2012 SSAT PLENARY PRESENTATION

Predictors of Unsuccessful Laparoscopic Resection of GastricSubmucosal Neoplasms

Sabha Ganai & Vivek N. Prachand & Mitchell C. Posner &

John C. Alverdy & Eugene Choi & Mustafa Hussain &

Irving Waxman & Marco G. Patti & Kevin K. Roggin

Received: 11 June 2012 /Accepted: 13 November 2012# 2012 The Society for Surgery of the Alimentary Tract

AbstractBackground While laparoscopy has become integral to the performance of foregut surgery, its optimal use in resection ofgastric submucosal neoplasms, including gastrointestinal stromal tumors (GISTs), remains uncertain. Concern exists fortechnical feasibility related to tumor size and location, as well as oncologic outcome.Methods From 2002 to 2012, 106 patients underwent resection for gastric submucosal neoplasms, comprising 79 laparo-scopic and 27 open resections. Median follow-up was 15 months.Results Patients were 62±14 years and 56 % male. Mean tumor size was 5.5±4.3 cm, with 76 % being GISTs. A total of8 (10 %) conversions occurred in the laparoscopic cohort. On multivariate analysis, conversion was predicted by size greaterthan 8 cm, while recurrence was predicted by mitotic index (p<0.05). Laparoscopic resection resulted in better perioperativeoutcomes, with less morbidity, operative time, blood loss, and length of stay (p<0.05). No significant difference was seen insurvival, with 90 % and 81 % alive 3 years after laparoscopic and open resection, respectively (HR 0.4; 95 % CI 0.1–1.3;p00.13).Conclusions Laparoscopic resection is feasible and effective in the management of gastric submucosal neoplasms, includingGISTs. Caution should be reserved for tumors greater than 8 cm. Oncologic outcome appears to be predicted by tumorbiology as opposed to surgical approach.

Keywords Laparoscopy . Gastric neoplasm . GIST .

Submucosal tumorsIntroduction

In 1992, the first report of laparoscopic resection of a gastricstromal tumor was published, describing the firing of anendoscopic linear stapling device across the base of anincidentally noted exophytic mass identified duringcholecystectomy.1 Since then, the integral role of laparosco-py in foregut surgery has become well-established. Withoptimization of instrumentation, energy sources, and sta-pling devices and their use in conjunction with flexibleendoscopy and intracorporeal suturing techniques, laparo-scopic gastric resection has become a part of the repertoireof general surgeons in managing both benign and malignantconditions.2,3 Moreover, the classification of the gastroin-testinal stromal tumor (GIST) as a distinct pathologic entityhas led to numerous reports assessing not only feasibility,but confirming the longer-term oncologic efficacy of lapa-roscopic resection.4–11 However, the ability to generalizelaparoscopic resection techniques to the spectra of gastricsubmucosal neoplasms remains uncertain, including concerns

Presented at the 53rd Annual Meeting of the Society for Surgery of theAlimentary Tract, May 18–22, 2012, San Diego, California.

S. Ganai :V. N. Prachand :M. C. Posner : J. C. Alverdy :E. Choi :M. Hussain :M. G. Patti :K. K. RogginDepartment of Surgery,The University of Chicago MedicalCenter, Chicago, IL, USA

I. WaxmanCenter for Endoscopic Research andTherapeutics, The University of ChicagoMedical Center, Chicago, IL, USA

K. K. Roggin (*)The University of Chicago Medicine,5841 S. Maryland Avenue, MC 5094,Chicago, IL 60637, USAe-mail: kroggin@surgery.bsd.uchicago.edu

J Gastrointest SurgDOI 10.1007/s11605-012-2095-z

of the ideal approach based on size6,12–14 and location11–13,15

of tumors. In order to better evaluate selection for a minimallyinvasive approach to resection of gastric submucosal neo-plasms, we present our experience with both laparoscopicand open techniques. We hypothesized that there are predic-tors of unsuccessful laparoscopic resection, with failures de-fined by conversions, complications, and poor oncologicoutcomes.

Materials and Methods

A retrospective medical record review was conducted on106 consecutive patients with gastric submucosal tumorswho underwent either open or laparoscopic resection be-tween October 1, 2002 and March 31, 2012, at the Univer-sity of Chicago Medical Center (UCMC) in Chicago,Illinois. Ethical standards were followed under the guidanceof the UCMC Institutional Review Board (protocol 11-060)to ensure protection of patient privacy and confidentiality.

Patient demographics, clinical presentation, and find-ings from preoperative imaging and endoscopy wereextracted from a prospectively maintained electronicmedical record (EMR). Pretreatment size of tumor wasdetermined from clinical data, prioritizing measurementsobtained via endoscopic ultrasound (EUS) over otherimaging modalities. Location of tumor was determinedfrom descriptions within operative reports. To be initial-ly classified in the laparoscopic cohort, laparoscopictechniques were required to be used for at least partof the mobilization of the lesion and/or stomach. Suc-cessful laparoscopic resections required completion ofthe resection and any additional reconstruction via lap-aroscopic techniques. Conversions were defined as anycases that initially started laparoscopically and pro-ceeded to open resection and/or reconstruction. Casesutilizing laparoscopy for purely diagnostic purposes(i.e., to rule out metastatic disease prior to resection)were classified in the open cohort.

Laparoscopic gastric resection techniques, includinglaparoscopic-assisted endoscopic submucosal resection,have been described in detail in prior publications.1,2,16

Except for one case, laparoscopic transgastric resectionwas performed through an anterior gastrotomy17 ratherthan via intragastric placement of balloon trocars.18

Anterior gastrotomy defects were closed using intracor-poreal suture techniques. Hand-assisted laparoscopicsurgery was not utilized in this series. The decision toproceed with an open resection was based on factorsincluding surgeon expertise and preference, tumor loca-tion, tumor size, and multivisceral involvement as dem-onstrated on preoperative axial imaging, if performed.The decision to provide neoadjuvant imatinib was

based on tumor size, multivisceral involvement, and adiagnosis of GIST. Most patients were discussed in amultidisciplinary tumor board where both biologic andtechnical issues were considered.

Pathologic data were extracted from pathology reports. Adiagnosis of GIST was confirmed via immunohistochemicalstaining for CD117, supplemented by CD34 and/or DOG1immunohistochemistry. Determination of pathologic sizewas based on the greatest gross dimension reported by thepathologist. Determination of resection status was based ona combination of pathologic determination of margins andclinical data as provided within operative reports. All enu-cleations were thus considered R1 resections (microscopi-cally positive), despite no remark on examination by thepathologist. Any patient with gross residual disease at com-pletion of surgery was considered to have undergone an R2resection (macroscopically positive). Pathologic staging wasperformed in accordance to the American Joint Committeeon Cancer (AJCC) 7th edition staging system for gastricGIST.19

Postoperative complications were scored according to theExpanded Classification of the Accordion Severity GradingSystem of Surgical Complications.20 Time to last follow-upwas based on the date of last clinical and/or imaging exam-ination as reported in the EMR, with censoring for patientsnoted as alive (overall survival) or alive with no evidence ofdisease (disease-free survival). Date of recurrence was basedon the date of a positive biopsy or unequivocal imagingstudy. Date of death was supplemented from data obtainedfrom the Social Security Death Index.

Data are reported as means with standard deviations(SD) or medians with interquartile ranges (IQR), with theexception of Table 7, which reports means with thestandard error of the mean. Comparative statistics wereperformed using Student’s t test or ANOVA for normallydistributed data and the Mann–Whitney rank sum test forordinal variables and non-normally distributed data. Com-parisons of categorical variables were performed usingchi-square or Fisher exact tests. Unconditional multiplevariable logistic regression was performed to determineindependent predictors of conversion and recurrence, withinclusion in the model based on a univariate p value lessthan 0.10. Odds and hazard ratios are reported with 95 %confidence intervals (CI). Time-to-event analysis wasperformed using the Kaplan–Meier method, with the logrank test used for comparisons between groups. A Coxproportional hazards model was used to identify indepen-dent predictors of survival using stepwise inclusion ofmultiple variables. Significance was determined accordingto an α of 0.05. Statistical analysis was performed withEpiInfo version 3.5.3 (Centers for Disease Control,Atlanta, GA). Survival curves are depicted using Graph-Pad Prism version 5.04 (La Jolla, CA).

J Gastrointest Surg

Results

Table 1 summarizes the demographics and preoperativecharacteristics of patients with gastric submucosal neo-plasms who underwent an attempt at laparoscopic (n079)or open resection (n027). Patients undergoing open surgerywere more likely to present with abdominal pain than thoseundergoing a laparoscopic resection (Fig. 1a; 52 vs. 26 %, p<0.05). Despite similar proportions of elective cases,patients in the open cohort were less likely to have preop-erative EUS (67 vs. 87 %, p<0.05). There was significantlygreater use of neoadjuvant imatinib in the open group (26vs. 5 %, p<0.01), with an approximately 6-month greatertime interval from diagnosis to operative intervention in thegroup undergoing open surgery (p<0.05). A similar distri-bution of lesions throughout the stomach was noted betweencohorts, with a slightly greater proportion of posterior-walltumors in the open group.

A total of 8 (10 %) laparoscopic cases were converted toopen, which occurred secondary to a failure to progressrather than for urgent indications. Table 2 summarizes theoperative and pathologic data for the laparoscopic (n071),converted (n08), and open (n027) groups. Median pretreat-ment lesion size was 3 cm (IQR 2–4), 8 cm (IQR 3–12), and8 cm (IQR 5–11), respectively (p<0.0001). The largest

lesion resected in each group was 10.5, 15.5, and 24.0 cmin greatest dimension on final pathology. Despite theoreticalconcerns for tumor spillage with laparoscopy, there were noiatrogenic ruptures of the tumor pseudocapsule in the lapa-roscopic group. Overall, the laparoscopic group had signif-icantly shorter operating times and less blood loss than theopen and converted groups (p<0.0001). Creation of a gas-troenteric anastomosis was more frequent in the open groupthan in the laparoscopic group (37 vs. 5 %, p<0.0001).Patients were also more likely to require multivisceral re-section in the open group, which most frequently involvedremoving the distal pancreas and the spleen.

The majority of lesions resected were GIST (76 %),followed by leiomyoma (9 %), schwannoma (6 %), andcarcinoid tumor (3 %). Figure 1b demonstrates choroplethmaps that summarize lesion location within the stomach foreach histologic subtype. Notably, among the 10 leiomyomain this series, 90 % were located in the cardia or gastro-esophageal (GE) junction, and the one that was located inthe fundus was 9.5 cm and underwent open resection. Forthe nine patients with leiomyoma that had preoperativeEUS-guided FNA biopsies, three were consistent with leio-myoma, three were suspicious for GIST, and three werenondiagnostic due to a hypocellular sample. Median sizefor leiomyoma was 5.3 cm (IQR 3.6–9.5), reaching a

Table 1 Patient demographicsand preoperative characteristics

BMI body mass index, EUS en-doscopic ultrasound, GEgastroesophageal

Laparoscopic cohort(n079)

Open cohort(n027)

p

Age (y) 62.2 ±14.9 62.7±9.6 0.91

Gender (male) 43 (54 %) 16 (59 %) 0.66

BMI (kg/m2) 29.8±7.3 28.1±5.5 0.40

Ethnicity 0.36

-Caucasian 53 (68 %) 16 (60 %)

-African-American 18 (23 %) 7 (26 %)

-Hispanic 4 (5 %) 2 (7 %)

-Asian 3 (4 %) 2 (7 %)

Recurrent disease 2 (3 %) 3 (11 %) 0.07

Preoperative EUS 69 (87 %) 18 (67 %) 0.02

Pretreatment size (cm) 3.9±2.7 9.5±6.8 <0.0001

Elective case 72 (91 %) 22 (82 %) 0.18

Prior laparotomy 21 (27 %) 6 (22 %) 0.61

Interval from diagnosis to surgery (months) 4.4±8.6 10.1±15.7 0.02

Neoadjuvant imatinib 4 (5 %) 7 (26 %) 0.002

Posterior location 35 (44 %) 16 (59 %) 0.18

Gastric mass location 0.93

-GE junction/cardia 13 (17 %) 6 (22 %)

-Fundus 14 (17 %) 4 (15 %)

-Greater curvature 25 (32 %) 11 (41 %)

-Lesser curvature 17 (22 %) 2 (7 %)

-Antrum/pylorus 10 (13 %) 4 (15 %)

J Gastrointest Surg

maximum of 15 cm. Schwannoma (n06) were smaller at3.2 cm (IQR 2.0–5.0), reaching a maximum of 6.5 cm, andwere most frequently seen in the fundus (50 %), followed bythe greater and lesser curvatures. All biopsies of schwanno-mas were nondiagnostic or suggestive of a diagnosis ofGIST. In contrast, the three carcinoids in this series wereall amenable to accurate preoperative biopsy, and werelocated in the lesser and greater curvatures. They alsotended to be the smallest of lesions, at a median of 2.1 cm(IQR 1.4–2.2).

Table 3 summarizes the pathologic data for gastricGISTs. The majority of those amenable to laparoscopicresection were between 2–5 cm in size, while the majorityof conversions and open cases comprised tumors greaterthan 5 cm. A diagnosis of GIST on preoperative biopsyhad a sensitivity of 90 %, specificity of 36 %, and accuracyof 75 %. Sixty percent of laparoscopically resected lesions

were Stage IA (less than 5 cm and less than 5 mitoses per 50high-power fields [HPF]), indicating a low-risk for recur-rence. By contrast, only 23 % of conversions and open caseswere Stage IA (p<0.01).

Table 4 summarizes the postoperative and follow-up datafor the series. Patients undergoing successful laparoscopicresection had a significantly lower hospital length of stay,with a median of 3 days (IQR 2–4) in comparison to 7 days(IQR 5–9, p<0.0001). Laparoscopic resection was also as-sociated with significantly less surgical site infections andpostoperative arrhythmias (p<0.01). Overall complicationswere also less severe when scored according to the Accor-dion Severity Grading System (Table 4; Fig. 2a; p<0.0001).20 There were significantly more patients with nocomplications in the laparoscopic compared to the opengroups (85 vs. 34 %; p<0.0001). In-hospital mortality in-cluded a massive myocardial infarction in one patient in thelaparoscopic group, and hospice care initiated after devel-opment of cardiogenic shock in one metastatic patient in theopen group. The need for a second operative procedure inthe laparoscopic group (n02) included management of anincarcerated port-site hernia, as well as an iatrogenic gastricoutlet obstruction requiring revision to a Billroth II recon-struction. This patient initially underwent transgastric resec-tion of an endophytic 5.4 cm antral GIST, leaving amarkedly narrowed gastric outlet at the level of the incisura.The single re-operation in the open group was related tomanagement of an anastomotic leak.

In the subgroup of successful laparoscopic resections,28 % of posteriorly based lesions were approached by trans-gastric wedge resection, while 65 % were amenable tostandard extraluminal wedge resection, and 6 % requiredlaparoscopic resection with gastroenteric anastomosis.There was a trend toward an increased rate of conversionwith lesions at the lesser curvature (18 %) compared to othersites (8 %), although this was not significant (p00.35). Non-standard approaches (e.g., transgastric resection, gastrecto-my) were used in 36 % of lesser-curvature lesions that weresuccessfully managed laparoscopically. With univariateanalysis, predictors of conversion included tumor size great-er than 8 cm and multivisceral tumor involvement (p<0.05).Table 5 summarizes the multivariate model where the onlyindependent predictor of conversion was tumor size greaterthan 8 cm (p<0.01).

Recurrences in the laparoscopic group occurred in threeindividuals, including one patient with a locally recurrentgastric carcinoid, one patient with a low grade, 3.4 cm GISTwho developed liver and pelvic recurrences, and one patientwith a high-grade, 8.0 cm GIST who developed a mass inthe hepatorenal fossa. Recurrences in the GIST patients whohad open resections were associated with large size

<25%25-50%50-75%>75%

0%

a

b 76% GIST 9% Leiomyoma

6% Schwannoma 3% Carcinoid

Fig. 1 Presenting features of gastric submucosal neoplasms undergo-ing resection (n0106). a Symptoms based on presentation amongpatients undergoing laparoscopic (n071), conversion to open (n08),and primary open resection (n027). Significant differences are noted inthe presentation of abdominal pain between laparoscopic and openresection groups (*p<0.01). b Gastric choropleth maps demonstratinglocation of tumor based on histologic type of submucosal neoplasm.Gastric anatomical regions include cardia/gastroesophageal junction,fundus, greater curvature, lesser curvature, and antrum/pylorus

J Gastrointest Surg

(maximal dimension of 9.3±2.3 cm) and high mitotic rate(mean 13±14 mitoses per 50 HPF). Liver metastases werefound in 71 % of open recurrences, while the remaining tworecurrences were local. Mean time to recurrence was 36.5±27.1 months for laparoscopic cases and 23.5±13.8 monthsfor open cases. With univariate analysis, predictors of recur-rence included tumor size, grade, and an open procedure(p<0.05). Table 6 summarizes a multivariate model forrecurrence, where the only independent predictor ofrecurrence was a tumor mitotic index greater than 5per 50 HPF (p<0.05).

Median follow-up was 9 months (IQR 1–32) after lapa-roscopic resection and 30 months (IQR 4–44) for conver-sions and open cases. There was no significant difference inoverall survival between groups, with 90 and 81 % alive at3 years after laparoscopic and open resection, respectively(HR 0.4; 95 % CI 0.1–1.3; p00.13; Fig. 2b). No significantdifferences in overall and disease-free survival by procedure

type were noted when controlling for tumor size, grade, andimatinib use in a Cox proportional hazards model.

Discussion

Submucosal tumors of the gastrointestinal tract are mes-enchymal tumors that can be classified based on myo-genic origin (i.e., leiomyomas and leiomyosarcomas),neurogenic origin (i.e., schwannomas and granular celltumors), vascular origin (i.e., hemangiomas and lym-phangiomas), and other, including gastrointestinal stro-mal tumors, carcinoids, lipomas, metastases, andheterotopic pancreatic tissue.21,22 In the stomach, approx-imately 70 % of these lesions when evaluated and sam-pled by EUS will be GISTs.23 While GISTs appearphenotypically similar to myogenic tumors, they demon-strate immunohistochemical characteristics that bear

Table 2 Operative and finalpathological data Laparoscopic

(n071)Converted(n08)

Open(n027)

p

Laparoendoscopic approach 7 (10 %) 0 0 n/a

Operative time (min) 132±52 247±115 230±111 <0.0001

Estimated blood loss (mL) 35±66 342±402 364±279 <0.0001

Gastric procedure 0.0004

-Wedge or sleeve resection 52 (73 %) 6 (75 %) 16 (59 %)

-Transgastric wedge resection 8 (11 %) 1 (13 %) 0

-Perigastric mass resection 2 (3 %) 0 1 (4 %)

-Endoscopic submucosal resection 3 (4 %) 0 0

-Enucleation 2 (3 %) 1 (13 %) 0

-Gastrectomy with reconstruction 4 (6 %) 0 10 (37 %)

Multivisceral resection 1 (1 %) 2 (25 %) 11 (41 %) <0.0001

Pathological size (cm) 4.0±2.1 8.0±4.7 8.6±6.1 0.0001

-Median size (IQR, cm) 3.6 (2.5–5.1) 8.9 (4.1–10.8) 7.7 (4.0–11.5)

-Maximum size (cm) 10.5 15.5 24.0

Histology 0.04

-GIST 50 (70 %) 7 (88 %) 24 (89 %)

-Leiomyoma 7 (10 %) 1 (12 %) 2 (7 %)

-Schwannoma 6 (9 %) 0 0

-Carcinoid 3 (4 %) 0 0

-Lipoma 2 (3 %) 0 0

-Adenomyoma 1 (1 %) 0 0

-Heterotopic pancreatic tissue 1 (1 %) 0 0

-Inflammatory fibroid polyp 1 (1 %) 0 1 (4 %)

Resection status: 0.07

-R0 (negative) 68 (96 %) 6 (75 %) 25 (93 %)

-R1 (microscopic) 3 (4 %) 1 (13 %) 1 (4 %)

-R2 (gross) 0 1 (13 %) 1 (4 %)

J Gastrointest Surg

resemblance to the interstitial cells of Cajal, characterized byover-expression of CD117 (a marker of c-kit) in 95 % ofcases.24,25 Over the past decade, the expanding role of imati-

nib and tyrosine kinase inhibitors has allowed GISTs to serveas an ideal model for the molecular-based diagnosis andtreatment of cancer.26,27

Table 3 Final pathological datafor gastrointestinal stromaltumors

ypCR complete pathological re-sponse after neoadjuvantimatinib

Laparoscopic(n050)

Converted(n07)

Open(n024)

p

pT 0.001

-1 (<2 cm) 5 (10 %) 1 (14 %) 3 (13 %)

-2 (2–5 cm) 32 (64 %) 1 (14 %) 4 (17 %)

-3 (5–10 cm) 12 (24 %) 2 (29 %) 7 (29 %)

-4 (>10 cm) 1 (2 %) 3 (43 %) 7 (29 %)

Mitotic index (mitoses/50 HPF) 4.6±10.0 0.7±0.5 6.2±12.3 0.46

High grade: >5 mitoses/50 HPF 10 (20 %) 0 10 (44 %) 0.24

Necrosis 4 (8 %) 1 (14 %) 7 (29 %) 0.06

Ulceration 3 (6 %) 1 (14 %) 1 (4 %) 0.62

Pathologic Stage <0.0001

-0 (ypCR) 0 0 4 (17 %)

-IA (<5 cm, low grade) 30 (60 %) 2 (29 %) 5 (21 %)

-IB (5–10 cm, low grade) 9 (18 %) 2 (29 %) 5 (21 %)

-II (<5 cm, high grade or >10 cm, low grade) 7 (14 %) 2 (29 %) 3 (13 %)

-IIIA (5–10 cm, high grade) 4 (8 %) 0 2 (8 %)

-IIIB (>10 cm, high grade) 0 0 2 (8 %)

-IV (N1 or M1) 0 1 (14 %) 3 (13 %)

Neoadjuvant imatinib 2 (4 %) 2 (29 %) 7 (29 %) 0.006

Adjuvant imatinib 15 (30 %) 4 (57 %) 11 (46 %) 0.22

Table 4 Postoperative morbidi-ty and mortality

LOS length of stay; PRBCspacked red blood cells; TPN to-tal parenteral nutrition; MSOFmulti-system organ failure

Laparoscopic(n071)

Converted(n08)

Open(n027)

p

Hospital LOS (days) 3.3±3.7 6.0±1.6 8.4±5.7 <0.0001

Surgical site infections 1 (1 %) 1 (13 %) 6 (22 %) 0.002

Superficial 1 (1 %) 1 (13 %) 3 (11 %)

Deep space 0 0 3 (11 %)

Anastomotic dehiscence 0 0 2 (7 %) 0.05

Postoperative arrhythmia 0 0 4 (15 %) 0.002

Myocardial infarction 1 (1 %) 0 1 (4 %) 0.70

Pneumonia 1 (1 %) 0 0 0.78

Deep venous thrombosis 2 (3 %) 0 3 (11 %) 0.18

Pulmonary embolism 0 0 1 (4 %) 0.23

Accordion severity grading system <0.0001

0—No complications 60 (85 %) 3 (38 %) 9 (33 %)

1—Minor (wound, foley) 3 (4 %) 2 (25 %) 5 (19 %)

2—minor (PRBCs, TPN, antibiotics) 4 (6 %) 3 (38 %) 8 (30 %)

3—Endoscopic/radiologic intervention 1 (1 %) 0 2 (7 %)

4—Operative intervention 2 (3 %) 0 1 (4 %)

5—MSOF 0 0 1 (4 %)

6—In-hospital death 1 (1 %) 0 1 (4 %)

J Gastrointest Surg

Table 7 summarizes the experience of 37 independentcase series examining outcomes after laparoscopic resectionfor gastric submucosal neoplasms (n01174), including ourown.4–15,28–50 While these studies vary in their design andinclusion criteria, the majority focus on laparoscopic GISTresections. Favorable operative times and reduced estimatedblood loss are described, as well as hospital length of staysthat are less than or at least comparable to open resection.Satisfactory perioperative outcomes have been reported,

including conversion rates of 5 %, reoperations in 1 %,and postoperative mortality in 0.4 %. While these may bereflective of optimal selection for laparoscopy based onpreoperative size and location of lesions, the biologicalbehavior of these tumors may play an equally important rolein long-term outcomes.

While gastrointestinal (GI) bleed is commonly describedas a presenting symptom for GIST,25 our data suggest thatabdominal pain is also a common presenting symptom thatwas seen in half of patients requiring open resection. Thismay relate to larger size, posterior location, or multivisceralinvolvement, which were features of note in the open co-hort. Among patients presenting with GI bleed, there was nodifference in likelihood of an open vs. laparoscopic ap-proach. In addition, the greater use of neoadjuvant imatinibin the open group correlates with size and the expanded timeinterval of time seen between diagnosis and surgery. Therewas less use of endoscopic ultrasound in the open group,which may be explained by (1) a decision to operate withoutfurther diagnostic studies due to a large, resectable tumor onaxial imaging, or (2) a patient who already had diagnosis ofGIST by initial endoscopic biopsy and was being consideredfor neoadjuvant imatinib. Laparoscopically resected tumorstended to be smaller which may be why EUS utilization wasgreater; these tumors were either initially detected by EUSor best accessed via EUS-guided FNA.

The overall accuracy of EUS-FNA cytology for malig-nant disease, including GIST, has been reported as 80–90 %.Accuracy for submucosal tumors, however, is closer to50 %, with almost half of biopsy specimens beinginadequate.21 Indeed, we found indeterminate results in themajority of schwannomas and leiomyomas assessed byEUS-guided FNA in our series, with a presumptive diagno-sis of GIST given until pathological analysis after resection.While we report a sensitivity of 90 %, overall diagnosticaccuracy for GIST in our series was 75 %, accounting for ahigh false-positive rate for other stromal tumors deemedsuspicious for GIST. This becomes particularly importantfor leiomyomas, which are often located in the cardia andgastroesophageal junction, and may be amenable to enucle-ation rather than wedge resection. As not all submucosallesions are GISTs, it is important to account for the chal-lenge in accurate preoperative diagnosis as this has impli-cations in the planned surgical approach.

Our series is limited by bias related to selection and itsretrospective design. While our attempts at laparoscopicresection occurred in 75 % of cases, this has increased from50 % of cases seen between 2002 and 2004 to 89 % of casesseen from 2010 to 2012 (p<0.01). Consideration of imagingcharacteristics suggesting a complex resection related to sizeand multivisceral involvement in GISTs may have influenced

Laparoscopic (n=71) Converted (n=8) Open (n=27)0

20

40

60

80

100

0 - No complications1 or 2 - Minor Complications3 or 4 - Interventional5 or 6 - MOSF or Death

Gastric Submucosal Neoplasm Resections

Accordian Severity Grading System for Postoperative Complications

Per

cent

age

0 12 24 36 48 60 72 84 96 108

0

20

40

60

80

100Open/Conversions

Overall Survival (months)

Laparoscopic

Per

cent

Sur

viva

la

b

Fig. 2 Outcomes from successful laparoscopic resection of gastricsubmucosal neoplasms. a Accordion Severity Grading System com-paring complications after laparoscopic resection (n071), conversions(n08), and open resection (n027; p<0.0001). b Overall survivalcomparing successful laparoscopic resections (n071) with conversionsand open resections (n035). Median survival is 106.1 months for theopen group compared to undefined in the laparoscopic group. Three-year survival was 90 and 81 % for the open and laparoscopic groups,respectively (hazard ratio, 0.42; 95 % CI, 0.14–1.30; p00.13). Medianfollow-up is 15 months

J Gastrointest Surg

both the use of neoadjuvant imatinib and the decision toproceed with an open resection. As this study occurred at atertiary-care comprehensive cancer center, the data are limitedin follow-up, especially for the majority of low-risk lesions.The presence of selection bias is important to appreciate, andhopefully accounted for by variables included in the multivar-iate models.

The role of laparoscopy in the resection of gastricsubmucosal neoplasms is important. The value of sys-tematic lymph node dissection and anatomical resectionhas been largely refuted for what was historicallyknown as gastric leiomyosarcoma after numerous reportsfailed to show lymphatic metastasis or any survivalbenefit from lymphadenectomy.50,51 In addition, the roleof margin status has been shown to not be predictive ofsurvival after primary resection of GIST, allowing forperformance of wedge resections to grossly-normaltissue.52 These features have allowed laparoscopic tech-niques to be both feasible and oncologically safe ifperformed properly in well-selected patients.

In 2004, the European Society for Medical Oncologypresented a consensus conference on the management ofGIST that recommended against laparoscopic surgery ow-ing to a higher risk of tumor rupture, but stated that it “mightbe accepted in cases of small (<2 cm) intramural tumors”.53

In 2008, the Japan Society of Clinical Oncology identifiedthat laparoscopic resection may be safely performed for

GISTs or submucosal tumors under 5 cm.54 While con-cerns about the appropriateness of laparoscopy for coloncancer have prompted randomized-controlled trials dem-onstrating non-inferiority,55 it is unlikely that arandomized-controlled trial addressing this question willbe feasible in the setting of GIST, partly because of itsrelative infrequency as an entity. While several investi-gators have made comparisons between open and lapa-roscopic cohorts,10,40,42,56 there are currently only twosize-matched case–control studies comparing laparoscop-ic and open surgery, demonstrating similar oncologicoutcomes with superior postoperative recovery.11,13

In our analysis of unsuccessful outcomes after lapa-roscopy for gastric submucosal neoplasms, the data sug-gest that laparoscopic techniques may be less suitablefor tumors greater than 8 cm as this was an independentpredictor of conversion. Facility with intracorporeal su-turing and gastrointestinal reconstruction may haveallowed for favorable outcomes in complex laparoscopiccases involving posteriorly based lesions requiring trans-gastric approaches. These approaches may have alsoincreased the feasibility of laparoscopic excision at com-plex locations including the lesser curvature and antrum.While conversion to an open approach may reflectsound surgical judgment rather than a “failure” per se,it is important to note that several open cases andconversions required en bloc resection of multiple

Table 5 Multivariate Model for Predictors of Conversion

Variable Conversions (n08) Laparoscopic success (n071) Univariate p Odds ratio (95 % CI) Multivariate p

Anastomosis 0 4 (6 %) 0.49 − −

Abdominal pain 4 (50 %) 16 (24 %) 0.11 − −

BMI 31.9±8.1 30.0±7.2 0.38 − −

Prior laparotomy 3 (38 %) 18 (26 %) 0.50 − −

Posterior lesion 6 (75 %) 29 (41 %) 0.07 5.03 (0.66–38.57) 0.12

Multivisceral 2 (25 %) 1 (1 %) 0.001* 7.95 (0.13–467.73) 0.32

Size>8 cm 5 (63 %) 5 (7 %) <0.0001* 18.48 (2.29–149.38) 0.006*

*p<0.05

Table 6 Multivariate Model for Predictors of Recurrence

Variable Recurrence (n010) No recurrence (n096) Univariate p Odds ratio (95 % CI) Multivariate p

R0 status 9 (90 %) 90 (94 %) 0.65 − −

Adjuvant imatinib 4 (40 %) 26 (27 %) 0.46 − −

Prior recurrence 1 (10 %) 4 (4 %) 0.41 − −

Neoadjuvant imatinib 2 (20 %) 9 (9 %) 0.30 − −

Size (cm) 7.9±3.4 5.3±4.3 0.01* 0.99 (0.85–1.14) 0.86

Mitoses>5 per 50 HPF 5 (50 %) 14 (15 %) 0.006* 4.68 (1.04–21.06) 0.04*

Laparoscopy 3 (30 %) 68 (71 %) 0.009* 0.21 (0.04–1.04) 0.06

*p<0.05

J Gastrointest Surg

Tab

le7

Laparoscopicresectionof

gastricsubm

ucosal

neop

lasm

s

Autho

rYear

NGISTs

n(%

)Size(cm)

n(%

)ORtim

e(m

in)

EBL

(mL)

LOS

(d)

Conversions

n(%

)Mortality

n(%

)Reoperatio

nsn(%

)Recurrences

n(%

)Follow-up

(mon

ths)

Geis2

819

968

NR

4.6

143

NR

3.5

00

NR

NR

NR

Buyske2

919

977

NR

3.9

132

NR

5.8

2(28)

00

0NR

Basso

30

2000

9NR

NR

NR

NR

40

00

022

.8a

ChoiYB31

2000

32NR

4.8

NR

NR

5.9

1(3)

01(3)

0NR

Hepworth

32

2000

99(100)

NR

NR

NR

3a2(22)

00

NR

NR

Avital33

2003

72(29)

NR

180a

NR

3a0

02(29)

NR

NR

Walsh

18

2003

14NR

3.8

186

NR

3.8

00

00

16.2

Hindm

arsh

34

2005

3022

(73)

4.5

7419

65.0

7(23)

00

2(7)

18a

Bédard3

520

0614

14(100)

4.1

175

NR

4.6

2(14)

00

1(7)

46.5

Berindoague

36

2006

2218

(82)

5.6

NR

NR

6a1(5)

00

1(5)

32a

Granger

37

2006

125(42)

4.1

169

NR

2.3

00

00

19

Lai4

2006

2828

(100)

3.4

191

NR

6.7

00

00

43.3

Mochizuki

38

2006

1210

(83)

2.7

100

07

00

00

26a

Nov

itsky

520

0650

50(100)

4.4

135

853.8

00

04(8)

36

Otani

620

0635

35(100)

4.3

NR

NR

7.2

00

00

53a

ChoiSM

720

0723

23(100)

4.2

104

395.2

00

00

61

Catena3

920

0821

21(100)

4.5

151

101

4.8

00

0NR

35

Hiki16

2008

76(86)

4.6

169

77.4

00

NR

NR

NR

Nakam

ori40

2008

2525

(100)

5.0

165

506.6

00

02(8)

37

Privette

15

2008

129(75)

5.1

234

108

4.6

00

00

NR

Sexton8

2008

6161

(100)

3.8

152

973.9

1(2)

1(2)

1(2)

3(5)

15

Wilh

elm

41

2008

9362

(67)

2.6

93NR

7.5

6(7)

04(4)

039

.5a

Hwang1

220

0963

41(65)

NR

8633

5.3

00

00

15

Silb

erhu

mer

42

2009

2222

(100)

3.5

NR

NR

7.8

4(18)

00

030

Tabrizianb

920

0955

55(100)

3.5

143

138

67(13)

1(2)

3(5)

4(7)

41

Goh

10

2010

1411

(79)

3.1a

150a

0a4.5a

1(7)

00

08a

Sasaki43

2010

4537

(82)

3.2a

100a

5a7a

1(2)

00

074

a

Warsi44

2010

2217

(77)

3.0

80NR

3a1(5)

00

012

a

Ke4

520

1084

43(51)

NR

6386

5.6

00

00

51

Karakousisc11

2011

4040

(100)

3.6a

96a

25a

4a13

(25)

c0

01(3)

28a

Lee

13

2011

5035

(70)

2.9

153

NR

5.7

1(2)

00

021

Ma4

620

1156

56(100)

3.0a

90a

55a

7.0

00

00

21.5a

Ngu

yen4

720

1144

31(70)

NR

9733

2.6

00

1(2)

1(2)

51.6

J Gastrointest Surg

viscera including the distal pancreas and spleen. Com-plexity related to multivisceral resection may influencethe likelihood of higher-grade morbidity seen with con-versions and open surgery, although this may be simplyrelated to the effect of laparotomy. Potential advantagesof laparoscopy include reduced incision size, pain, in-fection risk, and hernia formation, which may be worthan attempt at laparoscopy followed by conversion ifunsuccessful. Of interest, patients converted to opensurgery had morbidity and length of stay that wasintermediate between laparoscopy and open, perhapsreflecting the fact that none of the conversions wereemergent in nature and suggesting that outcomes fol-lowing conversion were not necessarily inferior to opensurgery.

Important to this study is the finding of excellentperioperative outcomes in the form of hospital lengthof stay, operative time, and estimated blood loss afterlaparoscopic resection. We are first to report complica-tions after resection of gastric submucosal neoplasmusing a validated grading system,20 which clearly dem-onstrates the value of laparoscopic resection. However,a technical failure occurred after laparoscopic resectionin a patient with an antral tumor leading to gastricoutlet obstruction. Consideration should be given fordistal gastrectomy either by laparoscopic or open tech-niques for large tumors near the antrum and pylorus toavoid narrowing the residual stomach.

Moreover, with regard to oncologic outcomes, we haveshown that this may be related more to tumor biology thantechnical considerations. Our finding that mitotic index waspredictive of recurrence is supported by prior studies,25,57 aswith the pattern of recurrence favoring hepatic metastasis.53

Survival analysis showed no significant differences in sur-vival between laparoscopic and open cohorts when con-trolled for biologic variables, but our data are limited byshort follow-up, particularly in the laparoscopic cohort.Among those patients who recurred, there was a mean timeto recurrence of three years for the laparoscopic group andtwo years for the open group. However, Miettinen et al.report that recurrences may occur over 20 years after resec-tion, suggesting caution at extrapolating oncologic out-comes in the short term.25

Conclusions

Laparoscopic resection for gastric submucosal neoplasms isclearly feasible, with excellent perioperative outcomes and areduction in morbidity, length of stay, blood loss, and oper-ative time. Concerns arise in the use of laparoscopy forposterior tumors, which may be mitigated by additionalexpertise in laparoscopic intracorporeal suturing, allowingT

able

7(con

tinued)

Autho

rYear

NGISTs

n(%

)Size(cm)

n(%

)ORtim

e(m

in)

EBL

(mL)

LOS

(d)

Conversions

n(%

)Mortality

n(%

)Reoperatio

nsn(%

)Recurrences

n(%

)Follow-up

(mon

ths)

Ryu

48

2011

2016

(80)

2.4

84NR

4.7

00

00

NR

DeVog

elaere

14

2012

3131

(100)

4.4

9912

28.5

01(3)

00

56.3

Kakeji49

2012

1810

(56)

3.5

128

259.8

00

1(6)

046

.1

Ganai

2012

7957

(72)

4.4

142

663.6

8(10)

1(1)

2(3)

4(5)

21

Total

371174

902(77%)

3.7±0.1

118±7

70±12

5.5±0.3

4.9%

0.3%

1.3%

2.1%

35±3

GISTs

gastrointestinal

stromal

tumors;ORop

erative;

EBLestim

ated

bloo

dloss;LOSho

spitalleng

thof

stay;NRno

trepo

rted

aMedianvalueisrepo

rted;allothervalues

representmeans

bDataalso

comprised

anadditio

nal21

patientsun

dergoing

laparoscop

icmanagem

entof

smallbo

wel

GIST

cCon

versions

(n013

)areno

tinclud

edelsewhere

indata

asrepo

rted

byauthors

J Gastrointest Surg

for transgastric resection. Moreover, conversions were asso-ciated with tumors greater than 8 cm in size, suggesting anopen technique may be more appropriate with larger tumors.The biological behavior of GISTs may ultimately be morepredictive of long-term outcome than the technique used toresect them, but the principles of oncologic surgery, favor-ing avoidance of capsular disruption and resection with agrossly negative margin should be maintained.

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Discussant

Dr. Marcovalerio Melis (New York, NY): In the lastdecades we have learned that minimally invasive (MIS)gastric surgery is associated with reduced blood losses anddecreased perioperative complications when performed forweight loss, gastroesophageal disease or adenocarcinoma.

However MIS resection of submucosal gastric neoplasmspresents unique challenges (e.g. size of tumors, risk ofintraoperative rupture, occasional need for en-bloc resections).

You present a relatively large series of MIS gastric resec-tions for submucosal tumors, but your study is limited by itsretrospective design and by obvious selection bias.

Smaller tumors were mostly removed with laparoscopicwedge resections and larger tumors were more likely torequire neoadjuvant treatment, open surgery, and multi-visceral resections. Therefore, it did not come as a surprisethat open cases were associated with longer operative times,higher blood losses, and increased post-op complications.

My question is: based on what you learned from yourexperience, how will you select patients for laparoscopyfrom now on?

It would appear safe to say that open surgery should beoffered whenever multivisceral resection appears necessary.

What about size? Currently, the most permissive guide-lines discourage laparoscopy for GIST>5 cm. Probably, thisrecommendation will be overcome in the next few years,however I am still not convinced that we should expand theindications for MIS to tumors up to 8 cm, solely because inyour multivariate analysis you found a significant differencein median size between laparoscopic and converted cases.

Thank you.

Closing Discussant

Dr. Sabha Ganai: Thank you, Dr. Melis, for your com-ments and questions. Regarding selection for laparoscopy,we favor an approach where laparoscopic resection isattempted as long as imaging characteristics and anatomical

J Gastrointest Surg

location of the lesion appear favorable. While 75 % ofpatients in our series underwent an attempt at laparoscopicresection, this significantly increased from 50 % in theinitial two years to 89 % in the latter two years of the series.This may be from an overall increase in both expertise andutilization of laparoscopy during the time interval of nearlya decade. This must be taken with consideration that forlaparoscopic excision of posterior lesions, nearly a thirdrequired transgastric approaches, requiring some facilitywith intracorporeal suturing techniques. We feel that withawareness of the limitations that may be posed by lesionslocated near the GE junction as well as at the antrum andpylorus, laparoscopy is still a reasonable method to excise amajority of gastric submucosal neoplasms, with good peri-operative outcomes. Moreover, conversions were mainlysecondary to lack of progress, and while they had a compli-cation profile as expected from a laparotomy, these patientsdid not necessarily fare any worse than patients who under-went open resection. One may argue that unless imagingcharacteristics suggest a substantial tumor or multivisceralinvolvement, minimal additional harm may be posed bymaking an attempt at laparoscopic resection, with a decisionto convert to be an indication of sound judgment.

Regarding the role of size on conversions, we included inour multivariate model posterior location and multivisceralinvolvement, after excluding other features that did notachieve significance on univariate analysis such as

requirement for an anastomosis, BMI, and prior laparotomy.Only size greater than 8 cm remained an independent pre-dictor of conversion. It is likely that tumors involving otherorgans were selected to be addressed primarily by opentechniques, so multivisceral involvement may not have beenas important as size was in predicting the likelihood ofconversion from laparoscopy secondary to selection bias.While some guidelines discourage laparoscopy for GISTslarger than 2–5 cm, a quarter of those laparoscopicallyresected in this series were larger than 5 cm. No lesionshad tumor rupture during handling. While we mention thatsize greater than 8 cm is predictive of conversion to open,which may not necessarily be of great consequence, itshould come with an awareness that there may be a needfor distal pancreatectomy and splenectomy in some of theselesions. This may be an important consideration for preop-erative planning, especially for surgeons with limited exper-tise in complex oncologic resections. Whether it may bemore prudent to limit laparoscopic resection to tumors lessthan 5 cm, I can only say that there may be a benefit gainedfrom favoring laparoscopy in terms of perioperative out-comes if resection can be achieved in an oncologicallysound fashion, but once again, this is based on a retrospec-tive series with considerable selection bias. Our data doessuggest that tumor biology may be of greater importancethan the method of resection when it comes to oncologicoutcomes.

J Gastrointest Surg