American College of Surgeons Clinical Congress, Oct. 11-15, 2009
The American College of Surgeons 95th Annual Clinical Congress took place October 11 to 15 in Chicago. This year's Congress included over 100 panel sessions, video-based education, and hundreds of scientific and technical exhibits. The Clinical Congress is the largest educational meeting for surgeons in all specialties in the world and attendance at this year's meeting was expected to exceed 15,000, including surgeons and other health care professionals. In addition to clinical and scientific research, topics included the surgical work force crisis, ethical considerations, health policy, minimizing surgical risk, and an update on the management of the war-wounded.
Angela B. Smith, M.D., of the University of North Carolina in Chapel Hill, presented results from a phase II clinical trial in which the targeted anticancer therapy erlotinib was evaluated in patients with advanced bladder cancer. Erlotinib is an orally available small molecule inhibitor of the epidermal growth factor receptor (EGFR), a protein overexpressed in many cancers. According to Smith, EGFR expression is correlated with high stages and grades of bladder tumors, increased likelihood of bladder cancer metastasis, and decreased overall survival.
A total of 25 patients with bladder tumors that had invaded the muscle layer were treated with a four-week course of erlotinib prior to undergoing surgery. Of these patients, 16 were still alive after five months, and 10 patients had no evidence of disease. Following erlotinib treatment, three-quarters of patients (75 percent) had organ-confined disease. Additionally, 25 percent of patients were pathologically free of disease, and 35 percent were pathologically downgraded to indicate they only had superficial involvement of the bladder.
In a statement, Smith said "it's too early to tell exactly what the outcome of treatment will be, especially with such a small sample size of patients in the study and lack of a control group. But these preliminary results are encouraging."
Michael Morgan McNally, M.D., of East Carolina University in Greenville, N.C., reported research showing that patients who take statin drugs may have better results and lower costs in aortic aneurysm repair.
In an investigation of 401 cases of abdominal aortic aneurysm repair surgery at their institution, the researchers found that patients who used statin drugs experienced fewer complications and a lower chance of postoperative death. Interestingly, this result was maintained even though statin users had more concurrent health problems compared with control patients. Compared with 5 percent of patients who did not take statins, none of the patients who were taking statins died in the study. In addition, the total costs associated with the repair surgery were lower for statin patients compared with nonstatin patients, regardless of the surgical approach used ($33,237 versus $36,442 per patient for the endovascular approach; $18,647 versus $22,440 per patient for the open approach).
According to a statement by McNally, "the study findings point to the powerful risk reduction ascribed to statins and highlights the importance of giving these drugs to patients undergoing cardiovascular procedures." McNally further elaborated that a significant benefit was associated with statin use even after only 30 days of taking the drug.
Lesly A. Dossett, M.D., of Vanderbilt University in Nashville, Tenn., presented findings which showed that use of the common anti-clotting agent warfarin may cause problems for some trauma patients, especially elderly patients.
In a large-scale analysis of the National Trauma Databank of the American College of Surgeons, which included data from 1.2 million patients from 402 centers, the investigators found that warfarin use was linked to a 30 percent increased risk of death in trauma patients overall, as well as a 20 percent increased risk of death in patients 65 years and older. In addition, warfarin use in patients aged 65 years and older was found to have nearly doubled from 2002 to 2006, growing from 7.3 percent to nearly 13 percent.
However, Dossett acknowledged that factors such as additional health issues may explain this increased risk of death. Also, no definitive connection was established between warfarin use and post-trauma death. In a statement, Dossett added that "trauma is [a] relatively rare event for elderly patients, so if they have a good solid reason for taking warfarin, no one would suggest that they not take it."
In a separate statement, J. Wayne Meredith, M.D., of the American College of Surgeons Trauma Programs suggested "this paper is a call to evaluate the risk and benefits of anticoagulation before prescribing them."
Juliane Bingener, M.D., of the Mayo Clinic in Rochester, Minn., presented advancing research on a new incisionless operation used to patch stomach ulcers and other digestive tract perforations. The NOTES (natural orifice translumenal endoscopic surgery) is an endoscopic procedure in which the scope, together with a suturing device, is inserted through the mouth into the stomach in order to repair ulcers.
To date, the use of the NOTES procedure has been restricted to laboratory pigs. However, according to Bingener, successful animal studies have paved the pathway for advancement into human clinical trials. In a statement, she suggested that unlike conventional surgical procedures used, "our initial animal data suggests that we may not need quite as much peritoneal pressure with endoscopy. The advantage of lower pressure is more cardiovascular stability for the patient."
Currently, the investigators are seeking to receive approval for using the NOTES procedure in human volunteers.
Claudius Conrad, M.D., of Massachusetts General Hospital in Boston, presented research regarding a novel treatment for pancreatic cancer which uses bioengineered stem cells. The bioengineered construct used in the treatment, nicknamed "Trojan Horse", is comprised of engineered mesenchymal stem cells derived from the bone marrow. When the tumor actively recruits these stem cells, a gene product that is toxic to tumor growth is then expressed. Because of its mechanism, the stem cell construct may provide a way of selectively targeting tumor cells with minimal side effects.
According to a statement by Conrad, "we developed our concept of using stem cells to target tumor cells because the homing drive of aggressive tumors like pancreatic cancer is so strong that genetically engineered stem cells can help destroy the tumor. Also, the unique signals in the tumor microenvironment can help make the therapy cancer-specific once the modified stem cells have been homed."
Currently, research surrounding these bioengineered stem cells is limited to animal models. Based on promising results, the researchers are developing protocols with the plan of eventually applying for U.S. Food and Drug Administration review.