November 2011 (Part 2)
By Megan Rathfon, OREXer ’11-12
To start off the day Dr. Liu led the residents through a question and answer session and discussion about pancreatitis. They discussed treatment to prevent shock and multisystem organ failure, fluid volume, when surgery is indicated, how to diagnose biliary pancreatitis and gallstone pancreatitis, enteral feeding, antibiotic use, and laparoscopic cholecystectomy (lap chole).
My day began by observing a relatively quick surgery, an open carpal tunnel release on a 39-year-old female. Circulator Stefanie Snodgrass, PA Jen, and Surgery Tech Kelley explained what was going on while Dr. Jain and Dr. Bobrowsly provided anesthesia and Dr. Patel operated. Carpal Tunnel Syndrome is an entrapment idiopathic median neuropathy, causing numbness of the thumb, index and ring finger, pain and other symptoms due to compression of/pressure on the median nerve at the wrist in the carpal tunnel. The median nerve and the tendons that flex and curl your fingers go through the carpal tunnel passage in your wrist. Dr. Patel opened up the hand at the center of the palm, just above the wrist and then cut through the carpal transverse ligament to ease pressure on the median nerve. In carpal tunnel release surgery, the goal is to divide the transverse carpal ligament in two. This is a wide ligament that runs across the hand, from the scaphoid bone to the hamate bone and pisiform. It forms the roof of the carpal tunnel and the surgeon cuts across it so that it no longer presses down on the nerve inside.
The second surgery was a right retromastoid craniotomy with excision of mass, also done by Dr. Patel, with anesthesia provided by Dr. Bobrowsky. PA Larry Barden and CNT Stefanie Snodgrass were also there and helped explain what was occurring. The patient was diagnosed with a cerebellopontine angle mass. The patient has had a benign mass pressing on his auditory nerve and has been unable to hear for 20 years. It was decided to undertake the 5-hour excision procedure because the tumor was now causing pain and seizures. The surgical procedure is slow and complex because the tumor is next to the brain stem and had grown into it slightly. The tumor will eventually re-grow after removal, however, it is slow-growing and will probably not grow into the brainstem. Therefore, the surgery should help preserve the patient’s current functionality. The tumor could not be treated with chemotherapy because it divides too slowly, however it is thought that chemotherapy may be able to slow local recurrence.
Dr. Bobrowsky explained that the patient, a 56-year-old male, was given general and local anesthesia. Anesthetic included civaflourine, propofol, fentanyl, versed and lidocaine (muscle relaxants for intubation), the decongestant Neo-synephrine (phenylephrine), a pure alpha receptor agonist and has both venous and arterial constrictive effects and treats arrythmia and hypotension, Zofran (odansetron) for nausea and vomiting, and vancomycin Ancef (cephazolin) cephalosporin antibiotics.
A neurophysiologist attached needles to the patient’s cranial nerves, in order to monitor responsiveness, and electrodes to send signals from the brain to the arms and legs. The patient’s head was placed in a frame and the surgeon made markings on the patient’s head and neck. To create a sterile field they stapled a blue cloth to the patient’s head. The surgeon first looked for the large blood vessel in order to avoid it. He then cut through the scalp and the transverse sinus to the sigmoid sinus, the sigmoid process being used for a waypoint. The artery was held up and tied out of the way using blue and white strips. The sensors, attached to cranial nerves 7, 11, and 12 monitored the patient’s brain activity during the process and often the surgeon would ask if they had touched a particular nerve, for example, the 5th cranial nerve (trigeminal nerve).
The tumor was considered a soft tumor and had many blood vessels surrounding it. The tumor was broken apart using ultrasonic waves that don’t damage normal tissue (it is set for the type of tissue the surgeon is trying to resect) and then aspirated. There was a lot of fibrous tissue with numerous psammoma bodies (core or tips of papillae are calcified). Often removed tumor samples are sent to pathology, but the physician said that in this case the sample was not sent to pathology because results would not alter the treatment plan now or in the future. After the surgery the patient was taken to the ICU so that he could be monitored for hemorrhages, drowsiness, and weakness and a follow-up CT scan. If the scan shows bleeding the patient will be brought back to the OR to stop the bleeding. The procedure was fascinating because I learned about all of the cranial nerves and had a discussion about various types of tumors.