Obesity is a major surgical obstacle. Obesity not only decreases access to the surgical field but also alters the anatomical relationships between the abdominal wall and the abdomen. The surgeon must understand not only anatomy in normal-weight women but also how obesity alters normal anatomy. Obesity affects the choice of incisions, size of incisions, closure of incisions, and choice of instruments (retractors, long instruments, etc.). Obesity affects these decisions about open surgery and minimally invasive surgery (MIS).
Before booking a case surgeons, must evaluate their own surgical skills, their hospital’s operating room, and the other specialists needed to care for the patient (Table 33-1). The skill and experience of the surgeon are paramount. If experienced in the needed operation, it may only be necessary to ask a more experienced surgeon who has dealt with obesity in the operation to assist. If the surgeon is relatively inexperienced, it may be prudent to refer the patient to a more experienced surgeon and serve as assistant at the operation if possible. The surgeon must be certain that the equipment needed is available, which may mean a wide operating table designed for obese patients, long instruments, proper retractors, and so on. Obesity is a significant problem for the anesthesiologist, and the surgeon must be certain that the anesthesiologist is comfortable with the anesthetic challenges posed by obese patients (see Chapter 25). Experienced assistants are important in an operation in which obesity is a significant problem. A preoperative conference with the operating room personnel, the anesthesiologist, and the assistants can be helpful in performing the operation safely.
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Obese women may have important comorbidities. Primary care physicians and other subspecialists need to be aware of the upcoming surgery to advise the appropriate preoperative evaluation and treatment of medical problems. Routine preoperative clearance by the patient’s medical physician will identify problems and allow optimization of care for these diseases prior to surgery. This is especially true in patients with diabetes, hypertension, vascular disease, heart disease, and asthma. Nutritional assessment and recommendations should be addressed as many obese patients may have significant nutritional deficiencies.
Preoperative anesthesia evaluation is crucial. The anesthesiologist will evaluate the airway, plan for a difficult intubation, and evaluate medical problems of special importance to safe anesthetic care and identify any further preoperative workup that will be needed. Also, during this preoperative visit the anesthesiologist will have the opportunity to discuss these issues with the patient.
Obese patients are at high risk for deep vein thrombosis (DVT) and possible life-threatening sequelae, including pulmonary emboli (PE). Prophylaxis with sequential compression devices and heparin is advised. Shorter-action unfractionated heparin should be employed during surgery, but if there is a low probability of continued blood loss, patients can be switched to long-acting, low molecular weight heparin postoperatively so that only 1 injection per 24 hours is needed rather than administering unfractionated heparin more frequently. Ambulation may be difficult but is perhaps the most important aspect of DVT prophylaxis. You should consider continuing prophylaxis for 4 weeks after surgery.1 While this will decrease the risks for the development of DVT/PE, it will not eliminate the possibility of a thrombotic event. The patient should be counseled concerning the signs and symptoms of thrombosis that require evaluation.
Obese women are at increased risk for wound infection and should be given prophylactic antibiotics. Antibiotics should be appropriately dosed based on weight and need to be administered far enough prior to the incision to ensure that adequate tissue levels are present. Fat has decreased blood supply, and extra time may be needed for absorption. The precise time required for tissue levels is unclear, but 15–60 minutes prior to the incision should be sufficient.2 If surgery is prolonged or there a large amount of blood is lost, then antibiotics should be redosed. Postoperative antibiotics should not be given in the absence of an established infection.
Intensive care admission may need to be scheduled in advance of the operation or intraoperative events may require emergent admission to the intensive care unit; the surgeon must be certain that such intensive care is available. Prolonged intubation of obese patients may be required, and intensive care unit admission in many hospitals is necessary for ventilator support and management.
Medical colleagues may be needed for help in postoperative care. Glycemic control has been shown to be important in reducing the risk of infection both preoperatively and postoperatively. Many of the comorbidities present in obese patients may be exacerbated postoperatively and require expert management. If medical specialists were involved in the preoperative care of the patient, they will be aware of the patient’s needs and familiar with the patient’s care.
Nursing care for obese patients is challenging but important. There must be enough nursing staff available to assist patients in promptly getting out of bed and to assist in walking. The proper equipment must be at hand, such as hoists, to allow the staff members to help the patient out of bed and avoid injury to themselves. Unfortunately, injuries to the staff in assisting obese patients are common.3 There is evidence that recommended DVT prophylaxis with sequential compression devices (SCDs) is routinely ignored by patients and nursing staff.4 It is important for everyone involved in the care of obese patients to be aware of the importance of postoperative compliance with recommendations.
There are three aspects of anatomy that must be considered: the bony pelvis; abdominal wall anatomy (muscles, fascias, vasculature, nerves); and the shape and relationship of the overlying fat. A review of normal anatomy may be found in any basic anatomy text.
The diameters of the bony pelvis are important but often ignored. There is a significant difference in the diameter 3 cm above the pubic symphysis (location of a Pfannenstiel incision) and the diameter between the anterior superior spines, resulting in greater access to the pelvis if the incision is made between the anterior superior spines (Figure 33-1). While a Pfannenstiel incision for a cesarean section places the surgeon directly above the lower uterine segment, this incision limits the surgeon access in any other type of surgery. This is rarely the incision of choice in obese patients undergoing gynecologic surgery.
Obesity does not alter the underlying abdominal wall but can markedly alter the surface relationships to the abdominal wall (Figure 33-2). To judge the relationship of surface markers and the abdominal wall, the surgeon must take into account the thickness of the overlying fat and the shape of the fat. An “apple” body shape affects the distance between the surface and the abdominal wall but may not greatly affect the relationship to the abdominal wall. However, a large panniculus (pear body shape) can dramatically alter these relationships. With a large panniculus, the umbilicus no longer marks the bifurcation of the aorta but instead places the umbilicus over the lower pelvis. Because of this relationship, a transverse incision at or above the umbilicus (often with splitting of the rectus muscles) may provide excellent exposure for gynecologic surgery. While the final decision may need to be made after induction of anesthesia, the surgeon must discuss the incision possibilities in depth with the patient preoperatively.
