Conclusions

The last week of my senior project is here!  In terms of results, here are some graphs illustrating the results I collected from the tensile strength tests. I will be presenting my findings and talking about my internship experience in the beginning of May.

Thank you for following my blog for the past few weeks. I had a wonderful experience at Banner Health. Shout-out to my college counselor Ms. Mitrovich, my faculty advisor, Mr. Carey, and lastly, my on-site mentor, Dr. Truong, for all being awesome. And thanks for reading!

Cheers,

Vanessa

Week 10/ Wrapping Up

This week, I went and bought new tissue for testing, and have been preparing the samples for testing next week. The segments will be stitched with different types of sutures—Stratafix, v-loc, and ‘regular’ vicryl. The pressure will again be measured by the arterial line setup and hopefully I will be able to compare the results to see if the suture type affects burst pressure for these samples. I have also spent a lot of this week researching at home, not only reading up about compartment syndrome, but also continuing to analyze my tensile strength data. Compartment syndrome really illustrates how capillary perfusion will fall due to high pressures in an area and points out to the fact that it is unlikely that vessels reach these abnormally high pressures. Thus, for my project, instead of measuring when the fluid will begin to leak from the tissue segments, I will be focusing on whether the stitches hold at certain ‘normal’ pressures that may exist in real conditions, and not just under simulated experimental/lab conditions.

In addition to my SRP project, I spent the second half of my week visiting Cornell. I was lucky enough to dorm with one of my old friends, and even got to sit in on several courses. The campus was beautiful (but huge, walking anywhere took around 10-15 minutes) and I had a really great time.

Cornell's bell tower

I have not yet committed to a school, but nonetheless it was an amazing experience to travel to Ithaca for the first time!

Hope everyone had a similarly great week! I will be conducting the rest of my trials soon, and can’t wait to share my results with you all. I have also been working on my presentation, to share my project with the greater community, that will occur on May 7th at the . My classmates and I will be presenting our findings from the past few months—feel free to come and take a look! (More information here).

Until next time,

Vanessa

Week 9/ Hiatus

Hi Everyone—this week I did not go to my SRP site, since I fell sick with a pretty bad cold. Work to be continued next week! See you soon~

Week 8/ Throwing a Stitch Pt. 2

Hi everyone & welcome back!

As my experiments with burst pressure continues, I have relocated to a new office near Cardon’s surgery wing, where the equipment is kept. A special shout-out to Ms. Berlin, who kindly agreed to let me run these experiments in her office, despite the smell/messiness! Having brought in the tissue samples and been shown how to do a purse string suture to attach the needle/catheter to the sample, an anesthesia tech kindly helped us set-up the arterial line and showed us how to calibrate the monitor. Here is what the set-up looks like:

The apparatus I used to test burst pressure is called an arterial line. To reiterate from previous blog posts, an A-line is usually used to monitor patients in intensive care, and measures intra-arterial blood pressure.

This must be calibrated before the beginning of each test, or ‘zero’ed so that the pressure is at zero. Then, to pump fluid through the catheter and into the tissue sample, the blue tag is pulled. Once the tissue inflates, the observer would watch for signs of leaking and then record the pressure immediately after fluid can be seen.

The IV/Flushing system is controlled, in short, by a 3-way stopcock.

In terms of preparing the tissue sample, I started out with segments about 8 cm in length, sutured close on both ends. We tried running tests on these (see tissue sample with green butterfly wings), but due to the limited amount of solution/time, decided against using such large samples. Afterwards, I cut the approximately 8 cm long segments in halves and sutured up the open ends. These smaller segments are what I will be running tests on in the future!


Above is a 4 cm long segment, with a butterfly catheter attached via purse string suture. The reason for the “butterfly wings” or side flaps around the needle are to anchor it to the tissue, in case pressure causes it to pop out.

The A-line offers a wealth of information, but for this experiment, I will only be looking at the pressure (pictured above in red).

A problem that I encountered this week came from the difficulty of determining exactly when the tissue sample started leaking. Once it begins to leak, the pressure stops increasing but fluctuates quickly. It was pretty difficult to get a precise measurement. In future testing, Dr. Truong suggested that I use food coloring so that the liquid that spills out will be easier to visualize. This, however, involves flooding the entire bag of saline solution (and even injecting the food coloring into the saline bag), which may be difficult to carry out and cause the saline bag to be unusable after my experiments.

These few hours that I spent working on testing burst pressure are some of the most interesting I have experienced in the project thus far!! It has been really exciting to be able to get the chance to use this equipment and even run tests with it.

Hope everyone has a great week!

Vanessa

Week 7/ Throwing a Stitch Pt. 1

Hey Everyone!

I have finally started to prep for my experiment on testing the difference in burst pressure on tissues sutured with V-loc, Stratafix, and regular sutures. For the methodology, I will be taking segments of pig uterus of approximately 5 cm in length, closing both ends with running sutures, and inserting a catheter in the mid-section of the segment to infuse/inflate the pipe-like structure with fluid. The pressure will be measured by the arterial line, which is connected to the catheter (see previous blog post for more details on the A-line).

I am planning to do 10-15 trials each per type of suture. Next week I will begin running tests, but as for this week, I will be preparing the segments to be tested.

To go in a bit more detail, a running stitch is one of the most basic stitches in surgery. It isn’t as pristine in appearance when compared to the other sutures (in which the suture can be hidden and only the knots can be seen on both ends). In the procedures I have seen thus far, the incisions have all been closed with the intention of minimizing damage to the skin’s appearance: in other words, so that sutures are not visible when looking at the wound. This is called a subcuticular suture.

To see how a running stitch is done as compared to a subcuticular suture, click on the highlighted links!

Pig Uterus! D’:

Working with pig uterus wasn’t as gross as I had expected, but the smell is slightly strong (especially since (as of now) I am working in the clinic’s Office). Hopefully by next week, there will be a room that I can use to run my experiments without the smell affecting everyone. If anyone is curious, pig uterus reminds me a lot of pig intestine (or rather, what I would imagine intestine to look like??) Dr. Truong even agreed with me—if the packaging had not labelled it as ‘Pig Uterus’, I’m not sure I would have known the difference.

This week when I met with Dr. Truong, I was allowed to enter the physician's dining hall, which is only open to physicians and studying med students! Eating here was super intimidating, especially as I sat next to so many doctors and professionals.

Before signing off, Happy Easter everyone! Here’s a great surgical video (warning: graphic content) to celebrate the weekend. See you guys next week!

Vanessa

Week 6/ Results

Hi Everyone!

It has been an incredible week, even without stepping into the OR once while at Banner. Over the past few days, I spent several hours completing the experimental part of my project—the portion concerning tensile strength, at least. I conducted tests that compared how tensile strength varied with the following features of sutures:

1. Size. I used only what was available in the office, so to compare different sized sutures, I used 2-0, 3-0, and 5-0 Monocryl.
2. Monofilament vs. Multifilament (braided). To compare these I used 4-0 Ethilon (monofilament) and 4-0 Nurolon (braided), both nylon sutures.
3. Barbed vs. Regular. V-loc 180 (absorbable, barbed) and Coated Vicryl (regular, braided)

V-loc 180 Sutures!!!!!!!

To see a spreadsheet of my results, click here. In the beginning of next week I would also like to run some tests on the tensile strength of Stratafix sutures to compare to the results for the V-loc sutures. They are quite similar barbed sutures but provided by a different company, Ethicon. I will also begin to analyze the results gathered from the tensile strength tests. To do so, I will be finding a 95% confidence interval for each type of suture, and compare the different properties to see if there is a statistically significant difference (s/o to Mr. Peacher and our Stats class!)

Next week, I will be starting a new phase of my project. Using sutured tissue, I will be measuring the burst pressure of the tissue samples once they have been closed with either V-loc, Stratafix, or regular sutures. To summarize, burst pressure describes the maximum amount of pressure an inflated object (a pipe, usually) can withstand before the apparatus begins to leak/break/tear. To conduct this experiment, I will be using an arterial line to measure the pressure. It works, generally, like this:

The A-line will be borrowed from the ICU and the setup will be done by hospital tech, who have generously volunteered their time. Thank you so much! On another note, the tissue I will be using to test burst pressure is going to be pig uterus...Apparently this, along with the pig’s foot, can be obtained at your local asian market. Wish me luck :')

Hope that everyone has a great weekend! As colleges finally begin to release admissions decisions as well (!! D:), I hope that everyone receives good news!!!

Best,

Vanessa

Week 5/ Spring Break

This week was my ‘Spring Break’, but I still got a chance to visit the office on Friday. Dr. Truong got me a set of surgical tools (needle driver, scissors, and a pick-up) to begin practicing suturing!!

From my observations so far, suturing seems to require a lot of fine motor skills. You need to hold and wield the needle driver with precision and ease—something that can only be gained through hours of practice and hands-on experience.

Surgical scissors (bottom), needle driver/holder (middle), pick ups (top).

Today was my first day learning how to suture! I even brought a pig’s foot with me to practice on (sadly, we never got a chance to use it). So far, I’m pretty terrible. However, I did successfully learn how to tie an instrument’s tie! This tie is different from the knots I learned before in that it uses the needle driver as part of the process. It’s a lot easier than it looks and comes in handy in a procedure—in fact, most of the ties I have seen done in the OR are instrument ties.

Here’s a video that covers different types of suturing techniques, if you’re curious:

https://www.youtube.com/watch?v=TFwFMav_cpE

Anyways, despite my lack of a natural affinity for suturing, I’ve had an exciting day at Banner. Hopefully, with more practice throughout the next few weeks, I can learn the basics and be able to stitch up a cut, and even incorporate suturing into my project.

A day in spent in the office with my new suture kit :)

Holding a needle driver!!! (note: probably incorrectly)

Speaking with Dr. Truong and getting instructed on how to suture today really made me realize how amazing it is to be able to learn from a surgeon as a high school student with no medical training. I’m so grateful for the hands-on experience, and look forward to learning more in the remaining weeks.

Until next time,

Vanessa