Category Archives: blood coagulation
Written by Xiteng Yan (class of 2014-2015)
Dr. Harken’s lecture focused on the treatment of venous thromboembolism and the problems with blood coagulation. The lecture was complex and fast-paced, and I found it challenging to keep up and understand the overall picture. First, Dr. Harken discussed the diagnosis of an illness named BPT. The symptoms include pain, swelling, and skin changes. Diagnosis can be further verified by an ultrasound, which has an accuracy of 70%, and a venogram measurement, which has an accuracy of ~100%. Dr. Harken then went on to discuss the differences between patient groups (e.g. medical patient vs. ICU medical patient vs. general surgery patient) and the unique risks they each face. For instance, stasis, hypercoagulability and tissue damage are some problems that afflict general surgery patients. From this topic, Dr. Harken segued into a quick overview of the coagulation cascade and the two pathways that define it: that resulting from damaged surfaces and that resulting from trauma. Heparin, a blood thinner, was reintroduced. Dr. Harken posed a question to the residents: “what happens when someone starts bleeding from Heparin?” The answer was to simply wait and give the patient blood since Heparin has a short half-life. The alternative is to give protamine, a drug that binds to heparin to reverse the anti-coagulating effect, with calcium, which counteracts the hypotensive affect of giving too much protamine. To conclude the lecture, Dr. Harken discussed two papers that focused on anti-coagulation drugs (for one of the papers, he notes that more than half of the writers were employees of the company that manufactured the tested drugs, suggesting the pressure for positive results and thus the presence of bias)
The first surgery I observed was a bilateral laparoscopic tubal ligation. The attending was Dr. Valentine, and Dr. Lee assisted him. The patient was a middle-aged, Hispanic woman. To prepare her legs were slightly elevated – almost as if she were giving birth – and her arms were placed near perpendicular to her sides. During this time, Dr. Valentine introduced himself to me and explained that the patient was getting “her tubes tied.” When Dr. Lee arrived at around 8:30AM, the surgery began. First, the patient was fitted with a catheter. When this was completed, Dr. Lee and Dr. Valentino made incisions on the belly button to create an opening for the laparoscopic portals, or trocars. Two additional trocars were inserted on the lower left and right abdomen. The insertion of these devices was quick, and soon enough, the laparoscopic camera and instruments were inserted. Using the laparoscopic instruments, which appeared to burn through and then seal the tissue, Dr. Valentine and Dr. Lee removed both of the fallopian tubes. To my surprise, the phrase “getting one’s tubes tied” was a misnomer – the fallopian tubes were not constricted but removed completely.
Once the procedure was completed, Dr. Lee told me that there was an alternative called Essure. For the Essure procedure, the patient is often left awake. The doctor would go through the vagina to place implants into the two fallopian tubes. These implant cause scarring and will ultimately seal the tubes if everything goes as plan. According to Dr. Lee, Essure is safer than bilateral tubal ligation because no incisions are made and general anesthesia is avoided. The downside to Essure is that the process is lengthy and not foolproof as complete removal of the tubes (if the implants do not seal the tubes fully, then the procedure fails).
Following the tubal ligation, I stayed to watch the next scheduled operation, which was a laparoscopic abdominal hysterectomy (the removal of the uterus). For this case, Dr. Lee was the main attending, with Dr. Valentine assisting her. The patient was a middle-aged, African American woman. The set-up and patient preparation was more or less the same as the previous operation: the positioning of the patient, the location of the incisions, the positioning of the laparoscopic instruments, etc. The first structure to be removed was a T-fibroid, or a mass of muscle, on the abdomen. The fibroid was like a golf ball in terms of size, shape, and color. Once this structure was removed, Dr. Lee and Dr. Valentine turned their attention to the connective tissue linking the uterus to the abdomen wall. Using the laparoscopic instruments, they slowly worked their way through the connective tissue. After reaching a certain depth, the amount of blood flowing into the abdomen increased. The problem of blood proliferation became a concern, and a suction tube (as well as new laparoscopic instruments) was brought in. However, neither of the doctors was truly alarmed, so I don’t think that it was an emergency. After Dr. Lee and Dr. Valentine worked their way through half of the uterus’ base on the abdomen, I excused myself for the day.