Positioning obese patients for minimally invasive gynecologic surgery

Instead, a supraumbilical or left upper quadrant site for initial entry enables optimal triangulation of trocars and visualization of disease. The trocars must then be placed more lateral and cephalad than in thinner women. In doing so, risk to the inferior epigastric is mitigated. Moreover, longer trocar lengths (150 mm) may be required.

To utilize an umbilical entry, it is imperative that the panniculus be placed cephalad to a position between the two anterior iliac spines (Obstet Gynecol. 1998 Nov;92[5]:869-72.). By doing this, the umbilicus is now repositioned relative to the bifurcation of the aorta similar to the thinner patient. This can either be accomplished using assistants to move the panniculus cephalad or taping the panniculus.

Alternatively, if the Hasson technique is not utilized, a Veress needle (50 mm in length) may be used. Based on MRI and CT visualization, Dr. Hurd has long recommended using a 90-degree angle in the obese population, compared with a 45-degree angle in nonobese women (J Reprod Med. 1991;36[7]:473-6.).

I usually place the patient into a moderate Trendelenburg position before docking the robot and observe the patient’s cardiac and respiratory responses to the induction of anesthesia. Adjustments in the degree of Trendelenburg positioning, the insufflation pressure level, and the ventilation settings can then be made if necessary. Occasionally I will decrease the insufflation pressure from 15 to 12 mm Hg, for instance, to accommodate ventilation needs.

A note from Dr. Charles E. Miller, Master Class Medical Editor

It must be recognized that not all physicians agree with the use of shoulder braces. In a review of literature on brachial plexus injuries in gynecologic surgery during 1980-2012, Dr. Nigel Pereira and his associates identified eight case reports, all of which involved Trendelenburg positioning and seven of which utilized shoulder braces. In their evaluation of the literature, the authors concluded that “the force of the shoulder braces on the clavicle and scapula opposes the force of gravity on the humerus, thereby stretching the brachial plexus and leading to nerve injury. This is particularly exaggerated when the arm is hyperabducted (less than 90 degrees), the head is laterally flexed to the opposite side, or the abducted arm is sagging.”

The authors also point out that longer times spent under general anesthesia (commensurate with increased operating times) increase the risk of brachial plexus injury “by increasing joint mobility (particularly when muscle relaxants are used) because the neighboring bony structure is more likely to compress or impinge on the brachial plexus” (CRSLS e2014.00077. [doi:10.4293/CRSLS.2014.00077]).

More pearls from Dr. Miller

Preoperative care. Prior to surgery it is important to examine a patient’s panniculus closely for evidence of infection. As the area underneath the panniculus receives little oxygen, it is at greater risk for both bacterial and fungal infections. If infection is noted, treatment prior to surgery is strongly recommended. Moreover, as the skin under the panniculus is often times “broken down,” which can compromise healing, lateral incisions should not be made in this area.

Since obese women have more severe comorbidities (such as metabolic syndrome, obstructed sleep apnea, coronary artery disease, poorly controlled hypertension, and a difficult airway) and a greater risk of perioperative complications than women who are not obese, they generally require a more-extensive preoperative work-up and additional perioperative considerations. If the minimally invasive gynecologic surgeon is uncomfortable with evaluation of cardiac and pulmonary status, medical clearance and perioperative consultation with an anesthesiologist prior to surgery is strongly recommended.

Perioperative care. There are no studies in the literature supporting the use of antibiotic prophylaxis prior to surgery despite the increased risk of postoperative wound infection in morbidly obese patients. Increased risk of surgical site infection post abdominal hysterectomy has been noted in women with a BMI greater than 35. Therefore, consideration should be given to the use of prophylactic antibiotics. For patients weighing more than 80 kg, I advise using 2 gm prophylactic cefazolin; increase this to 3 gm in patients that weigh more than 120 kg.

The morbidly obese patient is also at greater risk of deep venous thrombosis, especially when the procedure is lengthy. Sequential compression devices are essential. Moreover, use of such antithrombotic agents as Lovenox [enoxaparin] and heparin should be considered until the patient is ambulating.

Postoperative care. It is imperative to stress the need for extensive pulmonary toilet or hygiene (i.e., coughing and breathing deeply to clear mucus and secretions from the airways) as well as early ambulation. The patient should also be counseled to use pain medication judiciously. And until the patient is mobile, the use of antithrombotic agents, such as Lovenox and heparin, should be continued.