Commentary
Obesity poses challenges to all modes of gynecologic surgery from open to minimally invasive to vaginal procedures. Operating on obese women results in more intraoperative and postoperative complications, particularly with regard to blood loss, wound infections, and venous thromboembolic disease, and contributes to increased length of hospital stay (J. Minim. Invasive Gynecol. 2014;21:259-65). Obesity has also been associated with longer operative and nonoperative times in laparoscopy, compared with those for normal-weight patients (J. Minim. Invasive Gynecol. 2012;19:701-7;Gynecol. Oncol. 2006;103:938-41; J. Minim. Invasive Gynecol. 2014;21:259-65).
Dr. Leslie Clark
While it was initially felt that obese patients were poor candidates for laparoscopic surgery, it is now widely supported that minimally invasive surgery is both feasible and may be the optimal approach in this population (Gynecol. Oncol. 2008;111:41-5; J. Minim. Invasive Gynecol. 2010;17:576-82). When obese patients are able to undergo minimally invasive procedures, the result is shorter hospitalizations, less postoperative pain, a faster return to activity, and fewer postoperative wound infections (10.5% vs. 1.3%) (Ann. Surg. 2006;243:181-8). These improved surgical outcomes are seen with both laparoscopic and robotic surgeries, compared with laparotomy in obese patients (Int. J. Gynecol. Cancer 2012;22:76-81; Ann. Surg. Oncol. 2007;14:2384-91; J. Clin. Oncol. 2009;27:5331-6).
Obesity affects most organ systems, resulting in several challenges for our anesthesiology colleagues. In addition to difficult airway management, hemodynamic concerns and metabolic changes must be considered (J. Anesth. 2012;26:758-65). Physiologically, obesity results in an increased oxygen requirement, which leads to increased cardiac output, increased stroke volume, decreased vascular resistance, and increased cardiac work. These physiologic changes result in a higher incidence of hypertension and cardiomegaly in obese patients. Both oxygen consumption and carbon dioxide production are more marked in obese patients. This requires increased ventilation. Because of the excess chest wall weight with subsequent reduced chest wall compliance, ventilation is even more difficult in obese patients.
In addition to the baseline physiology of obesity, minimally invasive surgery adds the additional obstacle of abdominal insufflation. Insufflation increases the intra-abdominal pressure, leading to venous stasis as well as a further lowering in chest wall compliance and increased airway pressure (Ann. Surg. 2005;241:219-26; Anesth. Analg. 2002;94:1345-50). Finally, the need for Trendelenburg positioning for pelvic surgery further complicates an already difficult to ventilate patient.
In addition to the anesthetic challenges, obesity poses multiple challenges for the surgeon. With regard to laparoscopic surgery, key challenges for surgeons include safe and effective patient positioning on the operating room table, access to the abdominal cavity, and difficulty with surgical field visualization. Optimal positioning of the patient remains crucial to avoid nerve injuries.
Dr. Daniel L. Clarke-Pearson
The depth of the abdominal wall makes safely accessing the abdominal cavity more challenging. The thickness of the abdominal wall can place more torque on laparoscopic ports and instruments, which can require contorted positioning on the part of the surgeon. The surgeon risks significant personal ergonomic strain operating on patients, particularly obese patients (Gynecol. Oncol. 2012;126:437-42). Lastly, visualization in obese patients is impaired regardless of mode of surgery. All of these challenges often can be overcome or at least optimized, particularly in the hands of skilled surgical teams.
In addition to making the surgery more challenging for the surgical team, obesity increases the cost of providing surgical care. In fact, hospital-associated surgical costs totaled an additional $160 million spent annually on the care of obese patients, compared with their nonobese counterparts receiving the same services (Ann. Surg. 2013;258:541-53). Given the continued rise in the number of obese patients, particularly those with a BMI greater than 40 kg/m2, the surgical concerns addressed in this column will continue to pose challenges to surgeons.
Dr. Clark is a chief resident in the department of obstetrics and gynecology at the University of North Carolina at Chapel Hill. Dr. Clarke-Pearson is the chair and the Robert A. Ross Distinguished Professor of Obstetrics and Gynecology, and a professor in the division of gynecologic oncology, at the university. Dr. Clark and Dr. Clarke-Pearson said they had no relevant financial disclosures.