[ Editorials | Letters | Selected Articles | Departments and Series | Patient Handouts | Index ]

Minimally invasive surgery series

Laparoscopy in the Obese Gynecologic Patient

Colleen L. Casey, MD; Arnold P. Advincula, MD; William M. Burke, MD

Minimally invasive approaches to both simple and complex gynecologic problems have increased dramatically in popularity over the past 10 to 15 years. This trend has been driven not only by more laparoscopic surgical training during residency, fellowship, and posttraining practice, but also by rapidly developing technology and increasing public awareness of the potential benefits of laparoscopic procedures. Further, considerable data have been published demonstrating both the feasibility and efficacy of laparoscopic approaches to gynecologic problems that were historically treated via laparotomy. These data have been especially relevant with regard to severe endometriosis, adnexal masses, and gynecologic malignancies. Thus, the ability of gynecologic surgeons to offer minimally invasive procedures to all of their patients has become paramount in the practice of obstetrics and gynecology. Therefore, it is important for any practicing gynecologic surgeon to understand the potential challenges of laparoscopic surgery. One of these challenges is the minimally invasive approach to the obese patient. This article discusses the problem of obesity in the United States, provides some basic definitions and calculations related to the disease, reviews some of the literature supporting laparoscopic surgery in obese patients, and offers some "surgical pearls" to aid in the successful completion of minimally invasive gynecologic procedures in this patient population.

OVERVIEW

Obesity in the United States is a major national health concern. According to the National Heart, Lung, and Blood Institute, it is estimated that 97 million adults in this country are overweight or obese.¹ A more relevant statistic for the practicing gynecologist is that according to recent data collected from the National Health and Nutrition Examination Survey, the age-adjusted prevalence of obesity was 34% in adult women aged 20 to 74 years from 1999 to 2000.² Moreover, obesity has been associated with an increased risk of complications from hypertension, dyslipidemia, type 2 diabetes, coronary artery disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and endometrial, breast, colon, and prostate cancers.

Obesity is generally classified by calculating the patient's body mass index (BMI) using a formula that divides her weight by her height squared—ie, BMI = kg/m², or BMI = lb/in² ´ 703. Obesity is commonly defined as a BMI of 30 or higher, and extreme obesity as a BMI of 40 or higher (Table).

View This Table

Table. Classification of Obesity by Body Mass Index3

Waist circumference and waist/hip ratio (WHR) are also methods for assessing the severity of a patient's obesity. Waist circumference has been positively correlated with abdominal fat content, but when evaluating a patient for fat distribution, the WHR seems to be of greater relevance. A WHR exceeding 0.85 indicates android or abdominal obesity. These patients have adipose tissue that is mainly distributed over the supraumbilical area, trunk, and arms. Typically, women have a gynoid adipose distribution—ie, the adipose tissue is mainly distributed in the subumbilical area and over the hips and thighs—so that women with an android fat pattern are at particular risk for complications of obesity.⁴ Use of these methods for assessing a patient's weight status is essential for planning laparoscopic surgery and for predicting some of the challenges that may arise both perioperatively and intraoperatively.

back to top

RATIONALE

The prevalence of obesity among women in the United States presents a growing challenge for all physicians, especially OB/GYNs. Not only must these specialists provide comprehensive care for obese women with multiple medical problems, but they often face the challenges of surgery in such patients. It is well established that surgery in obese women is technically difficult. Preoperatively, it is crucial to ensure that these women are medically stable and of reasonable operative risk. Appropriate preoperative testing should be ordered as clinically indicated. Perioperatively, obese patients are at higher risk of upper airway obstruction and difficult intubation. Specifically, a 1-cm increase in neck circumference places a patient at a 1.13-fold increased risk of unsuccessful or complicated placement of an endotracheal tube.⁵ Anesthesia induction, maintenance of sedation, and waking can also be problematic for anesthesiologists attending an obese patient. Postoperatively, it has been demonstrated that obese patients have an increased risk of atelectasis, pneumonia, deep venous thrombosis, pulmonary embolus, ileus, and wound infection. These risks have also been shown to be increased with more extensive laparotomy procedures, often leading to slower return of bowel function, prolonged immobilization, and longer hospital stays.^{6, 7}

Laparoscopy provides an alternative to laparotomy for a number of surgical procedures in obese patients that may result in fewer operative complications, shorter hospital stay, and more rapid recovery. Perhaps one of the most well known applications of laparoscopy in obese patients is the minimally invasive approach to bariatric surgery. The feasibility of this technique has been demonstrated in multiple studies.^8-11 Laparoscopic gastric bypass and gastric banding have been shown to result in similar weight reduction when compared with the traditional open procedures while having fewer postoperative complications. Specifically, in a randomized prospective study of laparoscopic versus open gastric bypass for the treatment of morbid obesity, Lujan et al¹² demonstrated that laparoscopy was a reasonable treatment offering a reduction in abdominal-wall complications and resulting in shorter hospital stays. Therefore, bariatric surgery serves as a reasonable model for the utility of laparoscopy in obese patients. It has been with similar intent that gynecologic surgeons have considered minimally invasive surgery in their obese patients, seeking reduced perioperative and postoperative complications as well as similar or improved surgical outcomes.

back to top

FEASIBILITY

Early reports of laparoscopic surgery in obese women revealed more intraoperative complications when compared to the use of a standard laparotomy incision to complete the same procedures (57% versus 16%), making obesity a relative contraindication to laparoscopy.¹³ More recently, however, investigators have compared the two surgical approaches in obese women with gynecologic disease and demonstrated more favorable results. For example, Hsu et al14 performed a retrospective study comparing surgical morbidity associated with laparoscopic management of tubal ectopic pregnancy in obese and lean women. They found no difference in mean operative time, estimated blood loss, or complication rate between the two groups. Furthermore, the authors did not find a significant difference in the conversion rates to laparotomy between the two groups. They concluded that laparoscopic management of ectopic pregnancy in the obese patient was both feasible and safe.¹⁴ Furthermore, when Holub et al15 conducted a comparative prospective study evaluating overweight women (BMI 25 to 30), moderately obese women (BMI exceeding 30), and morbidly obese women (BMI exceeding 36) undergoing laparoscopic hysterectomy for benign conditions, they found no significant differences in estimated blood loss, complication rate, conversion to laparotomy, operative time, or length of hospital stay among the three groups.¹⁵ Several other studies have supported these findings.^{16, 17}

Similar feasibility has also been demonstrated with regard to the laparoscopic approach to obese patients with gynecologic malignancies. Laparoscopic staging was first performed in the United States by Childers et al¹⁸ in 1992 in patients who were found to have endometrial carcinoma. They found the procedure to be safe and effective. Subsequently, many gynecologic oncologists began performing laparoscopic procedures on patients with endometrial cancer. One prospective study was conducted in 42 women with clinical stage I endometrial cancer and a BMI exceeding 28. These women were offered a laparoscopic hysterectomy, bilateral salpingo-oophorectomy, and node dissection if indicated. When compared with obese women who underwent laparotomy, there was no significant difference in estimated blood loss, operative time, or postoperative complications. Furthermore, women who underwent laparoscopic staging required significantly less postoperative intravenous pain medication, had more lymph nodes removed, and had shorter hospitalizations. The total cost of laparoscopic surgery when compared with laparotomy was less, but this value did not achieve statistical significance. In addition, the laparoscopy group returned to work 22 days sooner on average than the laparotomy group.¹⁹ Again, these findings suggested that minimally invasive surgery in obese gynecologic patients was not only feasible, but also potentially of greater overall benefit to the patient.

back to top

PERIOPERATIVE CONSIDERATIONS

Endotracheal intubation is required in most instances when laparoscopy is performed. For adequate pelvic visualization, it is usually necessary to place the patient in a relatively steep Trendelenburg position. This maneuver can be particularly challenging for the anesthesiologist managing the obese patient. In the Trendelenburg position, there is a cephalad displacement of the diaphragm that causes an increased peak inspiratory pressure and decreased functional residual and vital capacity. These changes lead to an increase in intrathoracic pressure and subsequent atelectasis which results in a lower partial arterial oxygen pressure and greater difficulty maintaining adequate oxygenation.⁵ Further, carbon dioxide (CO₂), which is used as the insufflating agent, is readily absorbed and raises the risk of hypercapnia in patients who are already difficult to manage while intubated.

Multiple techniques have been explored to reduce this risk of hypercapnia. One approach (the "Foley lap-lift") involves harnessing a mechanical retractor to the operative bed, with Foley catheter placement midway between the umbilicus and pubic symphysis to help elevate the anterior abdominal wall. The goal of this technique is to decrease the amount of CO₂ retention and peak airway pressures by utilizing a low-pressure pneumoperitoneum.²⁰ A second method aimed at reducing the risk of hypercapnia is gasless laparoscopy. With this technique, a mechanical retractor is fixed to the side of the operating table to elevate the anterior abdominal wall, and valveless trocars are placed to allow air exchange into the peritoneal cavity.²¹ Two devices that are used are the Abdo-lift and the Laprolift retraction system. These techniques, though both effective in decreasing the insufflation pressures, can be technically challenging and require a certain operative familiarity.

Recently, researchers have investigated the incidence of hypercapnia and risk of conversion to open laparotomy. Specifically, Fugita et al²² looked at increasing insufflation pressure to 20 mm Hg in obese patients. None of the patients in this study required open conversion secondary to hypercapnia, and the authors concluded that increasing the pressure was safe in this operative setting.²² This simple operative intervention seems to offer a reasonable alternative to pursuing the more technically difficult procedures discussed here.

back to top

PROCEDURE

Positioning

Particular care must be taken when positioning the patient on the operating table, as obese patients are at higher risk of pressure sores and neural injuries. Ulnar and lateral femoral cutaneous neuropathies have been associated with surgery in patients with an increased BMI.⁵ First, the surgeon and operating-room staff must check that the operating table can accommodate the specific weight of the patient, ensuring maximal intraoperative maneuverability. Next, it is essential that the patient be placed in the proper dorsal lithotomy position using Yellofin, PAL Pro, or Ultrafin stirrups. The Ultrafin stirrups, if available, are specifically designed for larger patients. Other steps for preventing complications secondary to positioning are placing protective padding over the wrists and elbows before tucking the arms at the patient's side, and placing shoulder braces over the acromion processes.²³ Sleds can also be used to help maintain the arms at the patient's sides (Figure 1).

Click to Enlarge

Figure 1. a) Proper padding of wrist and elbow during tucking of upper extremity along patient's side. b) Demonstration of proper use of arm sleds and shoulder braces.

Pneumoperitoneum

It is well established that creation of the pneumoperitoneum is a critical step in laparoscopy, as the majority of complications occur during initial placement of the Veress needle or the trocar.²⁴ This can be challenging when operating on obese patients, particularly when increased levels of preperitoneal fat makes it difficult to see the inferior epigastric vessels. An exhaustive review of an open-entry technique versus a blind-entry technique in laparoscopic surgery is beyond the scope of this article. However if opting for the closed technique, the surgeon must remember that correct selection and placement of the Veress needle is critical. First, access to the longer (150-mm) Veress needle should be ensured. The Veress needle should be placed perpendicular to the skin to prevent preperitoneal insufflation. In the obese patient, this may require grasping the abdomen with towel hooks or other grasping forceps to maximize proper traction (Figure 2).

Click to Enlarge

Figure 2. Schematic of proper Veress needle placement in obese patients.

If the umbilical approach to the closed entry technique fails, several other landmarks may prove useful. The first alternative entry point is Palmer's point (the site of left upper-quadrant entry), which is often used as an alternate entry point in patients with suspected adhesive disease from prior surgeries. This point is in the midclavicular line, two finger-breadths below the rib cage on the patient's left side. A specific consideration for this entry site is the fat distribution in the obese patient. Milad and Terkildsen²⁵ used a spinal needle to examine abdominal-wall thickness at both the umbilicus and Palmer's point. These authors found that the mean thickness for obese women at the umbilicus was 3.0 ± 1.2 cm, whereas the mean thickness at the left upper quadrant was 4.4 ± 1.0 cm.²⁵ Thus, the left upper-quadrant entry in patients with a significantly elevated BMI may be no less difficult than the umbilical approach. However, in a consecutive series of 600 morbidly obese patients, Schwartz et al²⁶ reported a high degree of success and only one visceral or vascular injury using Palmer's point.

Finally, before abandoning the closed-entry technique in patients with a low suspicion of pelvic adhesive disease from prior surgery, severe endometriosis, or a gynecologic malignancy, attempting abdominal insufflation by passing the Veress needle through the apex of the vagina into the posterior cul-de-sac is a viable option.²⁷ If the closed-entry technique is ultimately unsuccessful, the surgeon should not hesitate to proceed with an open-entry technique. This involves performing a minilaparotomy at the umbilicus. The skin, subcutaneous fat, fascia, and peritoneum are incised under direct visualization. A blunt trocar is then placed, and the pneumoperitoneum is created with insufflation of CO₂. In fact, this technique has been advocated by many investigators when operating on obese patients to decrease the incidence of vascular and visceral injuries.


Port Placement

After proper positioning and the achievement of pneumoperitoneum, the surgeon must safely determine port-site placement. This task can be difficult, given that the traditional landmarks used in laparoscopy cannot be utilized in obese patients, and standard insufflation pressures are often inadequate. To avoid complications related to trocar placement, the surgeon should first select trocars of adequate length and familiarity. Gynecologic surgeons at the University of Michigan use the Adapt trocar, which is nonbladed and asymmetrically dilating (Figure 3). Once the trocars are selected, some investigators advocate placement of two insufflators to maintain adequate exposure for trocar placement and optimize the pneumoperitoneum. Alternatively, other authors advocate temporarily increasing the insufflation pressure to 25 mm Hg to allow a greater distance for trocar placement, thereby decreasing the risk of vascular and visceral complications.²²

Click to Enlarge

Figure 3. Views of the Adapt trocar.

In the nonobese patient, the bifurcation of the aorta is at the umbilicus and the anterior superior iliac spine (ASIS) is 8 cm caudal to the umbilicus. However, when placing the umbilical trocar in the obese patient with a large panniculus, it is important to remember that the umbilicus is pulled downward so that it is 2.9 cm caudal to the aortic bifurcation and the ASIS is less than 8 cm caudal to the umbilicus. Thus, patients with a large panniculus are at particular risk for trocar complications, including penetration of an underlying skin fold and bladder injury. To circumvent these complications, the panniculus should be pushed cephalad until the umbilicus is 8 cm cephalad to the ASIS.²⁸ Following this step, umbilical entry can be initiated.

Once umbilical entry is secured, direct visualization can be used to place the remaining trocars after localization with a spinal needle. One point of caution is that despite adequate trocar placement, intraperitoneal exposure can be extremely limited in obese patients, as they tend to have increased levels of omental, retroperitoneal, and preperitoneal fat. In this setting, many surgeons advocate shifting trocar placement somewhat more laterally to offer better exposure and decrease the amount of torque on the abdominal musculature. This allows for enhanced visualization and more freedom of surgical movement without requiring longer instruments.²²


Trocar Site Closure

Closure of the fascia is recommended for any incision greater than 10 mm. Exposing the fascia can be particularly challenging in the obese patient. The reusable Carter-Thomason device allows for direct visualization of the closure, resulting in decreased risk for bowel strangulation and hernia development. If this device is not long enough to completely traverse the abdominal wall in the obese patient, an alternative is the disposable Endoclose device.

back to top

CONCLUSION

Traditionally, obesity has been a relative contraindication to minimally invasive surgery. However, with the growing success of minimally invasive approaches to a variety of surgical procedures—including a significant number of gynecologic techniques—surgeons have demonstrated the feasibility and safety of laparoscopy in obese patients. With proper preparation and careful consideration of surgical pitfalls of laparoscopy in the obese patient, the majority of gynecologic procedures can be completed safely and efficiently without resorting to laparotomy.

back to top

References:

1. National Heart, Lung, and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Available at: http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm. Accessed December 1, 2004.
2. Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA. 2002;288(14): 1723-1727.
3. Obesity: preventing and managing the global epidemic. Report of a WHO Consultation. Geneva, World Health Organization, 2000 (WHO Technical Report Series, No. 894).
4. Bongain A, Isnard V, Gillet JY. Obesity in obstetrics and gynaecology. Eur J Obstet Gynecol Reprod Biol. 1998;77(2): 217-228.
5. Ogunnaike BO, Jones SB, Jones DB, Provost D, Whitten CW. Anesthetic considerations for bariatric surgery. Anesth Analg. 2002;95(6):1793-1805.
6. Doucette RC, Scott JR. Comparison of laparoscopically assisted vaginal hysterectomy with abdominal and vaginal hysterectomy. J Reprod Med. 1996;41(1):1-6.
7. Scribner DR Jr, Walker JL, Johnson GA, McMeekin, DS, Gold MA, Mannel RS. Laparoscopic pelvic and paraaortic lymph node dissection in the obese. Gynecol Oncol. 2002;84(3):426-430.
8. Stanford A, Glascock JM, Eid GM, et al. Laparocopic Roux-en-Y gastric bypass in morbidly obese adolescents. J Pediatr Surg. 2003;38(3):430-433.
9. Gould JC, Needleman BJ, Ellison EC, Muscarella P, Schneider C, Melvin WS. Evolution of minimally invasive bariatric surgery. Surgery. 2002;132(4):565-571.
10. Schauer PR, Ikramuddin S. Laparoscopic surgery for morbid obesity. Surg Clin North Am. 2001;81(5):1145-1179.
11. Fried M, Peskova M. Gastric banding: advantages and complications. A 5- and 10-year follow-up. Obes Surg. 1995;5(4): 372-374.
12. Lujan JA, Frutos MD, Hernandez Q, et al. Laparoscopic versus open gastric bypass in the treatment of morbid obesity: a randomized prospective study. Ann Surg. 2004;239(4):433-437.
13. Mendoza D, Newman R, Albala D, et al. Laparoscopic complications in markedly obese urologic patients (a multi-institutional review). Urology. 1996;48(4):562-567.
14. Hsu S, Mitwally MF, Aly A, Al-Saleh M, Batt RE, Yeh J. Laparoscopic management of tubal ectopic pregnancy in obese women. Fertil Steril. 2004;81(1):198-202.
15. Holub Z, Jabor A, Kliment L, Fischlova D, Wagnerova M. Laparoscopic hysterectomy in obese women: a clinical prospective study. Eur J Obstet Gynecol Reprod Biol. 2001; 98(1):77-82.
16. Eltabbakh GH, Piver MS, Hempling RE, Recio FO. Laparoscopic surgery in obese women. Obstet Gynecol. 1999;94(5 Pt 1):704-708.
17. Kuoppala T, Tomas E, Heinonen PK. Clinical outcome and complications of laparoscopic surgery compared with traditional surgery in women with endometrial cancer. Arch Gynecol Obstet. 2004;270(1):25-30.
18. Childers JM, Brzechffa PR, Hatch KD, Surwit EA. Laparoscopically assisted surgical staging (LASS) of endometrial cancer. Gynecol Oncol. 1993;51(1):33-38.
19. Eltabbakh GH, Shamonki MI, Moody JM, Garafano LL. Hysterectomy for obese women with endometrial cancer: laparoscopy or laparotomy? Gynecol Oncol. 2000;78(3 Pt 1):329-335.
20. Stany MP, Winter WE 3rd, Dainty L, Lockrow E, Carlson JW. Laparoscopic exposure in obese high-risk patients with mechanical displacement of the abdominal wall. Obstet Gynecol. 2004;103(2):383-386.
21. Koivusalo AM, Kellokumpu I, Scheinin M, Tikkanen I, Makisalo H, Lindgren L. A comparison of gasless mechanical and conventional carbon dioxide pneumoperitoneum methods for laparoscopic cholecystectomy. Anesth Analg. 1998;86(1):153-158.
22. Fugita OE, Chan DY, Roberts WW, Kavoussi LR, Jarrett TW. Laparoscopic radical nephrectomy in obese patients: outcomes and technical considerations. Urology. 2004;63(2): 247-252.
23. Wechter ME, Advincula AA. Prevention of perioperative neuropathies. Female Patient. 2003;28(10):23-35.
24. Bateman BG, Kolp LA, Hoeger K. Complications of laparoscopy--operative and diagnostic. Fertil Steril. 1996; 66(1):30-35.
25. Milad MP, Terkildsen MF. The spinal needle test effectively measures abdominal wall thickness before cannula placement at laparoscopy. J Am Assoc Gynecol Laparosc. 2002; 9(4):514-518.
26. Schwartz ML, Drew RL, Andersen JN. Induction of pneumoperitoneum in morbidly obese patients. Obes Surg. 2003;13(4):601-604.
27. van Lith DA, van Schie KJ, Beekhuizen W, du Plessis M. Cul-de-sac insufflation: an easy alternative route for safely inducing pneumoperitoneum. Int J Gynaecol Obstet. 1980;17(4): 375-378.
28. Pelosi MA, Pelosi MA. Alignment of the umbilical axis: an effective maneuver for laparoscopic entry in the obese patient. Obstet Gynecol. 1998;92(5):869-872.

back to top