for my immersion project, for which I now have a realistic timeline to complete the study and possibly a paper or an abstract.

This week, I'll write a little bit more about the software that's used in my project, the LVMetric Segmentor, which was developed at WCMC to speed up the segmentation process of cardiac images. Image segmentation provides a lot of important information, such as the chamber volume, blood mass, etc. which can be used as an indicator for certain diseases. In the past, doctors spend an awfully long time on each image case to segment myocardium from the chambers, while taking into account the papillary muscle mass, etc. For each patient's image, it can take anywhere from 4 to 10 minutes for an experienced doctor like Jonathan to segment the image profiles at the systolic and diastolic cardiac phases. LVMetric, on the other hand is very efficient, as it automates this segmentation process using some nifty image transforms and segmentation algorithms, and does it for all 25 or so different cardiac phases; in a matter of few seconds!

In addition to speeding up the process for doctors, the software can get data point at almost every cardiac phase; this allows us to study the temporal aspects of the chamber volume, etc. at each moment in the cardiac phase. We've recently added a new function to the program, so that it can output a decent amount of data from different cases that we examine. The remainder of my project starting Monday will be to organize, process, and analyze the volume curve for a number of these cases (Jonathan said it would be ~20 or so).

From this study, we are hoping to identify a quantitative indicator of certain physiological defects by analyzing quantitative data that I will work with. So it will be time to hit my Statistics textbooks hiding somewhere in my room next week (where are they?!). I'm really looking forward to wrapping up my project.

Finally, I got to follow Dr. Frayer on the rounds in the NICU this morning; I really must resonate Shawn and everybody else's earlier comments: man those babies are cute!

Interesting experience this week

It is never a rare case to see some patients with breast cancer in radiology department. During the past weeks, I have written about two cases with breast cancer or breast cancer history in my post. This week, an especially interesting case came in, and gave me some brand-new insights into healthcare.

This is a 44-year-old breast cancer patient coming in with a bright blue scarf wrapped around head, which is undergoing hair loss due to the radiation therapy. I talked with her for a while she was waiting for the scan. Different from some other patients, I found her very cheerful throughout the short chat. Rattling super happily and proudly on her twins, she almost made me forget she was actually a cancer patient. The surprising thing happened at the time when I found out she actaully came to do an abdomen scan rather than a chest scan. Was this for checking the possible metastasis? I thought this way at first. But things just surprised me more when I gradually noticed the technicians paid more attention to some abdominal blood vessels. At last the most elucidating yet surprising thing came when I was told she was actually doing this scan for the susceptabilty test of a breast reconstruction surgery.

I know this is still confusing so let me explain more. Obviously this optimistic lady had not underwent a surgery to take out the breast cancer yet. She was doing the radiation therapy right now to suppress the cancer cells, so that they won't metastasize so easily post surgery. At the same time, she was also worried that she won't look so good after the excision of breast and DIEP Flap Breast Reconstruction technology came at the right time. Her surgeons planned to carry out two surgeries - mastectomy and breast reconstruction - on her at the same time, but before that, they need to make sure that her perforator vessels are still intact so that they are able to function as the internal mammary blood vessels later. She was very happy to learn the good news that day: her perforator vessels look super good even after the incision in C-section many years ago.

For me, this story totally refreshed my idea about the role of surgery in healthcare. In my old memory, surgery is always related with pain, wound and scar; surgery happens when medicine fails. However, this time just imagining nowadays patients can actually choose to combine resection with orthopaedics, I am totally overwhelmed. You can get cure and beauty at the same time - one stone two birds - isn't it fantastic?

Of course I understand that this technology must also be very controversial. Just like people would even argue whether this is worthy and safe to create an artificial beauty through orthopaedics, DIEP Flap Breast Reconstruction on a cancer patient is also risky. Recovery from two surgeries is definitely slower, not to mention the underlying risk to keep some breast tissues near lesions for better reconstruction. The fact is, ethic problems always come with healthcare. Nevertheless, the hope for benefiting more from medical technology never dies. Medical care is not all about elongating one's life. It also helps improving the quality of life, and the way we look at life and ourselves. There is nothing more important than that patients find health care help their lives and be happy about it. And I think the impressing part of this case just lies in that it teaches me the function of healthcare CAN be not only for physical well-being, but also spiritual welfare.

New Experiences

Last week I got to see deep brain stimulation surgery. I wanted to see as much as possible because I am supposed to be implanting DBS electrodes in rats for my thesis. Of course I tried so hard to see everything that I kept touching the blue sterile surface. The guy got kind of annoyed with me and I felt stupid and useless. My clinician also was telling me that I was getting too close. It is a very serious surgery, so I understood that I need to stay back to some extent. Nonetheless, it was fascinating. They used a lot of trial and error to find the right position and voltage of the electrode to maximize benefit for the treatment of Parkinsonian symptoms without interfering with motor control. They kept asking the guy to speak the days of the week. Sometimes it was muffled, sometimes it wasn't. I guess it varied depending on the positioning of the electrode. They also told him to flex his feet and open/close his hand. The surgery lasted for several hours.

The next day I saw three plastic surgeries. These surgeons were sooo much less serious. They played music, joked around, and the head surgeon played peek-a-boo behind the door. In the first two surgeries there was a lot of manipulation of the skin. In one, the skin would be stretched over time, then excess skin would be used to replace scar tissue. In the other surgery, the woman needed a skin graft. I could see all the exposed muscle that they were covering up. She also had the biggest blister on her heel that I had ever seen. It looked like a giant diabetic blister or something.

Today I saw open heart surgery. They are right, it is intense. They bypassed the heart and lungs so that they could treat an aortic valve inefficiency. The blood went to a machine that acted as a heart. The resident said they would take a blood vessel from the leg and use it to replace one of the aortic vessels. It did not see the whole thing because I had other things to do.

I really want to learn as much about stereotactic surgical techniques from my clinician as possible, specifically on dissecting rats. He had me hook up with a woman in his lab who plans on doing stereotactic surgery. She said she had never done stereotactic surgery either. Not too encouraging. On the other hand, Yi stated clearly that this work is not meant to be for our theses.

I continued to work on the research protocol that Dr.Frayer says is junk. I was too lazy to change what I was doing and figured that at least I am learning a lot about neuroanatomy, something that is important to me in pursuing a neural engineering career. Now that I have learned about the neuroanatomy of drug addiction, I think about the reward circuit when I pop in snack foods and go out for a run. I have finished writing about the rationale now, so I don't know what he will have me do next.

Week 4: Mathematical Modeling and Montreal

So I missed a few days of the Immersion program teaching for a Math Camp in Montreal. For the summer camp, I was preparing a fun talk that discusses some ways that math can help in the clinical settings. While preparing this talk, I figured there was no better way than asking the immersion clinicians for ideas that I can talk about. So here it is:

As engineers, we often use mathematics as a set of tools for solving problems. From fluid dynamic models of blood flow, to certain clinical data analysis, there are numerous ways to use math in clinical settings. One topic that caught my attention, and fascinated me was the problem of how organ transplants are optimized at the local, regional, and national levels. There is an increasing trend of government funding for an efficient network called the Organ Procurement and Transplantation Network (OPTN). I've seen an analogous problem, (about the renal transplant network) last year in a mathematical modeling contest, and thought this would be a great problem to think about and ask around.
The topic of establishing an effective network is a difficult one, because of the many factors that must be incorporated in developing this model. As there are more organs sought after than there are available, there would usually be a significant waiting list for patients who need a new organ. One could try making a population dynamics model (using a system of ordinary differential equations) to get a holistic idea of how the waiting list behaves over the long course, but many indications suggest that we are all moving more towards larger and larger waiting lists in the future for almost all organs. Supply simply does not meet the demand.

One novel approach for resolving this situation was looking at donor-patient pairs. It is often true that exists a donor who is more than willing to donate an organ to a specific patient (which made sense in the case of a kidney), but the donor's kidneys are not compatible with the patient. If this is the case, it would make sense to establish a two-way exchange, so the two donors would trade their kidneys.

As a mathematician, one would like to generalize into establishing an n-way exchange, and finding a mathematically elegant solution that solves this optimization problem. However, from a clinical perspective, there are additional factors that need to be considered before we consider a similar exchange. First, suppose we establish an n-way exchange, but the chain breaks (eg. extraction fails) at some point. If this happens, what are the repercussions of such failure to the whole chain? One patient will not receive a sought after kidney due to the failure, while its donor, whose kidney is somewhat like a bargaining chip for acquiring his or her patient's new kidney, may break off; would this result in the entire chain of surgeries to fall apart? If so, will that mean that the all n transplants must happen simultaneously? Second is the feasibility of such cyclic surgeries; after all, these n-way exchanges require a lot of clinical manpower. Do most facilities have such capabilities? While it may be possible to model these intricacies using mathematics, it still won't address all the questions that clinicians may have.

Through summer immersion, I've learned that to address these problems properly, it would require more than mathematical problem-solvers developing models; a collaboration with clinical experts who work hands-on with these issues is a must. It is interesting to see where these considerations may lead to: NYP-Columbia Hospital was successful in having a 3-way exchange for the renal transplant recently in 2004, and this was a huge step forward.

Time

Well, time is slipping by so quickly I can hardly believe the summer is almost over. As unfortunate as it is that the final weeks of the program approach, the passing time does afford one huge benefit - human interaction. I have hit the point in my summer that a large number of repeat patients of Dr. Spector recognize me and expect my presence. During clinic hours we see a plethora of pre-op, post-op, and consult patients and, since I’m basically glued to Dr. Spector, interact with all of these people.

After hanging around enough during clinic I get to experience a more personal connection and understanding of each case that is presented. It is all well and good to pop into a surgery because the case is interesting or it is a procedure you haven’t seen before, but I really enjoy taking in the big picture. Going into an OR with a patient whom I have met, talked to, and begun to understand their mindset and choice for undergoing a particular type of surgery brings the experience to a whole new level. It is also incredibly gratifying to visit the patient while they recover in the hospital and then follow them as they come in for subsequent post-op visits. It still amuses me that some patients a day after surgery insist on asking how I am doing when they are the ones bandaged up in a hospital bed. I suppose this whole circle of care is what medicine is truly about and as a biomedical engineer I need to try not to forget to live up to the word medical in my title.

Of course I also so have some amazing surgical stories as well. You wouldn’t think I would leave you without the possibility of being grossed out or astonished by what I’ve seen, would you? So here’s what I’ll leave you with this week: We had a patient that needed exploratory wrist surgery to assess and repair the damage done when a circular saw cut their arm. After increasing the length of the wound, the surgical team found that the patient had nicked their tendon and severed one of their median nerve which supplies sensation to the hand. After repairing the tendon, Dr. Spector decided that to fix the nerve it would be best to make a bridge to connect the two damaged ends and not try to force the two ends together under too much tension. So of course the only logical thing to do was obviously take a 2 cm segment of the patient’s vein, clean it, and then sew this graft to join the ends. Again, who thinks of these things?!?! Apparently for nerve damage repair one can use vein grafts for gaps up to 2 cm and get fairly good results. I tell you, medicine is a kooky place.

Pediatrics and Medical Technologies

I spent most of my mornings this week rounding in the Pediatric ICU (PICU). It was a very interesting experience, having spent a couple of weeks in the neonatal ICU. In the neonatal ICU, the most common issues were nutrition/growth, respiratory distress, and cardiac problems. The cases in the PICU were a lot more varied and more complex. In one of the cases, a child was admitted for fever with irritability and inconsolable crying. But because the patient had such an extensive medical history (despite being so young), which included a repaired paraesophageal hiatus hernia , Lennox-Gastaut syndrome, and myoclonic seizures, it was difficult to diagnose whether the crying was a result of pain from the surgery or a neurological issues. It took an entire week, and consults from multiple departments and hospitals, to rectify the problem at admission. By the end of the week, the child was dramatically better and was due for discharge. It was really satisfying to experience the entire diagnosis process of a complex case that led to resolution of the problem.

In the past month, I've made some interesting observations regarding medical technologies in the hospital too through my time on the floor, and at various conferences. These are key considerations for any technology to be developed for patient care.

1) Mobility: There are so many patient transfers that go on in the hospital everyday - to and from surgeries/deliveries, across the floors, and between the units. It may seem somewhat trivial but the capability of a critical care device to function during transport is a huge deal. A company was promoting a new warmer for NICU with enhanced features, including procedure lights, motion sensors, hourglass heating, in-built sensors and respiratory aids, etc. The new features were exciting but in the end, it came down to whether the product could function at full capability (without wall power) in the time it takes to bring a baby from the delivery room to the ICU. It turned out that it was not able to do that by itself, and it was significant drawback. You can buy an additional universal power supply box at an exorbitant rate for 15min of offline power, but that may not always be sufficient.

2) Speed: This is where lab-on-a-chip technologies will come in. It is surprising to know how the results a relatively simple genetic test can take several weeks to return. This can be dangerous for a patient that requires immediate treatment based on a positive result of the test. This is a very real issue, and there are already lab-on-a-chip technologies used in the hospital. If you look around, you may notice that the blood gases of the patient are obtained at the bedside.

3) Accuracy & Verification: I learnt in a conference that dosing errors are very common in any hospital. Usually, the error is noted before it causes any irreparable damage but sometimes it is not. The source of this error is either from the human (doctor, pharmacist, nurse etc.) or from the machine (dosing and prescription order systems). Fortunately, there are checks that go on at each level to make sure the prescription is right. It would be great if there was a system that could somehow eliminate all the forms of dosing errors.

Last diverse week! Gotta get my project going from now on.

I have had it with surgeries. This week I attended an arm reconstruction in the plastic surgery unit, which was great, but I think it's gonna be my last one. Nothing is wrong with it; it's just interesting for the first 15 minutes and then after that, it's just a lot of tissues with some blood being push around for a long time. I'm much more interested in trying to figure out what's wrong with the patient and what would be the best treatments. I'd be happy with just hearing about what will be done in a surgery in order to fix the problem rather than watch for 3 hours and try to figure out what's going on. I think the thing I learn the most when observing a surgery is about anesthesia. It seems so much easier in human. I'm not sure if it's because my mouse is way smaller than a person, so it's harder to maintain appropriate level of anesthesia; or may be the anesthesiologists are just a thousand times better with human than I am with mice.

Anyway, a saw or something fell on this patient's arm and almost cut off his wrist since he works as a construction worker. (And don't you dare tell me that this is too much identifiable information on a public blog. There are thousands of young male construction workers in NYC. I'll give you 50 bucks if you can actually identify this patient! --except those of you who saw the surgery, of course) To fix this, Dr. Spector and the team had to reconnect the nerve bundle. The problem is, the nerve tissue was too short to be sew back together, so they used endothelium flap to connect both nerve endings. My thought throughout this whole process was on a talk I attended at one Biomedical Engineering Society conference. One group showed that axon of a neuron can be stimulated to grow up to 15 cm during a period of several weeks if a constant, small PHYSICAL force is applied. I can't help but keep thinking that if the surgeons can preserve the nerve tissues while stretching them for a few weeks, the neurons will grow longer. They can then connect the endings without using the endothelium which doesn't conduct as well as nervous tissues. It seems like it'd work...

Hematology clinics this week was extra cool because I suggested radiation therapy for a patient with uncontrollable Chronic Myeloid Leukemia and Dr. Silver actually took it. I might start asking for a commission if he takes a few more of my wild suggestions :) The patient had very high white count among a whole bunch of other elevated components of the blood. He feels tired and sick and had insomnia and etc. due to his condition and drugs side effects. I'm not sure why, but Dr. Silver never prescribe radiation therapy. He always uses chemo drugs only.

My favorite case this week was with Dr. Prince. It was the first time I observed a physician making a diagnosis by looking at an MRI. An MRI scan of a 74 year old lady showed that she has a stenosis on the artery that goes to her left kidney. She has hypertension because of this incomplete blockage, and her right kidney is dying due to this pressure. However, she feels fine. There's no symptoms whatsoever. Dr. Prince said the location of the stenosis is an easy location to put a stent in, however, there are still risks. The dilemma is that she feels fine. Should she risk putting a stent to fix the arterial blockage? And if she doesn't have this operation, her right kidney will completely stop functioning eventually. If she opens up the blockage, then the hypertension could still remain and that will kill the currently good left kidney. I find the decision making process in order to balance the risks and the advantages more challenging and fun.

Conduct in General

Entirely Inappropriate

I can understand that we should be as immersed as possible during this term. However, I have reservations getting connected to patients who are terminally ill or patients that have a severe condition. Is it appropriate for us to learn the names of patients considering our limited time at the hospital? I feel that this practice is not appropriate for summer students.

A rough day...

Today I think reality set in. I had pretty much a normal day, but at the same time a very rough day. I started off in surgery with Dr. Scherr as normal watching a robotic cystectomy with an Indiana pouch and then left to do NICU rounds with Dr. Frayer. The difficulty began when I walked into the NICU and a group of doctors and nurses were looking at a head sonogram. First of all, the subtleties they could observe was amazing, but the prognosis was also very challenging. As we later made our rounds, I realized this was a baby I had learned the name of just yesterday. And as the doctors and nurses discussed how they would present the situation to the parents, I realized that this tiny baby will have a very rough ride in the days to come. After rounds I returned to Dr. Scherr's surgery which was going very well. The surgeons ran into some difficulties near the end as the patient had previously received radiation and some of the tissue was very fragile. Just as they were finishing though, Dr. Scherr received a phone message from his secretary. A patient from just days before, having received a robotic cystectomy and recovered very well, had fainted in his hotel, was rushed to the ER and had passed away. Dr. Scherr then left the residents to finish closing as he went to find the wife of his patient in the ER and learn what had happened.

Over the past few days I've finally had the chance to do rounds with the residents. While they didn't understand why I would do this, it was very valuable to me to be able to see patients recover. What I didn't expect was the impact of learning the patient names (which I also did in the NICU to be able to keep track of the babies). I had previously tried to avoid writing down names in order to maintain patient privacy, but at this point I feel like I was somehow dehumanizing them by not noting their names. Now I try to keep track because although the two instances mentioned above are very difficult, they're also very real. Today definitely brought me out of the solely science aspect of medicine and into the humanity aspect of medicine.

My Immersion in Radiology Department

This is already the third week of my immersion in radiology department. I find my life here is very different from my classmates: no scrubs, no rounds and no tears. I am not sure whether someone will think this can be called "not immersed yet". However, I actually feel very happy to experience this aspect of the life in hospital. Perhaps I missed many moving stories in ICU, but I learned a lot of episodes "behind the scene". I will talk about this starting from three biopsy cases to which I have been.

Case 1: X-ray-guided Transjugular Hepatic Biopsy. This is a case done at Columbia. Patient is one more-than-seventy-year-old male. The whole biopsy lasted about one hour. Sampling amount is small. There is no too much pain and bleeding after biopsy. Basically the patient didn't suffer a lot from this biopsy. Biopsy report unknown.

Transjugular hepatic biopsy is actually one of the newest technology among all hepatic biopsy methods. In US, the death rate of doing hepatic biopsy is about 1/1000. Most of them are due to the massive bleeding and collapse of diseased liver after biopsy. Considering this patient is old and his diseased liver may be too frail in this situation, this method is definitely a great choice.

Case 2: MR-guided Breast Biopsy. This is a case done at the MRI center on 55th street. Patient is one around-fifty-year-old female. The whole biopsy lasted about forty minutes. Sampling amount is relatively big. The suspicious lesion is very close to some big blood vessels, so the patient bled some after biopsy. Two samples were taken here because the patient accidentally moved her head during imaging, the location of the lesion was then changed. Because of this, patient had some small complains, but in general this biopsy was very successful. Biopsy report unknown.

MR-guided breast biopsy is better at maintaining the natural shape of breast than X-ray imaging. And it is more accurate at telling the location of lesions with the help of the guiding gird.

Case 3: CT-guided Lung Biopsy. This is a case done at Weill. Patient is a seventy-two-year-old female who had an incision of the right breast because of breast cancer ten years ago. Now a nodular solid lesion was found in her right lung. The whole biopsy lasted about half an hour. Sampling amount is very small. This is perhaps the easiest biopsy case among the three - very quick and causes very small cut. However, because of the structure and composition of lung, about 20%~25% of patients may suffer from lung collapse after biopsy. The severity and recovery of collapse vary among different patients. A quick H & E staining was done right after the biopsy. Flower-like cell clusters were found in the specimen, indicating a cancer-like lesion in the patient. More biopsy samples would be sent to Papanicolaou stain and making wax-embedded slides, so that more convincing characterizations of the biopsy sample can be made.

Although no confirmative conclusion about this patient can be made then in this case, I still felt very sorry for this lady when I was watching the biopsy. Ten years ago, she came into the hospital and lost one breast because of cancer. Ten years later, the same disease came back and might jeopardize her life and happiness again. Everything is so tricky when the moment came that as a radiologist, one learned about the coming of a horrible disease earlier than the patients and physicians. However, this radiologist must give comfort, possibility and hope to the patient when everything was not sure yet.

In this small scanning room, drama seldom happens. But all kinds of delicate struggles of inside world are going on. I can feel this on the patients by observing their move and words before and after learning about the scanning results. I can also feel this on the radiologists when they think very hard to give the most likely right conclusion on some cases to the clinicians. Here, no bloody "fighting" happens. But the things happened here give the most important support to the most thrilling surgery in ORs.