SPECIAL PROBLEMS IN LAPAROSCOPIC SURGERY

MINIMAL ACCESS SURGERY, PART I

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SPECIAL PROBLEMS IN LAPAROSCOPIC SURGERY Previous Abdominal Surgery, Obesity, and Pregnancy Myriam J. Curet, MD

The application of laparoscopic techniques to general surgical procedures has revolutionized the field of general surgery. Since the first laparoscopic cholecystectomy was performed 10 years ago, minimally invasive techniques have been applied to an increasing number and variety of surgical procedures. At first, several absolute contraindications to laparoscopy were advocated, including pregnancy, previous abdominal surgery, inability to tolerate increased abdominal pressure, bowel obstruction, coagulopathy, obesity, cirrhosis, inability to tolerate general anesthesia, choledocholithiasis, and acute cholecystitis. As surgeons gained more experience with laparoscopic techniques and technical advances in instrumentation were made, these limitations were reassessed; many became only relative contraindications. Some are no longer considered contraindications at all because, in these situations, proper planning, expert judgment, and meticulous surgical technique can prevent complications while still allowing patients to experience the benefits of minimally invasive surgery. This article deals with three specific situations that were once considered contraindications to laparoscopic procedure: (1) previous abdominal surgery, (2) obesity, and (3) pregnancy. Laparoscopy can be used safely in patients with these problems if specific strategies and tactics are used to prevent potential problems. PREVIOUS ABDOMINAL SURGERY

Originally, patients with previous abdominal surgery were recommended not to undergo laparoscopy because of the increased risk for penetrating bowel From the Department of Surgery, University of New Mexico School of Medicine; and the Minimally Invasive Surgery Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico

SURGICAL CLINICS OF NORTH AMERICA VOLUME 80 NUMBER 4 AUGUST 2000

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injury caused by needle or trocar insertion through bowel adhered to the abdominal wall. Also, laparoscopic adhesiolysis performed to gain adequate exposure to the operative field was feared to be more time-consuming and potentially more treacherous than open adhesiolysis. Finally, in combination with concerns regarding a restricted view of the operative field, these issues led many surgeons, early in their laparoscopic surgical experience, to avoid offering laparoscopic cholecystectomy to patients with biliary tract disease and previous abdominal surgery. Thirty percent to 50% of patients presenting for cholecystectomy have had previous operation~,~~, 92 and these patients should and could still benefit from laparoscopic management. Previous abdominal surgery may have no impact on a planned laparoscopic procedure, or it may have such a significant impact that the procedure cannot be completed safely. Formation and extent of adhesions are unpredictable. Previous surgery is clearly a risk factor for adhesion formation. Autopsy studies have found adhesions in 75% to 90% of patients with previous abdominal surgery, typically localized to the previous surgical site but often involving other areas.113 These studies also demonstrated adhesions in 25% of patients with no previous surgery, however. In clinical studies, 60% of patients with previous abdominal surgery undergoing laparoscopic cholecystectomy required adhesiolysis, 10% of patients with no previous abdominal surgery had adhesions in areas at risk for injury, and one third of patients with previous abdominal surgery had no adhesions.43,44, 56, 59, Iz1 Patients with previous abdominal surgery pose two specific problems: (1) obtaining safe access to the abdominal cavity to initiate the pneumoperitoneum and (2) performing a safe adhesiolysis to gain adequate exposure to the operative field. Interference with access depends strongly on the location of previous surgery. Adhesions may be right under a scar or may be further away. Some investigators have recommended preoperative sonographic mapping of adhesions to help to determine a safe site for trocar insertion.'O, 70 Initial access to the abdominal cavity is usually at the umbilicus with a blind ( e g , Veress needle) or open, blunt tip (eg., Hasson trocar) technique. Clearly, a midline incision presents a high risk for bowel adhesions under a planned umbilical trocar site; however, even scars away from the umbilicus can lead to adhesions at the umbilical site. A blind-access technique (i.e., Veress needle insertion followed by trocar insertion) has resulted in a high rate of complications, even in patients without abdominal surgical scars.l0*12, 37, 64, 68, 73, Io1 Most vascular injuries are associated with a blind-insertion technique of the first port,73whereas more than half of all bowel injuries are associated with this technique.'O, l2 The risks for bowel injury or vascular injury are even higher if the needle or trocar is blindly placed through a previous incision. Safer alternatives include placement of the needle at a site far from previous scars, such as the right upper quadrant in patients with pelvic s ~ r g e r y ?An ~,~ attempt ~ should be made to place the needle and initial trocar in a site to be used for surgery, but occasionally access must be in a remote quadrant, such as the left subcostal region for laparoscopic cholecystectomy. The chosen site should be away from scars and should avoid the inferior epigastric vessels. Placement in the midclavicular line is safest in the upper q u a d r a n t ~ In . ~ ~the lower abdomen, the trocars are best placed lateral to the epigastric vessels but sufficiently medial to prevent colonic injury.45 Another alternative is the use of an open technique (Hasson), which allows for the identification of adherent bowel with dissection of the bowel away from the abdominal wall. Many surgeons use an open technique routinely, even in patients without previous abdominal surgery, because of the decreased risk for visceral or vascular injury. These injuries are not completely eliminated by this

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technique, but their prevalence is decreased with its use.l0In addition to decreasing the rate of bowel injury, the open technique allows surgeons to promptly identify and repair any injury that may occur, thus decreasing morbidity and mortality rates.", 45, 73, lol Finally, no reports of vascular injury with the Hasson trocar technique have been described.43,73, lol Although safer, even the open techmque can be technically difficult if performed through a previous scar. Blind cutting or spreading may damage bowel adherent to the abdominal wall, and careful dissection is still necessary. Reports of insertion of a Hasson trocar in the right iliac fossa, right upper quadrant, or subxyphoid area have suggested fewer complications and easier insertion than insertion through a previous midline umbilical scar.23,37, 56, The method used is similar to a muscle spreading incision performed for appende~tomy.3~, One group of investigatorsn found that this technique increased operating time by nearly 30 minutes, which is a major concern with the use of an open technique; however, operative times decrease with experience,a and an extra 30 minutes spent to decrease the risk for bowel injury is time well spent. Alternative sites may be used for access with the open or blind-access techniques. One advantage of placing the first port in a site away from previous scars is the improved ability to see the abdominal cavity because vision is not obscured by adhesions. This allows for better assessment of location of remaining ports. Also, surgeons then have the appropriate working distance necessary to manipulate instruments." The laparoscope can be placed through the umbilical trocar after all trocars are placed under direct visualization. New optical trocars have been developed in which the laparoscope is inserted through the transparent cannula as the trocar is advanced through the abdominal wall.", lZoThese trocars theoretically allow surgeons to see the tissue layers as the trocar is inserted. Presumably, t h s technique allows surgeons to identify bowel wall before inserting the trocar into the bowel. Data regarding safety, efficacy, and advantages over the open techruque are still inconclusive. Once safe access is obtained, adequate visualization of the abdomen to insert the remaining ports and to perform the planned surgery must be obtained. If adhesions are present, they occasionally may be circumvented by angling the laparoscope around the edge of the omentum adhered to the abdominal wall or by placing the laparoscope through fenestrations of the adhered ment turn.^^, 45 Often, though, adequate visualization of the operative field requires some degree of adhesiolysis. Numerous techniques are available. Sometimes, blunt finger dissection through the initial trocar site is adequate. This technique is most easily done with the open technique before the insertion of the Hasson trocar; or the trocar and the camera can be used to bluntly dissect the scar tissue. Also, retracting adhesions carefully may separate tissue planes. Occasionally, adhesions may be too dense to separate with this type of gentle dissection. Sharp adhesiolysis is an alternative as long as caution is used not to cut adjacent bowel. The best techmque is to follow the line of tissue adherence, if possible, which results in less bleeding and less risk for injury to adjacent viscera. A traction-countertraction technique as used for open adhesiolysis is effective. Cautery may be necessary for the adhesiolysis. Cautery presents the risk for creating tissue damage beyond that which is directly cauterized. Caution should be used not to injury adjacent organs by accurately identifying the tissue to be cauterized and adjacent tissue. The initial goal of cautery is to lyse adhesions sufficiently to allow for the insertion of a second cannula, which aids in visualization, retraction, and dissection. Sometimes three trocars (one camera and two operating ports) are needed

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for adequate adhesiolysis. Placement of additional ports than those that are typically used for the planned procedure may be necessary and should be placed without hesitation. These ports may be used for retraction of tissue to allow for better visualization or to help to place adhesions on tension before lysing. Surgeons should be flexible about cannula placement. Ports should be placed as needed to accomplish the necessary adhesiolysis. The trocars needed for surgery may be inserted later. An angled laparoscope is extremely helpful in visualizing the extent of adhesions, in performing the adhesiolysis, and in maximizing access to the operative field. Moving the laparoscope to different ports improves visualization, access, and success. Lysis of all visible adhesions is unnecessary. Only adhesions that interfere with trocar placement and with performance of the intended operation should be dissected.43Additional adhesiolysis only adds to the operative time and to the risks of surgery without benefit. Once adequate adhesiolysis is complete, the area lysed should be thoroughly inspected for possible bleeding and bowel injury. If found, these complications should be treated appropriately. Small bleeding points may be controlled with pressure, pinching, clips, ties, sutures, or careful cautery.4J, 45,68 Bowel perforations often can be sutured laparoscopically; however, if concern exists about the extent of injury or adequate treatment, surgery should be converted to open laparotomy. The effect of adhesions depends on the planned laparoscopic procedure and the site of the previous surgery. For example, in patients undergoing laparoscopic cholecystectomy, previous pelvic surgery may necessitate the use of a Hasson trocar instead of a Veress needle but should not interfere with visualization of the upper abdomen. Numerous studies” 33, 64,97, lo2* 122 have attempted to identify risk factors for conversion. These studies have not always identified previous abdominal surgery as a risk. Most of these studies routinely used open access techniques and indicated that use of this technique resulted in decreased conversion rates among patients with previous abdominal surgery. Other studies have demonstrated that previous abdominal surgery, especially upper abdominal surgery, is a risk factor for increased conversion rates.48, 53. 96 Gastroduodenal surgery especially may make completion of a laparoscopic cholecystectomy difficult.92Problems may be encountered while trying to visualize the operative site,u or dissection of the biliary tree may be difficult in patients with previous duodenal surgery secondary to dense adhesions in the triangle of Calot.zWiebke et a1115found that 33% of patients whose surgeries were converted during laparoscopic cholecystectomy had undergone previous upper abdominal surgery compared with 4% of those whose surgery was completed laparoscopically. No increase in the morbidity rate occurred. Schirmer et a192compared patients with previous upper abdominal surgery with patients without prior upper abdominal operations. The former experienced longer hospitalization, higher rate of complications, and a higher conversion rate, although operative times were comparable. Schirmer et a192and Frazee et a132specifically evaluated the effects of previous intra-abdominal surgery on laparoscopic cholecystectomy. Conversion rates and mean operative times were similar among patients with previous abdominal surgery and those without prior abdominal surgery. Frazee et aP2 found that even patients with previous upper abdominal surgery did not have increased operative times or conversion rates. Wongworawat et aP1 compared patients with previous abdominal surgery who underwent laparoscopic or open cholecystectomy. Operative times were similar among the two groups of patients. The conversion rate was only 4.4%, but conversion was necessary in 71% of these patients because adhesions prevented safe placement of trocars. In all three

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studies, patients with previous abdominal surgery experienced the advantages of minimally invasive surgery, including a hospital stay of approximately 2 days and no increase in mortality or complication rate except for wound infections in the study by Schirmer et a1.92 Previous abdominal surgery is not a contraindication to attempting a procedure laparoscopically. Patients should be warned of the increased risk for bowel injury, the possible need for additional trocars, and the increased risk for conversion. Preoperative planning by surgeons is important to minimize risks to patients and to maximize successful completion of planned surgery. Adequate preparation includes assessing the geographic relationship between the proposed surgery and the abdominal scar, making an initial entry at a distance from obvious scars, and the use of the open technique for access and careful adhesiolysis. Also, surgeons should be sufficiently experienced in less complicated cases before attempting laparoscopy in patients who may have extensive adhesions. OBESITY

General surgeons performing laparoscopic cholecystectomiesevaluate many obese patients presenting for treatment of biliary tract disease. Obesity affects 26% of the adult population in the United States,I4and obese patients are at high risk for gallstones. Gallstones occur in 30% to 35% of obese patient^,'^,^, Io8, so not surprisingly, as many as 25% of patients presenting for laparoscopic cholecystectomy are morbidly obese.8oInitially, laparoscopy was contraindicated in obese patients primarily because of technical difficulties encountered whle performing the procedure, such as access, trocar insertion, cannula displacement, and obtaining a pneumoperitoneum.8l A secondary concern was that obese patients might have higher morbidity and mortality rates when undergoing surgery compared with nonobese patients. Several physiologic changes that occur in obese patients were believed to lead to the increased risks. Obese patients have an increased intravascular volume and cardiac output, and a decreased total peripheral resistance, resulting in left ventricular hypertr~phy.'~, 25 These findings, coupled with the high incidence of hypertension in these pa25, 76 Pulmonary changes tients, may lead to increased cardiovascular rn~rbidity.'~, include a decreased functional residual capacity, compliance, and PaO, leading to increased work of breathing.'" 25, 76 Postoperative pulmonary complications, such as atelectasis, are more common in obese patients.'" 76 Also, obese patients commonly have ventilation-perfusion defects that are worsened by general anesthesia, which can also compromise postoperative pulmonary function?6 Coagulation abnormalities, increased fatty acid levels, and difficulty with postoperative mobilization all may contribute to an increased risk for deep vein thrombosis and pulmonary embolus.14,15, 25 Numerous studies'4,76, 79, 'lo have shown an increased prevalence of infectious complications and wound healing problems in obese patients. As many as 35% of obese patients undergoing surgery may experience wound healing Aside from wound healing complications, most of the other risks are only potential, and the actual risks of elective abdominal surgery in obese patients probably are not prohibitive.'" 76 One study79evaluating open cholecystectomy in obese patients showed a similar prevalence of perioperative complications in obese and nonobese patients except for infectious ones. No increase in the surgical mortality rate has been noted 43* 76 among obese patients.I4* Despite the lack of hard data substantiating an increased surgical morbidity rate among obese patients, certain precautions are advisable when performing

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laparoscopicsurgery in this group of patients. A preoperative cardiac assessment with an ECG is rec~mmended.'~, 76 Patients may require more extensive workup if symptoms warrant it. Preoperative cessation of smoking and some attempt at preoperative weight loss help to decrease operative morbidity, even if the weight loss is minimal.76Prophylaxis against thromboembolic complications should be used before the induction of general anesthesia. Compression stockings, lowdose heparin, or both commonly are used. Preoperative administration of appropriate prophylactic antibiotics is i m p ~ r t a n t Surgical .~~ maneuvers to decrease surgical morbidity include proper positioning of morbidly obese patients on an 43 Pressure points should be adequately appropriate bed that can support them.25* padded. A footboard and a safety strap should be in place before surgery. Early ambulation and aggressive pulmonary toilet postoperatively may help to diminish pulmonary and thromboembolic complications. One of the major technical problems encountered in obese patients is access to the abdominal cavity, which is especially difficult with the needle-insertion technique. Because of the thickness of the abdominal wall and the preperitoneal fat, accurate assessment of the location of the tip of the needle is difficult, 87* "' The umbilicus is the thinnest making preperitoneal insufflation area of the abdominal wall, and needle insertion at this point is probably 91 The skin incision should be made deep in the umbilicus, where the distance from skin to fascia is shortest.81Also, successful insertion may be more likely to be successful with a 90" insertion angle instead of the usual 45°.43,62 This modification may result in a higher risk of vascular injury, however. Once the needle is inserted, the saline drop test and confirmation of an initial low intra-abdominal pressure are crucial in confirming proper intra-abdominal placement. If any concerns exist about proper positioning, the needle should be removed. Surgeons may need to attempt insertion numerous times before success is achieved.62Occasionally an extralong Veress needle may be Alternate blind-insertion sites, such as the left upper quadrant, right upper quadrant, transvaginal, or transuterine route, may be used if needle insertion at the umbilicus is unsuccessful.=, Most techniques of Veress needle insertion require lifting the abdominal wall by grasping the skin with towel clips or by grasping the abdominal wall manuallys1The former may lengthen the abdominal wall by pulling the skin away from the fascia. Another modification of the Veress needle insertion is to carry the skin incision down to the fascia, which is then grasped and elevated before insertion of the needle."' This maneuver eliminates passage of the needle through subcutaneous tissue and shortens the distance to the peritoneal cavity, thus decreasing the risk for preperitoneal insufflation and improving the likelihood of successful placement. Another alternative is the use of the open insertion technique with a Hasson trocar. Controversy exists over the advantages and disadvantages of this access technique compared with a closed technique in obese patients. Some investigators believe that a large skin incision is necessary for Hasson trocar insertion in obese patients, leading to perioperative leakage of gas and to increased rates of wound infection postoperatively.= Other investigators believe that the open insertion technique is successful and, as surgeons gain experience, can be performed in a timely fashion with minimal morbidity.43Nuzzo et a173found that insertion of a Hasson trocar in obese patients required significantly more time to perform than in nonobese patients by up to approximately 1 minute. They also found that this difference disappeared as surgeon experience increased. Several studies have looked at the use of abdominal wall-lifting devices in obese patients.O The concerns about adequate exposure and increased abdominal

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wall pain that occur in nonobese patients are magnified in obese patients. At present, no indications exist that an abdominal wall-lifting device is better than a standard pneumoperitoneum for laparoscopic surgery in obese patients. Significant disadvantages may exist, especially in terms of adequate exposure.43 One additional factor that influences successful access is the location of the umbilicus. In patients with a large pannus, the umbilicus can be caudal, sometimes even in a suprapubic p0sition.4~The camera port must be closer to the upper abdomen for adequate visualization of the operative field, so a supraumbilical site may be more advantageo~s.~~ The laparoscope should be used to measure the distance from the xyphoid to determine the optimal location of the incision. Insertion of the remaining ports is performed under direct visualization as usual. Surgeons should angle the ports toward the operative site.15,87* If not, a great deal of torque may need to be applied to the trocars, whch may make insertion of instruments difficult, may lead to bending or breaking of the cannulas, or may result in significant gas The increased force applied on the abdominal wall to torque the trocars may be transmitted to tissue, causing injury.87Proper placement of ports, which may be different than in nonobese patients, helps to prevent inadvertent problems.87Slippage of the trocars out of the abdominal cavity is a common and frustrating event leading to subcutaneous emphysema and prolonged operative time.15, Cannulas can be sutured to the abdominal wall to prevent this problem. Some trocars come with built-in threads that can help to stabilize them. Occasionally, extra-long trocars are necessary to prevent slippage of the trocars out of the abdominal cavity; however, the operation usually can be performed with standard-length 69, 91 cannulas.43* Once intra-abdominal access is obtained and a pneumoperitoneum established, the next critical step is to obtain adequate exposure. Tilting the bed, often steeply, may help to displace intra-abdominal 0rgans.2~. 91, I1O Some investigators have advocated increasing intra-abdominal pressure from 15 mm Hg to 20 mm Hg,9I, suggesting that this helps to elevate the heavy abdominal wall, thus improving visualization and maintaining adequate working space; however, this may result in decreased venous return, decreased cardiac output, and hypotension, especially in patients with underlying cardiovascular c0mpromise.2~If a patient experiences hemodynamic changes, the intra-abdominal pressure should be decreased immediately. Surgeons should have the abdominal wall completely relaxed, which helps to keep the abdominal wall adequately elevated at lower intra-abdominal pressures.25Muscle relaxants should be titrated to the individual patient. Use of the angled scope can be critically important.8O The angled scope allows surgeons to look over the large omentum and colon or around a fatty falciform ligament.43,91 Also, insertion of additional ports may be ne~essary.'~, 91 Instruments inserted through a trocar in the right lower quadrant can be used to retract a heavy omentum downward to improve exposure for a laparoscopic cholecystectomy. Or, during a laparoscopic cholecystectomy, a liver retractor inserted through a trocar in the left upper quadrant may be necessary because the fatty liver often seen in obese patients can be hard to retract and can obscure the triangle of Ca10t.~~ To some extent, the distribution of fat determines the success rate of laparoscopy in obese patients. A patient's total weight is not as important as the fat 45 For example, short, obese patients present more difficulty than di~tribution.4~f do tall, obese patients.62Some patients have a thick abdominal wall, interfering with successful access, but relatively normal intra-abdominal fat, which does not complicate exposure. Other patients have a thinner middle abdominal wall with fat localized more laterally, with a heavy omentum and an obscured

triangle of Calot. Schrenk et a196found that obesity was associated with increased difficulty in visualizing the triangle of Calot but did not lead to increased conversion rates. Obesity has been considered a risk factor for increased conversion rates in several studies.33,48* 98 This finding is not uniform, however. Many investigators have performed laparoscopic surgery on obese patients with conversion rates similar to those seen in nonobese patients2,5, 32, 69, loZ,115 These low conversion rates may be a consequence of patient selection. Early in their operative experience, surgeons did not offer laparoscopic cholecystectomy to obese patients. As surgical experience increased, conversion rates decreased. At this point, obese patients were offered laparoscopic cholecystectomy, with the benefits of surgeon experience and lower conversion rates. Numerous studies evaluating laparoscopic cholecystectomy in obese patients have been published." 15, 32, 69, 80, 91, 97, I1O Several, but not all, have demonstrated increased operative times when comparing obese with nonobese pat i e n t ~ .In ~ ~ general, conversion rates, length of stay, and mortality and complication rates, excluding infectious ones, were not significantly different among obese and nonobese patients. One study found that nonsurgical anesthetic complications were more common in obese and morbidly obese patients compared with the nonobese group, but no difference in the mortality rate was found? These studies demonstrate that obese patients can undergo laparoscopic surgery safely. Some investigators have suggested that this is a better approach in obese patients than open laparotomy because of better exposure, less postoperative pain, less postoperative pulmonary complications, and less postoperative wound infections.5,15. 32. 69.80.91, 110

PREGNANCY

As with previous abdominal surgery and obesity, pregnancy initially was considered an absolute contraindication to laparoscopic cholecystectomy. Although several potential advantages existed to minimally invasive surgery that pregnant patients could experience, persistent questions about the effects of a carbon dioxide pneumoperitoneum on the mother and fetus prevented application of this technique to this patient population. Specifically, concerns centered around the effects of increased intra-abdominal pressure on venous return, cardiac output, and uterine blood flow, with possible resulting maternal and fetal acidosis. Significant experience with laparoscopy in pregnant patients to rule out ectopic pregnancy exists in the gynecology literature.58,90, lo9 Most of these patients had normal intrauterine pregnancies. They tolerated the laparoscopic surgery well, without an increase in fetal loss or adverse long-term outcome regardless of the trimester in which laparoscopy was performed.65,90, These results, and the clear advantages of minimally invasive surgery compared with open laparotomy, led surgeons to begin offering laparoscopic cholecystectomy and appendectomy to pregnant patients in 1991.6.84, 112 Approximately 0.2% of pregnant patients require intra-abdominal general surgery during their pregnancies.z6, 54, 65 During the first trimester of pregnancy, the major risks are secondary to teratogenesis and a miscarriage rate of 12%.* During the third trimester, a 30% rate of preterm labor and premature delivery *References 16, 19, 24, 26, 30, 57, 65, 66, 71, 104, and 117

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exists and increases with increasing gestational age.'6, 39, 44, 57, Also, the gravid uterus in the third trimester can interfere with adequate visualization of the abdominal cavity and the operative field.'" 18, 44 In the second trimester, the rate of miscarriage is 0%, the rate of preterm labor is only 5% to 8%, no risk of 44, 57, teratogenesis exists, and the gravid uterus does not create an ffi, 66 For these reasons, the second trimester is considered the safest time for surgery in pregnant patients.38,89 The most common problem that surgeons encounter in pregnant patients is 55, 66, 94 The acute appendicitis, which occurs in 0.05% to 0.1% of pregnan~ies?~, prevalence is evenly distributed throughout all trimesters. Accurate diagnosis of acute appendicitis is more difficult in pregnant patients than in nonpregnant patients because the usual clinical signs of appendicitis, such as leukocytosis, nausea, vomiting, and abdominal pain, are already present in the third trimester and therefore 54* 58* 94 Also, the change in location of the appendix with increasing gestational age confuses the diagnosis, leading to a correct preoperative diagnosis rate of only 50% in the third trimesteP5,58, 94, Io9 compared with 85% in nonpregnant patients. Delay in diagnosis and treatment leads to an increased perforation rate, which increases fetal morbidity and mortality rates. Preterm labor and premature delivery rates can be as high as 40% in patients with perforated appendiciti~.5~? 55, 94 The fetal mortality rate, which is less than 5% in cases of uncomplicated acute appendicitis, increases to nearly 30% when treatment is delayed until after perforation.42,54, 55, 94 Pregnant patients with suspected acute appendicitis should be explored immediately after appropriate resuscitation regardless of gestational age. Decisions regarding open versus laparoscopic approach are discussed later in this article. Biliary tract disease is the second most common general surgical problem encountered during pregnancy. Gallstones are present in nearly 5% of the pregnant population34,39* 41* 55 and often are symptomatic. Most patients with biliary colic can be managed conservatively with a nonfat diet and pain medication until the postpartum period; however, conservative management is associated with a high recurrence rate. Nearly half of patients require repeat hospitalizations.) Also, several investigators have found a higher incidence of spontaneous abortion, preterm labor, or premature delivery in patients treated with nonoperative therapy than those undergoing cholecystectomy8< 24, 39* Io6 A cholecystectomy is required in approximately 0.05% of all pregnanciest and in 40% of pregnant patients with symptomatic biliary tract disease.24,38, 41, 66, 118 An uncomplicated open cholecystedomy is associated with a 0.1% maternal mortality rate, a 5% prevalence of fetal death, and a 7% prevalence of preterm labor and premature delivery.$ Complications, such as gallstone pancreatitis or acute cholecystitis, can increase the maternal mortality rate to 15% and fetal demise to 6O%.§ Indications for cholecystectomy in pregnant patients include repeated attacks, acute cholecystitis, persistent vomiting, and gallstone pancreatitis. If operative therapy is necessary before delivery, the second trimester is best, if at all possible.'" 38, 40,57, 71, 89, 103 Once a decision for surgical therapy in pregnant patients is made, the surgical approach must be considered. Concerns regarding the deleterious effects of laparoscopic surgery on the mother and fetus include possible maternal hemodynamic changes and instability secondary to decreased venous return and *References 8, 16, 22, 24, 30, 38, 39, 40, 57, 66, 103, and 106. tReferences 16, 39, 41, 54, 55, 57, 66, 71, 103, and 106. $References 18, 38, 39, 54, 55, 66, 83, 103, and 117. §References 24, 30, 38, 41, 54, 83, 103, 106, 107, and 117.

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cardiac output.2y,50, 67. 72, Also, an increase in intra-abdominal pressure may lead to decreased uterine blood flow and increased intrauterine pressure. All of these changes could result in fetal hypoxia.6,lx, 20, 82, x9, Io9, The acidosis experienced in patients undergoing a carbon dioxide pneumoperitoneum could be potentiated in the fetus, leading to respiratory acidosis in mother and fehs.7,

18, 2Y, 31. 50, 72, 82, 89, 104

Studies evaluating the effects of carbon dioxide pneumoperitoneum in pregnant baboons and sheep have demonstrated fetal tachycardia, fetal hypertension, and severe maternal and fetal acid~sis.~, 19, 20, 47, 85 Typically, fetal pH is slightly lower than maternal pH is, even when maternal pH is normal.I6,20, 47, Io4 In these animal studies, creation of a carbon dioxide pneumoperitoneum resulted in a fetal acidosis that was significantly more severe than the maternal acidosis and that was not completely corrected by maternal hyperventilation. In pregnant ewes, increased intrauterine pressure resulted from the increased intra-abdominal pressure, and uterine blood flow diminished by as much as 40Y0.'~.2o This decrease can be potentiated by hyperventilation.'y,Io5 One fetus each in studies by Hunter et a147and Reedy et alx5was unstable during the pneumoperitoneum. Despite these intraoperative changes, one study investigating the long-term effects of a carbon dioxide pneumoperitoneum found that all ewes delivered full-term, healthy lambs, suggesting that short-term fetal acidosis, even if severe, may not lead to long-term deleterious effects.20Interestingly, animal studies using nitrous oxide as an insufflating gas instead of carbon dioxide found that no fetal or maternal acidosis Lower prevalences of fetal tachycardia and hypertension were found with nitrous oxide than with carbon dioxide. These findings suggest that the use of an alternate insufflating gas may be safer in pregnant patients than in nonpregnant patients. Potential advantages of a minimally invasive approach exist for pregnant patients requiring surgery. The major advantages of laparoscopic surgery are earlier return of gastrointestinal function, earlier ambulation, decreased hospital stay, and quicker return to routine activity?', 71, Laparoscopy may also be associated with lower rates of wound infection and hernias, less pain, and less narcotic use compared with patients undergoing laparotomy.* One potential advantage of laparoscopic surgery in pregnant patients is that laparoscopy results in less manipulation of the uterus while obtaining adequate exposure, which could lead to decreased uterine irritability and decreased preterm labor, premature delivery, or spontaneous abortion.', 9, 21, 40, 41, 58, Diagnostic laparoscopy followed by laparoscopic therapeutic management could decrease delays in diagnosis or treatment and could decrease laparotomy rates.19,42, Io9 Surgeons first offered laparoscopic appendectomy and cholecystectomy to pregnant patients in 19916,w, because of these potential advantages. By the end of June 1999,46 reports of 202 laparoscopic cholecystectomiest and 9 reports of 27 laparoscopic appendectomies$ with adequate data were identified in the English language literature through a Medline search. One additional report discusses 12 laparoscopic procedures, including cholecystectomies, appendectomies, and adnexal surgery, without correlating data with specific surgery.17Most of the 202 laparoscopic cholecystectomies occurred in the second trimester,130 with 28 in the first and 24 in the third. In 22 patients, gestational age was not given. Most cases used a Hasson trocar (Endolap, Orlando, FL) for whereas a Veress "References 6, 16, 18, 21, 27, 29, 39, 40, 41, 58, 71, 84, 89, 104, and 109. tReferences 1, 3, 4, 6, 8, 9, 13, 16, 18, 21, 22, 27, 28, 30, 34-36, 3942, 46, 49, 51, 52, 57, 58, 60, 63, 71, 74, 75, 78, 82, 84, 88, 93, 99, 100, 104, 105, 109, 112, and 116118. $References 3, 36, 42, 58, 82, 94, 95, and 109.

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needle (Endolap, Orlando, FL) was used in 56 patients. An optical trocar was used in one patient, and one had gasless 5s Access method was not described for 58 patients. Operative times were available for 134 laparoscopic cholecystectomies in 24 series and ranged from 30 to 106 minutes (mean, 66 min). Intraoperative pressure was maintained between 6 mm Hg and 15 mm Hg in all series in which these data were available. Length of stay ranged from 1to 7 days (mean, 1.8d). Two studies retrospectively compared pregnant women undergoing laparoscopy with pregnant women undergoing laparotomy?,21 Patients in the laparoscopy group resumed a regular diet earlier, required less pain medication, and were discharged sooner.*' These differences were statistically significant. Patients in the laparotomy group had a higher rate of preterm labor.s One article noted a maternal-fetal death 15 days after a laparoscopic cholecystectomy performed at 20 weeks' gestation, caused by intra-abdominal hemorrhage? No other cases of maternal complications or deaths or intraoperative fetal deaths or complications have been reported. A total of 166 infants* had been delivered by the time of publication of the individual studies. Five were premature,", 39, 71,w,'09 one had hyaline membrane disease,I6 and the remaining were healthy infants delivered at full term. An additional 5 patients experienced preterm labor, which was controlled before term delivery?, zz* 2s* 4o A total of six fetal deaths have been reported, including the previously described maternalfetal death.', 3, 8, 52 One series3reported 3 patients that experienced fetal loss from a series of 4 patients undergoing laparoscopic cholecystectomy. The gestational age at the time of surgery ranged from 12 to 15 weeks? The causes of fetal death are unknown. The operative times for these 4 patients averaged 106 minutes compared with 55 minutes for the other patients in the study, and the prolonged operative times may have contributed to the deaths. One patient had a perforated appendix, and three had gallstone pancreatitis. The authors speculate that fetal loss may have been caused by the disease process rather than the laparoscopy. In another one fetal death occurred 9 weeks after laparoscopic cholecystectomy was performed in the second trimester of pregnancy. The final fetal death occurred in a woman who underwent laparoscopic cholecystectomy in the 16th week of gestation, had a bowel resection for obstruction 4 weeks later, then delivered an immature infant at 24 weeks' gestation.' A review of the laparoscopic appendectomy cases reveals that most were performed in the second trimester," with 10 in the first, 3 in the third, and 3 of unknown gestational age. Most cases used a Hasson trocar,12 with six Veress needle insertions and nine unknown. Intra-abdominal pressure was maintained between 10 mm Hg and 15 mm Hg. Operative time was available for 11 patients in four series and ranged from 30 to 70 minutes (mean, 57 min). Length of stay was prolonged at 3.8 days, but t h s was skewed by one series of six patients One uterine puncture,95one fetal death: who were kept for 11 days on a~erage.9~ one case of preterm one premature delivery,lWand 17 full-term bifthst of healthy infants occurred. The fetal loss occurred in the series by Amos et a1,T and additional data regarding cause of death are unavailable. An additional 266 pregnant patients underwent laparoscopic cholecystectomy or laparoscopic appendectomy and were discussed in an articles6 that presented the results of a survey sent to members of the Society of Laparoendoscopic Surgeons regarding their experiences with laparoscopic procedures in pregnant patients. Two spontaneous abortions occurred among the 199 patients *References 1, 3, 4, 6, 8, 9, 13, 16, 18, 21, 22, 27, 28, 30, 34-36, 39-42, 46, 49, 51, 52, 57, 58, 60, 65, 71, 74, 75, 82, 84, 88, 95, 99, 100, 104, 105, 109, 112, and 116-118. tReferences 3, 36, 42, 58, 82, 94, 95, and 109.

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who underwent laparoscopic cholecystectomy. Among the 67 patients undergoing laparoscopic appendectomy, 1patient developed preterm labor and 1 patient underwent spontaneous abortion. All spontaneous abortions occurred in patients who had surgery in the first trimester. Additional information on when or why these fetal deaths occurred is unavailable. A 2% to 5% fetal death rate, as demonstrated in the study by Reedy et als6 and calculated from published reports, compares favorably with the 5% fetal mortality rate seen with open cholecystectomies.', 24, 44, 55, 66, 83, '03 Graham et a14' reviewed the literature on laparoscopic cholecystectomy in pregnancy to correlate adverse outcome with gestational age at surgery. They found that, in all three trimesters, the rates of spontaneous abortion or premature delivery were equal to or less than those seen with open cholecystectomy for the same trimester. These data suggest that laparoscopic cholecystectomy or appendectomy is safe in all three trimesters of pregnancy, with no increase in fetal morbidity or mortality rate. Several guidelines should be followed when performing laparoscopic surgery in pregnant patients to ensure the safety of the mother and f e t ~ s . 8A~left lateral position should be used as in open surgery to prevent uterine compression of the inferior vena cava. Minimizing the degree of reverse Trendelenburg position and keeping intra-abdominal pressure low may reduce possible decreased venous return.'s*57, 71, '05 Prophylaxis against deep venous thrombosis should be used. Stasis of blood in the lower extremities is common during pregnancy, and level of fibrinogen, factor VII, and factor XI1 are increased during pregnancy, leading to an increased risk for thromboembolic events.*',71 Laparoscopy and a reverse Trendelenburg position also may increase the rate of postoperative venous thrombosis. Prophylactic antibiotics should be administered as appropriate. Pregnant patients pose special anesthetic Caution should be used to avoid aspiration, hypotension, caval compression, hypercarbia, or hypocarbia. The use of sedatives and nitrous oxide should be avoided. Changes in patient position should be gradual to avoid hypotension. One series'8 reported the use of an epidermal anesthetic in a pregnant patient undergoing laparoscopic cholecystectomy and suggested that this may be a safer anesthetic technique. An open Hasson technique for abdominal access is a safer option in pregnant patients compared with blind needle insertion. Several investigators have used a closed percutaneous route without complications, although uterine and intestinal perforation have been reported&,89, 95 and are more likely with increasing age. Insertion of the Veress needle in the subcostal area is less likely to cause uterine injury,', 13, 42, 58, but the risk for bowel injury is more likely with increasing gestational age as the uterus pushes the bowel into the upper abdomen. An alternative technique is the use of an abdominal wall-lifting device instead of a pneumoperitoneum or with low pressure (5 mm Hg).27,49 These patients still experience the benefits of minimally invasive surgery but avoid the potentially deleterious effects of a carbon dioxide pneumoperitoneum. Potential disadvantages include diminished intra-abdominal space, impaired visualization of the operative field, and significant retraction pain.41Another potential technique is the use of an optical trocar, which allows surgeons to see tissue planes and intra-abdominal organs as the trocar is Trocar placement for laparoscopic biliary tract surgery or appendectomy should not differ significantly from the positions used in nonpregnant patients in early pregnancy. As the uterus expands superior to the umbilicus, it interferes with access and visualization. The bowel is displaced into the upper abdomen, further impeding visualization. The camera port must be placed superior to the umbilicus so a supraumbilical location is more common. The laparoscope should

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then be inserted and the remaining trocars placed under direct visualization in the optimal positions. For a laparoscopic cholecystectomy, the trocars move more cephalad, closer to the costal margin with increasing gestational age. In pregnant patients with suspected acute appendicitis, the initial port can be placed in the subxyphoid area. Caution should be used to avoid insertion into the falciform ligament. Once the appendix is located, the remaining ports can be inserted in the optimal positions. Usually, one trocar in the right upper quadrant at the costal margin and a second trocar in the right lower quadrant, or just superior to the uterus, are sufficient. If the size of the uterus interferes with successful performance of a laparoscopic appendectomy, or if another cause of symptoms that cannot be managed laparoscopically is encountered, the laparoscope can help to determine the best location for an open incision. Surgeons should monitor end-tidal carbon dioxide continuously, mainPrompt taining it between 25 mm and 33 mm by changing minute ventilati~n.'~~ correction of maternal respiratory acidosis is critical because the fetus is typically slightly more acidotic than the mother is, so mild maternal acidosis may lead to severe fetal acidosis.'6*2a, 47, Controversy exists over whether Paco2 should be measured routinely with blood gases in pregnant patients undergoing laparoscopy+7,89, Hunter et a147found that in pregnant ewes, end-tidal carbon dioxide was 15 nun Hg lower than Paco2measurements at steady state and the difference worsened as Paco2increased. Corrections in Paco2were not reflected in changes in end-tidal carbon dioxide values for 30 to 40 minutes. In nonpregnant patients undergoing laparoscopic cholecystectomy, Wittgen et aP9 found that end-tidal carbon dioxide was lower than and changed more slowly than Paco2. On the other hand, Pucci and Seeds4measured blood gasses in a pregnant patient who underwent a laparoscopic cholecystectomy during the third trimester and found no change in Paco2 or arterial pH. Curet et alz0found good correlation between Paco2 and end-tidal carbon dioxide in pregnant ewes undergoing 60 minutes of a carbon dioxide pneumoperitoneum at 15 mm HgZaPaco2increases with longer duration of a carbon dioxide pneumoperitoneum, so surgeons should minimize operative times whenever possible.', Another area of controversy is perioperative fetal monitoring. Some investigators recommend preoperative and postoperative monitoring only, rather than intraoperative monitoring.39,'05* 'I8 Others recommend postoperative monitoring only in patients in the late second trimester or third trimester, when the fetus is viable?' Some investigators recommend intraoperative monitoring,*',71 even in nonviable fetuses, so that if fetal distress develops, the pneumoperitoneum can be desufflated in an effort to correct the problem.2aTransvaginal monitoring is more effective than transabdominal monitoring because it can be obtained without interfering with the operative field, and the signal is not lost when a pneumoperitoneum is established.21,41 An angled scope greatly facilitates viewing over or around the uterus. Caution should be used to minimize manipulation of the uterus. Intra-abdominal pressure should be as low as possible while adequate visualization is still achieved. A pressure of 10 mm Hg to 12 mm Hg meets these ~riteria.8~ Increased intra-abdominal pressure may decrease venous return, may potentiate fetal acidosis, may decrease uterine blood flow, and may have a direct effect on the fetus.21,105The pressure should not be more than 15 mm Hg until questions about the effects of a high intra-abdominal pressure on the fetus are answered.86 If intraoperative cholangiography is necessary, the fetus should be protected with a lead shield. Tocolytic agents should not be administered prophylactically but are appropriate if evidence because of the high risk for side 21, 57 shows uterine irritability or contractions.16,

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Numerous clinical reports demonstrate that pregnant patients can safely undergo laparoscopic surgery in any trimester, with no increase in maternal or fetal morbidity or mortality compared with open surgery. The advantages of minimally invasive surgery, such as shorter hospitalization, earlier ambulation, a n d less narcotic use, apply t o pregnant patients. Animal studies indicate possible perioperative deleterious effects, including maternal and fetal respiratory acidosis, but no long-term consequences. It may be safer and necessary to consider an alternative t o carbon dioxide pneumoperitoneum t o have pregnant patients experience the benefits of laparoscopic surgery while decreasing the potential for complications. SUMMARY

Previous surgery, obesity, and pregnancy should no longer be considered contraindications t o laparoscopic surgery. Surgeons should exercise good judgement i n patient selection, use meticulous surgical techniques, and prepare thoroughly for the planned procedure. Patients and surgeons should be aware of increased conversion rates. With these caveats in mind, these patients c a n still experience the advantages of minimally invasive surgery without increased risks. References 1. Abuabara SF, Gross GWW, Sirinek KR Laparoscopic cholecystectomy during pregnancy is safe for both mother and fetus. J Gastrointest Surg 1:48, 1997 2. Alponat A, Kum CK, Koh BC, et al: Predictive factors for conversion of laparoscopic cholecystectomy. World J Surg 21:629, 1997 3. Amos JD, Schorr SJ, Norman PF, et al: Laparoscopic surgery during pregnancy. Am J Surg 171:435, 1996 4. Andreoli M, Sayegh SK, Hoefer R, et al: Laparoscopic cholecystectomy for recurrent gallstone pancreatitis during pregnancy. South Med J 89:1114, 1996 5. Angrisani L, Lorenzo M, De Palma G, et al: Laparoscopic cholecystectomy in obese patients compared with nonobese patients. Surg Laparosc Endosc 5:197, 1995 6. Arvidsson D, Gerdin E: Laparoscopic cholecystectomy during pregnancy. Surg Laparosc Endosc 1:193, 1991 7. Barnard JM, Chaffin D, Droste S, et al: Fetal response to carbon dioxide pneumoperitoneum in the pregnant ewe. Obstet Gynecol85:669, 1995 8. Barone JE, Bears S, Chen S, et al: Outcome study of cholecystectomy during pregnancy. Am J Surg 177233, 1999 9. Bennett TL, Estes N: Laparoscopic cholecystectomy in the second trimester of pregnancy: A case report. J Reprod Med 382333, 1993 10. Borzellino G, De Manzoni G, Ricci F: Detection of abdominal adhesions in laparoscopic surgery: A controlled study of 130 cases. Surg Laparosc Endosc 8:273, 1998 11. Caprini JA, Arcelus JA, Swanson J, et al: The ultrasonic localization of abdominal wall adhesions. Surg Endosc 9283, 1995 12. Champault G, Cazacu F, Taffinder N: Serious trocar accidents in laparoscopic surgery: A French survey of 103,852 operations. Surg Laparosc Endosc 6:367, 1996 13. Chandra M, Shapiro SJ, Gordon LA: Laparoscopic cholecystectomy in the first trimester of pregnancy. Surg Laparosc Endosc 468, 1994 14. Choban PS, Flancbaum L: The impact of obesity on surgical outcomes: A review. J Am Coll Surg 185:593, 1997 15. Collet D, Edye M, Magne E, et al: Laparoscopic cholecystectomy in the obese patient. Surg Endosc 6:186, 1992

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16. Comitalo JB, Lynch D: Laparoscopic cholecystectomy in the pregnant patient. Surg Laparosc Endosc 4268, 1994 17. Conron RW, Abbruzzi K, Cochrane SO, et al: Laparoscopic procedures in pregnancy. Am Surg 65:259, 1999 18. Constantino GN, Vincent GJ, Mukalian GG, et al: Laparoscopic cholecystectomy in pregnancy. J Laparoendosc Surg 4:161, 1994 19. Cruz AM, Southerland LC, Duke T, et al: Intraabdominal carbon dioxide insufflation in the pregnant ewe: Uterine blood flow, intraamniotic pressure and cardiopulmonary effects. Anesthesiology 85:1395, 1996 20. Curet MJ, Vogt DM, Schob 0, et al: Effects of CO, pneumoperitoneum in pregnant ewes. J Surg Res 63:339, 1996 21. Curet-MJ, Xllen D, Josloff RK, et al: Laparoscopy during pregnancy. Arch Surg 131:546, 1996 22. Davis A, Katz VL, Cox R Gallbladder disease in pregnancy. J Reprod Med 40:759,1995 23. Diez J, Delbene R, Ferreres A: The feasibility of laparoscopic cholecystectomy in patients with previous abdominal surgery. HPB Surg 10:353, 1998 24. Dixon NP, Faddis DM, Silberman H: Aggressive management of cholecystitis during pregnancy. Am J Surg 154:292, 1987 25. Doherty C Special problems: Massive obesity. In Scott-Conner CEH (ed): The SAGES Manual: Fundamentals of Laparoscopy and GI Endoscopy. New York, Springer, 1999, P 95 26. Duncan PG, Pope WDB, Cohen MM, et al: Fetal risk of anesthesia and surgery during pregnancy. Anesthesiology 64790, 1986 27. Edelman D S Alternative laparoscopic technique for cholecystectomy during pregnancy. Surg Endosc 8:794, 1994 28. Eichenberg BJ, Vanderlinden J, Miguel C, et al: Laparoscopic cholecystectomy in the third trimester of pregnancy. Am Surg 623374, 1996 29. El-Minawi MF, Wahbi 0, El-Bagouri ES, et al: Physiologic changes during CO, and N,O pneumoperitoneum in diagnostic laparoscopy. J Reprod Med 26:338, 1981 30. Elerding S C Laparoscopic cholecystectomy in pregnancy. Am J Surg 165:625, 1993 31. Fitzgerald SD, Andrus CH, Baudendistel LJ, et al: Hypercarbia during carbon dioxide pneumoperitoneum. Am J Surg 163:186, 1992 32. Frazee RC, Roberts JW, Symmonds R: What are the contraindications for laparoscopic cholecystectomy? Am J Surg 164:491, 1992 33. Fried GM, Barkun JS, Sigman HH, et al: Factors determining conversion to laparotomy in patients undergoing laparoscopic cholecystectomy. Am J Surg 167:35, 1994 34. Friedman RL, Friedman IH: Acute cholecystitis with calculous biliary duct obstruction in the gravid patient: Management by ERCP, papillotomy, stone extraction, and laparoscopic cholecystectomy. Surg Endosc 9:910, 1995 35. Gadacz T, Jamal A, Gorski TF, et al: Laparoscopic cholecystectomy during pregnancy. Surgical Rounds 20208, 1997 36. Geisler JP, Rose SL, Mernitz CS, et al: Non-gynecologic laparoscopy in second and third trimester pregnancy: Obstetric implications. J SOCLaparoendosc Surg 2:235, 1998 37. Gersin KS, Heniford BT, Arca MJ, et al: Alternative site entry for laparoscopy in patients with previous abdominal surgery. J Laparoendosc Adv Surg Tech 8:125, 1998 38. Ghumman E, Barry M, Grace PA: Management of gallstones in pregnancy. Br J Surg 841646, 1997 39. Glasgow RE, Visser BC, Harris HW, et al: Changing management of gallstone disease during pregnancy. Surg Endosc 12:241, 1998 40. Gouldman JW, Sticca RP, Rippon MB: Laparoscopic cholecystectomy in pregnancy. Am Surg 64:93, 1998 41. Graham G, Baxi L, Tharakan T Laparoscopic cholecystectomy during pregnancy: A case series and review of the literature. Obstet Gynecol Surg 53:566, 1998 42. Gurbuz AT, Peetz ME: The acute abdomen in the pregnant patients: Is there a role for laparoscopy? Surg Endosc 11:98, 1997 43. Halpern NB: Access problems in laparoscopic cholecystectomy: Postoperative adhesions, obesity, and liver disorders. Semin Laparosc Surg 5:92, 1998

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44. Halpem NB: Laparoscopic cholecystectomy in pregnancy: A review of published experiences and clinical considerations. Semin Laparosc Surg 5:129, 1998 45. Halpem NB: The difficult laparoscopy. Surg Clin North Am 76:603, 1996 46. Hart RO, Tamadon A, Fitzgibbons RJ, et al: Open laparoscopic cholecystectomy in pregnancy. Surg Laparosc Endosc 3:13, 1993 47. Hunter JG, Swanstrom L, Thorburg K Carbon dioxide pneumoperitoneum induces fetal acidosis in a pregnant ewe model. Surg Endosc 4268, 1994 48. Hutchinson CH, Traverso LW, Lee FT Laparoscopic cholecystectomy: Do preoperative factors predict the need to convert to open? Surg Endosc 8:875, 1994 49. Iafrati MD, Yarnell R, Schwaitzberg SD: Gasless laparoscopic cholecystectomy in pregnancy. J Laparoendosc Surg 6:127, 1995 50. Ivankovich AD, Miletich DJ, Albrecht RE,et al: Cardiovascular effect of intraperitoneal insufflation with carbon dioxide and nitrous oxide in the dog. Anesthesiology 42:281. 1975 -~_, . - ~ 51. Jackson SJ, Sigman HH: Laparoscopic cholecystectomy in pregnancy. J Laparoendosc Surg 5:399, 1995 52. Jamal A, Gorski TF, Nguyen HY, et al: Laparoscopic cholecystectomy during pregnancy. Surgical Rounds 10:468, 1997 53. Jorgensen JO, Hunt DO: Laparoscopic cholecystectomy: A prospective analysis of potential causes of failure. Surg Laparosc Endosc 3:49, 1993 54. Kammerer WS: Nonobstetric surgery during pregnancy. Med Clin North Am 63:1157, 1979 55. Kort 8, Katz VI, Watson WJ: The effect of nonobstetric operation during pregnancy. Surg Gynecol Obstet 177371, 1993 56. Kumar SS: Laparoscopic cholecystectomy in the densely scarred abdomen. Am Surg 64:1094, 1998 57. Lanzafame R Laparoscopic cholecystectomy during pregnancy. Surgery 118:627,1995 58. Lemaire BMD, van Erp WFM Laparoscopic surgery during pregnancy. Surg Endosc 11:15, 1997 59. Levrant SG, Bieber EJ, Bames RB: Anterior abdominal wall adhesions after laparotomy or laparoscopy. J Am Assoc Gynecol Laparosc 4353, 1997 60. Liberman MA, Phillips EH, Carrol B, et al: Management of choledocholithiasis during pregnancy: A new protocol in the laparoscopic era. J Laparoendosc Surg 5:399, 1995 61. Liu CV, Fan ST, Lair ECS, et al: Factors affecting conversion of laparoscopic cholecystectomy to open surgery. Arch Surg 131:98, 1996 62. Loffer FD, Pent D: Laparoscopy in the obese patient. Am J Obstet Gynecol 125:104, 1976 63. Martin IG, Dexter SPL, McMahon MJ: Laparoscopic cholecystectomy in pregnancy: A safe option during the second trimester? Surg Endosc 10:508, 1996 64. Mayol J, Garcia-Aguilar J, Ortiz-Oshiro E, et al: Risks of the minimal access approach for laparoscopic surgery: Multivariate analysis of morbidity related to umbilical trocar insertion. World J Surg 21:529, 1997 65. Mazze RI, Kallen B: Reproductive outcome after anesthesia and operation during pregnancy: A registry study of 5405 cases. Am J Obstet Gynecol 161:1178, 1989 66. McKellar DP, Anderson CT, Boynton CJ, et al: Cholecystectomy during pregnancy without fetal loss. Surg Gynecol Obstet 174465, 1992 67. McKenzie R, Wadhwa RK, Bedger RC: Noninvasive measurement of cardiac output during laparoscopy. J Reprod Med 24247, 1980 68. McKeman JB, Champion JK: Access techniques: Veress needle-initial blind trocar insertion versus open laparoscopy with the Hasson trocar. Endosc Surg Allied Tech 3:35, 1995 69. Miles RH, Carballo RE, Prinz RA, et al: Laparoscopy: The preferred method of cholecystectomy in the morbidly obese. Surgery 112:818, 1992 70. Miller K, Holbling N, Hutter J, et al: Laparoscopic cholecystectomy for patients who have had previous abdominal surgery. Surg Endosc 7400,1993 71. Morrel DG, Mullins JR, Harrison PB: Laparoscopic cholecystectomy during pregnancy in symptomatic patients. Surgery 112856, 1992

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72. Motew M, Ivankovich AD, Bieniarz J, et al: Cardiovascular effects and acid-base and blood gas changes during laparoscopy. Am J Obstet Gynecol 113:1002, 1973 73. Nuzzo G, Giuliante F, Tebala GD, et ah Routine use of open technique in laparoscopic operations. J Am Coll Surg 184:58, 1997 74. OConnor LA, Kavena CF, Horton S: The Phoenix Indian Medical Center experience with laparoscopic cholecystectomy during pregnancy. Surg Laparosc Endosc 6441, 1996 75. Panton ON, Nagy AG, Scudamore CH, et al: Laparoscopic cholecystectomy: A continuing plea for routine cholangiography. Surg Laparosc Endosc 5:43, 1995 76. Pasulka PS, Bistrian BR, Benotti PN, et al: The risks of surgery in obese patients. AM Intern Med 104:540, 1986 77. Pate1 M, Smart D: Laparoscopic cholecystectomy and previous abdominal surgery: A safe technique. Aust N Z J Surg 66309,1996 78. Paternoster DM, Floreani A, Sacco NA, et ak Chronic recurrent pancreatitis in pregnancy. Minerva Ginecol47561, 1997 79. Pemberton LB, Manax WG: Relationship of obesity to postoperative complications after cholecystectomy. Am J Surg 121537, 1971 80. Phillips H, Carroll BJ, Fallas MJ, et a1 Comparison of laparoscopic cholecystectomy in obese and non-obese patients. Am Surg 60:316, 1994 81. Poindexter AN, Ritter M, Fahim A, et al: Trocar introduction performed during laparoscopy of the obese patient. Surg Gynecol Obstet 165:57, 1987 82. Posta CG: Laparoscopic surgery in pregnancy: Report on two cases. J Laparoendosc Surg 6:203, 1995 83. Printen KJ, Ott RA: Cholecystectomy during pregnancy. Am Surg 44:432, 1978 84. Pucci RO, Seed RW Case report of laparoscopic cholecystectomy in the third trimester of pregnancy. Am J Obstet Gynecol 165:401, 1991 85. Reedy MB, Galan HL, Bean JD, et al: Laparoscopic insufflation in the gravid baboon: Maternal and fetal effects. J Am Assoc Gynecol Laparosc 2399, 1995 86. Reedy MB, Galan HL, Richards WE, et al: Laparoscopy during pregnancy: A survey of laparoendoscopic surgeons. J Reprod Med 4233,1997 87. Robinson SP, Hirtle M, Imbrie JZ, et al: The mechanics underlying laparoscopic intraabdominal surgery for obese patients. J Laparoendosc Adv Surg Tech A 8:11, 1998 88. Rusher AH, Fields 8, Henson K Laparoscopic cholecystectomy in pregnancy: Contraindicated or indicated? J Ark Med SOC89:383, 1993 89. Society of American Gastrointestinal Endoscopic Surgeons: Guidelines for laparoscopic surgery during pregnancy. Surg Endosc 12189, 1998 90. Samuellson S, Sjovall A: Laparoscopy in suspected ectopic pregnancy. Acta Obstet Gynecol Scand 51:31, 1972 91. Schirmer BD, Dix J, Edge SB, et al: Laparoscopic cholecystectomy in the obese patient. Ann Surg 216346, 1992 92. Schirmer BD, Dix J, Schmieg RD, et al: The impact of previous abdominal surgery on outcome following laparoscopic cholecystectomy. Surg Endosc 93085, 1995 93. Schorr R T Laparoscopic cholecystectomy and pregnancy. J Laparoendosc Surg 3291, 1993 94. Schreiber J H Laparoscopic appendectomy in pregnancy. Surg Endosc 4:100, 1990 95. Schreiber J H Results of outpatient laparoscopic appendectomy in women. Endoscopy 26292 1994 96. Schrenk P, Woisetschlager R, Rieger R, et al: A diagnostic score to predict the difficulty of a laparoscopic cholecystectomy from preoperative variables. Surg Endosc 12148, 1998 97. Schrenk P, Woisetschlager R, Wayand WU: Laparoscopic cholecystectomy: Cause of conversions in 1,300 patients and analysis of risk factors. Surg Endosc 925, 1995 98. Schwandner 0, Schiedeck TH, Bruch H: The role of conversion in laparoscopic colorectal surgery: Do predictive factors exist? Surg Endosc 13:151, 1999 99. Schwartzberg BS, Conyers JA, Moore J A First trimester of pregnancy laparoscopic procedures. Surg Endosc 11216, 1997 100. Shaked G, Twena M, Charuzi I: Laparoscopic cholecystectomy for empyema of gallbladder during pregnancy. Surg Laparosc Endosc 465, 1997

101. Sigman HH, Fried GM, Garzon J, et al: Risks of blind versus open approach to celiotomy for laparoscopic surgery. Surg Laparosc Endosc 3:296, 1993 102. Sikora SS, Kumar A, Saxena R, et al: Laparoscopic cholecystectomy: Can conversion be predicted? World J Surg 19:858, 1995 103. Simon JH: Biliary tract disease and related surgical disorders during pregnancy. Clin Obstet Gynecol 26:810, 1983 104. Soper NJ, Hunter JG, Petri RH: Laparoscopic cholecystectomy during pregnancy. Surg Endosc 6:115, 1992 105. Steinbrook RA, Brooks DC, Datta S: Laparoscopic cholecystectomy during pregnancy: Review of anesthetic management, surgical consideration. Surg Endosc 10:511, 1996 106. Swisher SG, Schmit PJ, Hunt KK, et al: Biliary disease during pregnancy. Am J Surg 168:576, 1994 107. Swisher SG, Hunt KK, Schmit PJ, et al: Management of pancreatitis complicating pregnancy. Am Surg 60:759, 1994 108. Thiet MD, Mittelstaedt CA, Herbst CA, et al: Cholelithiasis in morbid obesity. South Med J 77415, 1984 109. Thomas SJ, Brisson P: Laparoscopic appendectomy and cholecystectomy during pregnancy: Six case reports. J SOCLaparoendosc Surg 2:41, 1998 110. Unger SW, Scott JS, Unger HM, et al: Laparoscopic approach to gallstones in the morbidly obese patient. Surg Endosc 5:116, 1991 111. Vakili C, Knight R A technique for needle insufflation in obese patients. Surg Laparosc Endosc 3:489, 1993 112. Weber AM, Bloom GP, Allan TR, et al: Laparoscopic cholecystectomy during pregnancy. Obstet Gynecol 78:958, 1991 113. Weibel MA, Majno G: Peritoneal adhesions and their relation to abdominal surgery. Am J Surg 126:345, 1973 114. Westerband A, Van de Water JM, Amzallag M, et al: Cardiovascular changes during laparoscopic cholecystectomy. Surg Gynecol Obstet 175:535, 1992 115. Wiebke EA, Pruitt AL, Howard LE, et al: Conversion of laparoscopic to open cholecystectomy: An analysis of risk factors. Surg Endosc 10:742, 1996 116. Williams JK, Rosemurgy AS, Albrink MH, et al: Laparoscopic cholecystectomy in pregnancy: A case report. J Reprod Med 40:243, 1995 117. Wilson RB, McKenzie RJ, Fisher JW: Laparoscopic cholecystectomy in case reports. Aust N 2 J Surg 64:647, 1994 118. Wishner JD, Zolfaghari D, Wohlgemuth SD, et al: Laparoscopic cholecystectomy in surgery: A report of 6 cases and review of the literature. Surg Endosc 10:314, 1996 119. Wittgen CM, Andrus CH, Fitzgerald SD: Analysis of the hemodynamic and ventilatory effects of laparoscopic cholecystectomy. Arch Surg 126:997, 1991 120. Wolf JS: Laparoscopic access with a visualizing trocar. Tech Urol 3:34, 1997 121. Wongworawat MD, Aitken DR, Robles AE, et al: The impact of prior intra-abdominal surgery on laparoscopic cholecystectomy. Am Surg 60:763, 1994 122. Yu SC, Chen SC, Wang SM, et al: Is previous abdominal surgery a contraindication to laparoscopic cholecystectomy? J Laparoendosc Surg 4:31, 1994

Address reprilzt requests to Myriam J. Curet, MD, FACS ACC 2nd Floor Department of Surgery University of New Mexico Health Sciences Center 2211 Lomas Boulevard, NE Albuquerque, NM 87131-5341