Week 7&8

On the Tuesday of the 7^th week, I had the opportunity to join Dr. Spector’s team with Terence and Aaron to observe a mandible reconstruction surgery. A bone tumor, which was excised in the first stage of the surgery, was diagnosed on the right side of the patient’s lower jaw. To reconstruct the mandible, a piece of fibula flap without skin part is used to restore the defect. A CT-scan 3D printed skull of the patient had been made beforehand as a guidance to excise the tumor structure; and a template served as fibular guide was designed to cut the fibular in the precise location and angle to fit the defect. Because I had to shadowing Dr. Cross earlier that day to see patient, I came to the O.R. a couple hours late and missed the mandible remove part. When I entered the O.R., three teams of doctors including head and neck team, fibular team, and plastic surgery team were working on the patient simultaneously. There was a huge ear-to-ear cut on the patient’s neck and all the skin above had been lifted up to expose the mandible with clear margin for the bone resection. The fibula procedure took a while because the cuts and the holes for the implant need to follow exactly the size and the alignment of the guidance. But once it was removed, the fibula flab fit instantly and perfectly into the mandible. The last part of the surgery was operated with the aid of a microscope to reattach the vessels to neck tissue. Two veins and one artery of the similar sizes from the neck were chosen as the candidates. The arteries were attached by suturing end to end. The veins attachment, due to their smaller size, were performed by anchoring the ends of both veins on a small plastic rings with needles and then being clipped tightly to prevent leaking. The entire surgery took more than 8 hours to be finished. It is very amazing how the pre-designed guide and template help doctor perform the procedure precisely. The functional and aesthetic outcomes were incredible in comparison with those simile surgeries without patient personal guide.

On Thursday morning, I attend the TERR meeting in which a postdoc of Dr. Suzanne Maher presented his research work on stress distribution on knee models of patients with meniscus autograft transplantation. The study utilized MRI imaging technique to monitor the cartilage morphology and mechanical integrity change at the load of half body weight. Based on the MRI results, the decrease in T1ρ signals indicates the decreasing proteoglycan level which is in correlation with a decrease on the hydration level.  T2 value change was also in correlation with the water content and therefore it could be used as a double security on research results. The stress and stain distribution upon the same loading was also monitored by MRI and the results were compared to the data obtained by an intraoperative method. By comparing the results of two methods, the variation on contact surface area and peak stress values were found to be very similarly in each method, which indicated the potential for the MRI to serve as a surrogate non-invasive monitoring technology.

During the last few weeks of the program, I had started a research project in collaboration with Dr. Jason Spector to develop a substituent for current mainstream product in wrinkle smooth market—JUVÉDERM®. JUVÉDERM® is a FDA-approved injectable filler used by cosmetic and plastic surgeons to smooth facial wrinkles and volumize deeper folds. The major component of JUVÉDERM®, called hyaluronic acid (HA), is a family of naturally occurring linear polysaccharide that can be found in skin, connective, epithelial, and neural tissues. To achieve cheek augmentation, cross-linked HA hydrogels can absorb large amount of water and expand up to 1000 times of its own volume upon injection intradermally. Each injection cost at a price of over $500. The purpose of this project is to design and synthesis an effective JUVÉDERM® substitute that has similar/better characteristics but costs less.

In summary, a fantastic summer with awesome experience in hospital immersion is over. I have learned a lot of knowledge in orthopedic field as well as in vascular surgery and plastic surgery. Such experience will greatly benefit my future PhD career and I am looking forward to continue my collaboration with the doctor in the following years.