Obesity does not adversely affect outcomes after laparoscopic splenectomy

Obesity does not adversely affect outcomes after laparoscopic splenectomy

The American Journal of Surgery (2013) 206, 52-58 Clinical Science Obesity does not adversely affect outcomes after laparoscopic splenectomy Helen M...

136KB Sizes 1 Downloads 77 Views

The American Journal of Surgery (2013) 206, 52-58

Clinical Science

Obesity does not adversely affect outcomes after laparoscopic splenectomy Helen M. Heneghan, M.D., Ph.D.a,*, Shohrat Annaberdyev, M.D.a, Vikram Attaluri, M.D.a, Tracy Pitt, M.D.b, Matthew Kroh, M.D.a, Sri Chalikonda, M.D.a, Stacy A. Brethauer, M.D.a, Steven Rosenblatt, M.D.a a

Department of Minimally Invasive Surgery, Bariatric and Metabolic Institute, M61, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; bDepartment of Bariatric Surgery, St. Mary’s Duluth Clinic, Duluth, MN, USA KEYWORDS: Laparoscopic splenectomy; Obesity; Morbidly obese; Morbidity; Surgical outcomes

Abstract BACKGROUND: Obesity is still considered a relative contraindication to laparoscopic splenectomy (LS). METHODS: All patients undergoing LS at our institution were classified as obese or nonobese (group A, body mass index [BMI] .30; group B, BMI ,30). Primary end points included conversion rate, operative complications, length of stay, operative time, and estimated blood loss (EBL). RESULTS: Three hundred seventy patients who underwent LS were included. Baseline characteristics were similar in groups A (n 5 127; mean BMI, 36.2 6 6.9 kg/m2) and B (n 5 243; mean BMI, 24.6 6 2.9 kg/m2). Conversion rates and overall morbidity were similar in both groups (9% vs 11% for conversion to open procedures, P 5 .621; 16% vs 16% for morbidity rates, P 5 .940). Length of hospital stay and EBL were also comparable (P 5 .643 and P 5 .544, respectively). Mean operative time was significantly increased in the obese group on multivariate analysis (170 vs 151 minutes, P 5 .021). CONCLUSIONS: Obesity does not adversely affect outcomes after LS. The laparoscopic approach is the optimal technique for splenectomy regardless of the patient’s weight. Ó 2013 Elsevier Inc. All rights reserved.

The development of minimally invasive surgical techniques has revolutionized many surgical procedures, including cholecystectomy, Nissen fundoplication, abdominal

Dr Chalikonda is a consultant for Covidien and Intuitive Surgical; Dr Kroh is a consultant for C.R. Bard and Covidien; Dr Brethauer is a consultant for C.R. Bard, Covidien, and Ethicon Endo-Surgery Inc, and Dr Rosenblatt is a consultant for C.R. Bard, Covidien, and Baxter Healthcare Corp. All other authors declare no conflicts of interest. Presented in part at the poster session of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) annual meeting, March 30–April 2, 2011, San Antonio, TX. * Corresponding author. Tel.:11-216-445-0797; fax: 11-216-445-1586. E-mail addresses: [email protected], [email protected] Manuscript received February 1, 2012; revised manuscript July 20, 2012 0002-9610/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2012.07.041

hernia repairs, and colectomy.1 Compared with access by laparotomy, the laparoscopic approach to major abdominal operations has been shown to decrease organ system impairment, resulting in significantly reduced perioperative morbidity and recovery time.2 Similarly, since the first report of laparoscopic splenectomy (LS) in 1991,3 it has surpassed the open technique as the approach of choice when splenectomy is indicated for a variety of reasons.4–8 Reported advantages of LS, compared with the traditional open splenectomy, include decreased perioperative morbidity and mortality rates, shorter recovery periods, and decreased length of hospital stay.9–12 Although most reported data demonstrate widespread overall acceptance of the laparoscopic method, some disadvantages have been noted, including longer operations and limitations of

H.M. Heneghan et al.

Laparoscopic splenectomy in the obese

this approach for massive splenomegaly.4,13 More recently, even these challenges are being overcome as experience with LS grows and improvements in technology occur. There remains conflicting data regarding the use of the laparoscopic approach for splenectomy in obese patients specifically. Morbid obesity presents a technical challenge in many abdominal surgical procedures. The excessive abdominal adiposity, and invariably enlarged fatty liver, reduces intra-abdominal working space and impairs visualization. In the embryonic period of laparoscopy, obesity was actually considered a contraindication for many operations, including cholecystectomy.14 Despite these early concerns, the laparoscopic approach has since become the gold standard approach for abdominal surgery in patients with increased body mass index (BMI) on the basis that it was shown to significantly reduce postoperative pain, promote a quicker return to activities, and result in a shorter hospital stay; wound complication rates were also dramatically decreased.15–20 With regard to the safest operative approach for splenectomy in obese individuals, data show that LS in this population is associated with increased blood loss and longer operative times, particularly in patients with massive splenomegaly.21–23 However, other reports have challenged these findings and indicate that the aforementioned benefits of laparoscopic surgery are also observed in obese individuals requiring splenectomy.11,12 Even among patients with splenomegaly, evidence has emerged to support LS as the procedure of choice.13 The aim of this study was to review our experience with LS in obese and nonobese patients to determine the feasibility, safety, and outcomes of the laparoscopic approach in this setting. We also sought to determine the effects of spleen size in obese patients undergoing LS.

Methods Study cohort After obtaining institutional review board approval, we conducted a retrospective review of a prospectively maintained splenectomy database at a tertiary referral minimally invasive surgical center. All patients who underwent LS between 1996 and 2011 were identified and included in this study. Patients’ medical records were reviewed and data obtained on their baseline demographics (age, sex, BMI), clinical details (comorbidities, American Society of Anesthesiologist [ASA] classification), primary diagnosis and indication for splenectomy, operative details (including weight of spleen), and perioperative outcomes. Patients were classified into groups according to their BMI; group A 5 BMI R30 kg/m2 or greater (obese) and group B 5 BMI 30 kg/m2 (nonobese). To evaluate the influence of splenomegaly on the feasibility and safety of LS in obese patients, we further divided the obese patient cohort (group A) into 2 subgroups based on spleen weight: group A1 5 obese patients without splenomegaly and group A2 5 obese patients

53 with splenomegaly. Splenomegaly was defined as a spleen weighing 500 g or more, as in previous studies.5,22

Laparoscopic splenectomy technique After thorough preoperative evaluation and having obtained informed written consent from patients, all cases were performed at a single institution by several experienced laparoscopic surgeons. The majority of cases were performed by 3 surgeons. Preoperative antimicrobial prophylaxis was administered, and all patients received appropriate vaccinations against encapsulated organisms 7 to 14 days before surgery. Our approach to perioperative and postoperative anticoagulation was to apply pneumatic compression devices to the lower limbs of all patients on admission and then to commence prophylactic doses of subcutaneous low molecular weight heparin on the first postoperative night. This was continued once daily for the duration of the patient’s hospital stay. This protocol was adhered to only if the patient’s platelet count was normal and it was determined that there was no significantly increased risk of bleeding. If significant thrombocytosis developed postoperatively (platelet count of approximately 1 ! 106/mL or greater), daily low-dose aspirin was started and continued after discharge. The LS technique was standardized and performed per the following brief description. With the patient under general anesthesia and in the right lateral decubitus position, the abdomen was entered with an optical trocar and pneumoperitoneum was established. Three additional 5-mm ports were inserted in standard fashion. The ligamentous attachments were transected using either sharp dissection or the harmonic scalpel. One of our ports was upsized to a 12-mm trocar, and the splenic hilum was visualized and divided using an endoscopic linear stapling device. The spleen was collected in an impervious specimen bag and removed after fragmentation or extension of a port site incision at the discretion of the operating surgeon. All specimens were weighed in the operating room before undergoing pathologic assessment. The procedure was converted to a laparotomy if excessive difficulty was encountered intraoperatively (including difficult anatomy, poor exposure or visualization, excessive bleeding, or excessive splenomegaly).

Study end points The primary outcomes evaluated in this study included conversion rate, operative time, estimated blood loss (EBL), length of hospital stay, postoperative morbidity, and mortality rates.

Data analysis Data were analyzed using the software package PASW Statistics, version 18.0 for Windows (SPSS, Inc, Chicago, IL). Descriptive statistics were computed for all variables,

54

The American Journal of Surgery, Vol 206, No 1, July 2013

and baseline patient characteristics are presented in numbers and percentages. Distribution of the data was checked for normality; parametric data are presented as means (6 standard deviation) and nonparametric data are presented as median with interquartile range (IQR). Comparisons of dichotomous groups, defined by BMI (,30 kg/m2 vs R30 kg/m2) and spleen weight (500 g vs R500 g), were performed with respect to blood loss, length of stay, and operative time using the Student 2-sample t test or the Mann-Whitney U test for parametric and nonparametric data, respectively. Groupings with more than 2 levels, such as a 3-level categorization of BMI (,30, 30 to 40, and R40 kg/m2), or groups formed by combinations of BMI and spleen weight, were compared using analysis of variance, followed by the Tukey honestly significant difference post hoc test or the Kruskal-Wallis test, followed by pairwise group comparisons using the Wilcoxon test. Group comparisons with respect to frequency of conversion or complications were performed with a chi-square test. P values are reported for individual comparisons; a P value of less than .05 was considered statistically significant.

terms of sex, age, and ASA grade preoperatively. The main indications for splenectomy were idiopathic thrombocytopenic purpura (ITP), lymphoproliferative disease, and autoimmune hemolytic anemia. A smaller proportion of patients in each group had other pathologic conditions of the spleen, including masses, tumors, or splenomegaly of unknown cause. ITP was a more common indication for splenectomy in obese patients than in nonobese patients (56% vs 39%; P 5 .002), whereas lymphoproliferative disease was more frequent in the nonobese group (30% vs 16%; P 5 .006). Preoperative platelet counts were, on average, similarly low in both groups (122 !103/dL in group A vs 129 ! 103/dL in group B; P 5 .535).

Operative data for laparoscopic splenectomy Operative details of the LS procedures, including conversion rates, duration of procedure, EBL, and mean length of hospital stay, are presented in Table 2. The rate of conversion to open splenectomy was 9% (n 5 12) in the obese group A and 11% (n 5 27) in the nonobese group B (P 5.621). EBL was similar in groups A and B (210 mL and 237 mL, respectively; P 5 .544). However, operating time was significantly longer for patients in group A (170 vs 151 minutes; P 5 .021). The mean spleen weight, which was recorded immediately after retrieval of the specimen, was higher in group A (536 g) than in group B (500 g), although the difference did not reach statistical significance (P 5 .580). Length of stay was also similar in both groups (median hospital stay, 2 days for group A vs 3 days for group B; P 5 .230).

Results Patient characteristics Between July 1996 and April 2011, 370 patients (51% women) underwent LS at a single tertiary level minimally invasive surgery center. In this consecutive series there were 127 obese patients (group A), with a mean BMI of 36.2 6 6.9 kg/m2. This subgroup was compared with 243 nonobese patients (group B), with a mean BMI of 24.6 6 2.9 kg/m2, with regard to baseline characteristics and outcomes of LS. Demographic and preoperative clinical details of the groups are presented in Table 1; both groups were comparable in

Table 1

Postoperative outcomes Morbidity and mortality. Overall postoperative morbidity was similar in both groups (16% vs 16%, respectively; P 5 .940). Specific details of these morbidities are illustrated in

Baseline characteristics of 370 patients who underwent LS

Variable

Group A obese

Group B nonobese

P value

N Age, y (mean 6 SD) Male/female (%) BMI, kg/m2[mean 6 SD] ASA grade median (IQR) Primary diagnosis and indication for LS, n (%) ITP Lymphoproliferative disease AIHA Other‡ Preoperative platelet count (103/dL) (mean 6 SD)

127 56 6 17 49/51 36.2 6 6.9 3 (3–3)

243 51 6 17 49/51 24.6 6 2.9 3 (2–3)

.013* .978† ,.001* .984x

71 (56) 21 (16) 11 (9) 24 (19) 129 6 116

95 (39) 72 (30) 27 (11) 49 (20) 122 6 107

.002† .006† .461† .702† .535*

AIHA 5 autoimmune hemolytic anemia; ASA 5 American Society of Anesthesiologists; BMI 5 body mass index; IQR 5 interquartile range; ITP 5 idiopathic thrombocytopenic purpura; LS 5 laparoscopic splenectomy; SD 5 standard deviation. *Student t test. † Chi-square test. ‡ Includes splenic mass, tumor, or unknown diagnosis. x Mann-Whitney U test.

H.M. Heneghan et al.

Laparoscopic splenectomy in the obese

Table 2 Operative details of 370 patients who underwent LS, according to obesity status Operative detail N Conversion to open splenectomy, n (%) Operating time, min (mean 6 SD) EBL, mL (mean 6 SD) Length of hospital stay (median [IQR]) Spleen weight, g (mean 6 SD)

Group A obese

Group B nonobese

P value

127 12 (9)

243 27 (11)

.621*

170 6 60

151 6 60

.021†

210 6 292 2 (2–4)

237 6 345 3 (2–5)

.544† .230‡

536 6 592

500 6 542

.580†

EBL 5 estimated blood loss; IQR 5 interquartile range; LS 5 laparoscopic splenectomy; SD 5 standard deviation. *Chi-square test. † Student t test. ‡ Mann-Whitney U test.

Table 3. Bleeding and infection represented the majority of morbidities encountered in the entire series (29 of 59 complications). Reoperation to control bleeding was required in 8 of 13 patients. Of 16 patients with infectious complications, 7 required readmission for further treatment and control of sepsis. Multivariate analysis, controlling for preoperative diagnosis and spleen weight, revealed no significant difference between obese and nonobese patients

Table 3

Outcomes of LS according to obesity status, n (%)

Variable N Duration of follow-up, mo (mean 6 SD) Mortality, n Overall morbidity, n (%)‡ Bleeding Infection (superficial or intra-abdominal abscess) Cardiopulmonary complication Pancreatic injury Other

Group A obese

Group B nonobese

P value

127 72 6 59

243 79 6 54

.375*

1 20 (16)

6 39 (16)

.260† .940†

6 (4.7) 5 (3.9)

7 (2.9) 11 (4.5)

.360 .791

3 (2.4)

5 (2.1)

.848

2 (1.6) 6 (4.7)

7 (2.9) 10 (4.1)

.439 .784

Pancreatic injury was diagnosed by postoperative hyperamylasemia, evidence of a pseudocyst, or a peripancreatic fluid collection on investigations for abdominal discomfort. Other morbidities included bowel injury, bowel obstruction, prolonged ileus, and persistent diarrhea with fever. LS 5 laparoscopic splenectomy; SD 5 standard deviation. *Student t test. † Chi-square test. ‡ Some patients had more than 1 complication. Cardiopulmonary complications included pulmonary embolus, pneumothorax, pneumonia, pulmonary edema, atrial fibrillation, and congestive heart failure.

55 with regard to rates of conversion to open splenectomy or postoperative complications (P 5 .309 and P 5 .814, respectively). After a mean overall follow-up of 76 6 56 months, which was similar in both groups (P 5 .375), there was 1 mortality in the obese group A, and there had been 6 deaths in the nonobese group B (P 5 .260). Three of these 7 mortalities were within 30 days of the LS procedure (all 3 in the nonobese group B). One patient with a preoperative diagnosis of ITP and multiple comorbidities died of overwhelming sepsis and multiorgan failure on postoperative day (POD) 8. A second early mortality occurred on POD 26, in an 80-year-old woman with autoimmune hemolytic anemia and a lymphoma in whom pneumocystis pneumonia and acute respiratory distress syndrome developed postoperatively. The third early mortality occurred on POD 10, in a 78-year-old man with comorbid ITP and a history of non-Hodgkin lymphoma. He experienced upper gastrointestinal bleeding, and subsequently aspiration pneumonia developed, which precipitated his death. The other 4 deaths occurred on PODs 36, 42, and 70, and 3 years postoperatively, from underlying disease or unrelated comorbidities. Effect of increased severity of obesity on outcomes. We performed a further subgroup analysis to determine whether increased severity of obesity influenced the outcomes of LS. Comparing patients with BMIs of 40 or more (n 5 25) with those with BMIs less than 30 (n 5 243), we observed no significant increase in the rates of complications, conversion, or operative duration in the morbidly obese subgroup compared with the nonobese group (P 5 .287, P 5 .268, and P 5 .087, respectively). Effect of splenomegaly on outcomes of obese patients undergoing laparoscopic splenectomy. To evaluate the influence of splenomegaly on the feasibility and safety of LS in obese patients, we performed a subgroup analysis of the 127 obese patients, based on spleen weight [group A1: 80 obese patients with normal-sized spleens; group A2: 47 obese patients with splenomegaly (.500 g)]. Obese patients with splenomegaly, whose mean spleen weight was 1052 6 680 g, were found to have significantly longer operating times (P , .001), greater EBL (P 5 .054), and higher rates of conversion to open splenectomy (17% vs 5%; P 5 .025), compared with obese patients with normal-sized spleens (Table 4). Median length of hospital stay was similar in groups A1 and A2 (2 days vs 3 days, respectively; P 5 .059). Overall, the postoperative morbidity rate was similar in both subgroups (11% vs 23%; P 5 .069). However, compared with group A1, patients in group A2 had a significantly higher incidence of bleeding complications (1% vs 11%; P 5 .016).

Comments Obesity complicates many surgical procedures by increasing the technical complexity of the operation as well as increasing the patient’s risk of postoperative

56

The American Journal of Surgery, Vol 206, No 1, July 2013

Table 4

Safety and efficacy outcomes of LS in obese patients, according to spleen size

Variable

Group A1 obese, normal size spleen

Group A2 obese, splenomegaly

P value

N Spleen weight, g (mean 6 SD) Conversion to open procedure, n (%) Overall morbidity, n (%) Operating time, min (mean 6 SD) EBL, mL (mean 6 SD) Length of hospital stay, days (median [IQR])

80 240 6 121 4 (5) 9 (11) 150 6 49 150 6 160 2 (2–3)

47 1,052 6 680 8 (17) 11 (23) 196 6 64 282 6 388 3 (2–4)

,.001* .025† .254† ,.001* .054* .059‡

EBL 5 estimated blood loss; IQR 5 interquartile range; LS 5 laparoscopic splenectomy; SD 5 standard deviation. *Student t test. † Chi-square test. ‡ Mann-Whitney U test.

morbidity.24 The advent of laparoscopic surgery greatly improved outcomes for obese surgical candidates, and it rapidly became the preferred approach for many abdominal procedures.25–27 Since the first splenectomy was performed laparoscopically in 1991, LS has been shown to be a generally safe and effective approach for the surgical treatment of benign and malignant pathologic conditions of the spleen.5–8,12 Early data caused concern when it appeared that LS in obese patients was associated with increased blood loss and longer operative times, particularly in patients with massive splenomegaly.22,23 These concerns have not been fully refuted, even though many of the studies reporting this data were performed in the period when experience with the technique was at the beginning of the learning curve. In this study, we reviewed our experience with LS over the past decade, with the specific aim of evaluating the safety and efficacy of LS in obese and nonobese patients. Our data demonstrate that LS in obese individuals is feasible and safe, regardless of the indication for the procedure, and outcomes are comparable to those in nonobese patients. Although the median operative time was significantly longer in obese patients (by 19 minutes), we observed similar blood loss, length of hospital stay, conversion rates, and postoperative morbidity when compared with a comparable group of nonobese patients undergoing LS. Longer operating times are not desirable, but as experience with the LS procedure has increased over time, the reported durations of the operation are decreasing. Early series published by Park et al12 and Targarona et al28 reported operative times of longer than 200 minutes. More recent series from Dominguez et al29 and the present study show that LS times range between 130 and 160 minutes, regardless of the patient’s BMI. A difference of 19 minutes between obese and nonobese patients, although statistically significant in our study, is unlikely to have any major clinical or cost implications. As noted by Dominguez et al,29 the minor increase in operating room time in obese patients undergoing LS is often related to patient positioning, gaining abdominal access, and retrieving the specimen, all of which are challenging in patients with abdominal obesity in particular. Overall, our data are encouraging and provide further evidence supporting the

laparoscopic approach as the preferred technique for performing splenectomy in patients of any body habitus. Thus far, the major limitation of the literature examining the impact of obesity on perioperative outcomes of LS has been the small numbers of patients included in existing studies. It has been difficult to draw definitive conclusions based on data from case reports or series including as few as 7 obese patients.3,21,30 The largest series to date in this setting, until now, was that by Dominguez et al,29 who described their experience with LS in 39 obese patients and 73 nonobese patients. Similar to the results of our current study, the authors demonstrated that LS was safe in obese individuals with a BMI of 30 to 40 kg/m2. Only when patients had severe and morbid obesity (BMI R40) did they experience higher rates of complications and conversions and longer operating times. In light of these results, we performed a further subgroup analysis on our own data, comparing outcomes of all patients with BMIs of 40 or greater (n 5 25) with those of patients with BMIs less than 30 (n 5 243). We found no significant increase in the rates of complications, conversions, or operative duration in the morbidly obese subgroup compared with the nonobese group (P 5 .287, P 5 .268, and P 5 .087, respectively). Considering the larger number of morbidly obese patients in our analysis, these data provide strong evidence that LS is safe even in severely obese individuals. The impact of splenomegaly on LS outcomes has been similarly debated. The presence of splenomegaly has long been considered a contraindication for LS, although recent reports indicate that this approach is feasible and safe and should be attempted for spleens of almost any size.4,22,31 The definition of splenomegaly remains inconsistent; longitudinal diameter greater than 15 cm as measured by preoperative ultrasonography, computed tomography, or magnetic resonance imaging has been proposed by the European Association for Endoscopic Surgery. It is often more practical to use spleen weight, measured after removal of the morcellated specimen, to define spleen enlargement. This approach has been used regularly in the literature to date and was the method used in the current study. We chose a cutoff weight of 500 g as the upper limit

H.M. Heneghan et al.

Laparoscopic splenectomy in the obese

of normal, based on a review of commonly used definitions at the outset of this study. Despite the heterogeneity in defining splenomegaly, most studies of LS in this setting, including the current study, have consistently demonstrated that it is associated with longer operative times, increased blood loss, higher rates of perioperative complications, longer hospital stays, and higher rates of conversion to open splenectomy when compared with LS for normal-sized spleens. However, there is also strong evidence that the laparoscopic approach is superior to open splenectomy for this group of patients.4 In cases of massive splenomegaly (diameter .20 cm or weight .1,000 g), a hand-assisted laparoscopic approach has been demonstrated to improve the feasibility of a minimally invasive approach, thereby sparing the patient the morbidity associated with an open procedure.32,33 Much of the experience with laparoscopic procedures in obese patients stems from the field of bariatric surgery. Over the past decade, the safety profile of bariatric procedures has improved substantially, largely resulting from the widespread transition to performing these cases laparoscopically.24,34 The ensuing rapid uptake of laparoscopic bariatric surgery worldwide has led to significant advances in laparoscopic instruments and to greatly improved expertise in the perioperative care of obese patients. This knowledge has translated well to other surgical subspecialties, and the LS procedure can be safely performed by adhering to basic principles and recommendations.29 Despite the accumulating evidence supporting LS as the procedure of choice for splenectomy in obese and nonobese patients, regardless of spleen size, the design of studies from which these data have emerged remains imperfect. There is still no prospective randomized trial comparing laparoscopic and open splenectomy in various scenarios such as obesity and splenomegaly. Proponents of LS may argue that there is no need and that it may not be ethically justifiable, given the obvious benefits of the laparoscopic approach reported in existing literature. At present, it appears that the only absolute contraindications to LS are those that preclude any laparoscopic procedure in a given patient, such as severe cardiopulmonary disease and portal hypertension with cirrhosis.

Conclusions LS is a feasible and safe procedure in obese patients. Although caution should be exhibited in obese patients with splenomegaly, this technique offers patients many benefits compared with the open surgical approach and should be considered the standard of care irrespective of body size.

References 1. Rosen M, Ponsky J. Minimally invasive surgery. Endoscopy 2001;33: 358–66.

57 2. Schauer PR, Ikramuddin S. Laparoscopic surgery for morbid obesity. Surg Clin North Am 2001;81:1145–79. 3. Delaitre B, Maignien B. Splenectomy by the laparoscopic approach. Report of a case [Article in French]. Presse Med 1991;20:2263. 4. Habermalz B, Sauerland S, Decker G, et al. Laparoscopic splenectomy: the clinical practice guidelines of the European Association for Endoscopic Surgery (EAES). Surg Endosc 2008;22: 821–48. 5. Knauer EM, Ailawadi G, Yahanda A, et al. 101 laparoscopic splenectomies for the treatment of benign and malignant hematologic disorders. Am J Surg 2003;186:500–4. 6. Walsh RM, Brody F, Brown N. Laparoscopic splenectomy for lymphoproliferative disease. Surg Endosc 2004;18:272–5. 7. Walsh RM, Heniford BT. Laparoscopic splenectomy for non-Hodgkin lymphoma. J Surg Oncol 1999;70:116–21. 8. Rosen M, Brody F, Walsh RM, et al. Outcome of laparoscopic splenectomy based on hematologic indication. Surg Endosc 2002;16: 272–9. 9. Brodsky JA, Brody FJ, Walsh RM, et al. Laparoscopic splenectomy. Surg Endosc 2002;16:851–4. 10. Cordera F, Long KH, Nagorney DM, et al. Open versus laparoscopic splenectomy for idiopathic thrombocytopenic purpura: clinical and economic analysis. Surgery 2003;134:45–52. 11. Kucuk C, Sozuer E, Ok E, et al. Laparoscopic versus open splenectomy in the management of benign and malign hematologic diseases: a ten-year single-center experience. J Laparoendosc Adv Surg Tech A 2005;15:135–9. 12. Park A, Marcaccio M, Sternbach M, et al. Laparoscopic vs open splenectomy. Arch Surg 1999;134:1263–9. 13. Kercher KW, Matthews BD, Walsh RM, et al. Laparoscopic splenectomy for massive splenomegaly. Am J Surg 2002;183:192–6. 14. Schirmer BD, Dix J, Edge SB, et al. Laparoscopic cholecystectomy in the obese patient. Ann Surg 1992;216:146–52. 15. Birgisson G, Park AE, Mastrangelo Jr MJ, et al. Obesity and laparoscopic repair of ventral hernias. Surg Endosc 2001;15:1419–22. 16. D’Alessio MJ, Arnaoutakis D, Giarelli N, et al. Obesity is not a contraindication to laparoscopic Nissen fundoplication. J Gastrointest Surg 2005;9:949–54. 17. Delaney CP, Pokala N, Senagore AJ, et al. Is laparoscopic colectomy applicable to patients with body mass index .30? A case-matched comparative study with open colectomy. Dis Colon Rectum 2005;48: 975–81. 18. Klasen J, Junger A, Hartmann B, et al. Increased body mass index and peri-operative risk in patients undergoing non-cardiac surgery. Obes Surg 2004;14:275–81. 19. Nguyen NT, Goldman C, Rosenquist CJ, et al. Laparoscopic versus open gastric bypass: a randomized study of outcomes, quality of life, and costs. Ann Surg 2001;234:279–89. discussion 289–91. 20. Nguyen NT, Ho HS, Palmer LS, et al. A comparison study of laparoscopic versus open gastric bypass for morbid obesity. J Am Coll Surg 2000;191:149–55. discussion 155–7. 21. Weiss 3rd CA, Kavic SM, Adrales GL, et al. Laparoscopic splenectomy: what barriers remain? Surg Innov 2005;12:23–9. 22. Heniford BT, Park A, Walsh RM, et al. Laparoscopic splenectomy in patients with normal-sized spleens versus splenomegaly: does size matter? Am Surg 2001;67:854–7. discussion 857–8. 23. Patel AG, Parker JE, Wallwork B, et al. Massive splenomegaly is associated with significant morbidity after laparoscopic splenectomy. Ann Surg 2003;238:235–40. 24. Schauer PR, Ikramuddin S, Gourash W, et al. Outcomes after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Ann Surg 2000; 232:515–29. 25. Korndorffer Jr JR, Fellinger E, Reed W. SAGES guideline for laparoscopic appendectomy. Surg Endosc 2010;24:757–61. 26. Miles RH, Carballo RE, Prinz RA, et al. Laparoscopy: the preferred method of cholecystectomy in the morbidly obese. Surgery 1992; 112:818–22. discussion 822–3.

58

The American Journal of Surgery, Vol 206, No 1, July 2013

27. Novitsky YW, Cobb WS, Kercher KW, et al. Laparoscopic ventral hernia repair in obese patients: a new standard of care. Arch Surg 2006; 141:57–61. 28. Targarona EM, Espert JJ, Cerdan G, et al. Effect of spleen size on splenectomy outcome. A comparison of open and laparoscopic surgery. Surg Endosc 1999;13:559–62. 29. Dominguez EP, Choi YU, Scott BG, et al. Impact of morbid obesity on outcome of laparoscopic splenectomy. Surg Endosc 2007;21:422–6. 30. Granderath FA, Pointner R. Laparoscopic splenectomy in an adipose elderly patient with symptomatic non-Hodgkin lymphoma-related splenomegaly and traumatic central splenic hematoma. Surg Laparosc Endosc Percutan Tech 2006;16:195–7.

31. Grahn SW, Alvarez 3rd J, Kirkwood K. Trends in laparoscopic splenectomy for massive splenomegaly. Arch Surg 2006;141:755–61. discussion 761–2. 32. Targarona EM, Balague C, Cerdan G, et al. Hand-assisted laparoscopic splenectomy (HALS) in cases of splenomegaly: a comparison analysis with conventional laparoscopic splenectomy. Surg Endosc 2002;16: 426–30. 33. Wang KX, Hu SY, Zhang GY, et al. Hand-assisted laparoscopic splenectomy for splenomegaly: a comparative study with conventional laparoscopic splenectomy. Chin Med J (Engl) 2007;120:41–5. 34. Colquitt J, Clegg A, Loveman E, et al. Surgery for morbid obesity. Cochrane Database Syst Rev 2005;2:CD003641.