1198 Obesity Surgery, 14, 2004 © FD-Communications Inc.

Obesity Surgery, 14, 1198-1202

Background: A prospective comparison was con-ducted of extraluminal bleeding following gastrictransection with or without staple-line reinforcementby dehydrated bovine pericardium (Peri-Strips Dry® -PSD) during laparoscopic Roux-en-Y gastric bypass(LRYGBP).

Methods: From January 2001 to September 2003, 98consecutive morbidly obese patients underwentLRYGBP. Patients were randomly allocated to 2groups according to the use (Group A, n= 50) or not(Group B, n= 48) of Peri-Strips Dry®. In both groups,mortality, intra- and postoperative early and late com-plications, operating-time, number of hemostaticclips used, blood transfusion and any specific eventdirectly related to the prosthetic material wereprospectively evaluated. Data were expressed asmean ± SD except as otherwise indicated. Statisticalanalysis was done by means of Student t-test andFisher exact test. P-value cut off for statistical signifi-cance was set at 0.05.

Results: Intra- and postoperative mortality wereabsent. Intra-operative methylene blue test was posi-tive in 6/48 (12.5%) of Group B patients (P<0.001).Overall laparotomic conversion was 3/98 patients(3.1%). One/48 Group B patient was convertedbecause of unsatisfactory exposure and one for lin-ear stapler misfire. One/50 Group A patients was con-verted for short gastric vessels bleeding during dis-section. No patients were re-operated or transfusedbecause of extraluminal bleeding. Mean number ofclips used was significantly lower in Group A patients(5 vs 23, P<0.001). The operating-time was signifi-

cantly less in Group A patients (120±60 vs 220±100minutes, P<0.01).

Conclusions: Gastric staple-lines reinforced withPeri-Strips Dry® result in a significant reduction in thenumber of Endo-clips used and prevent bleeding. Adry operating field was obtained, and operating-timewas significantly reduced. No adverse events couldbe related to the use PSD.

Key words: Morbid obesity, gastric bypass, bleeding, lin-ear stapler, laparoscopy, bovine pericardium strips

Introduction

Roux-en-Y gastric bypass (RYGBP) is currently themost common bariatric operation worldwide, withlaparoscopic gastric banding being the preferredoperation outside the USA.1 In North Americawhere RYGBP is the most common bariatric proce-dure, the number of centers performing it by thelaparoscopic approach is still limited because of thecomplexity of the operation. However, in Europe theappreciation of RYGBP when performed bylaparoscopy (LRYGBP) is steadily growing. Theprocedure is based mainly on the use of the endo-scopic linear stapler to transect the stomach and cre-ate a small isolated gastric pouch.2 Gastric transec-tion margins usually bleed. While in open surgery,oversewing the margins can be easily accomplishedin a reasonable amount of time, this technical prob-

The Use of Bovine Pericardial Strips on LinearStapler to Reduce Extraluminal Bleeding duringLaparoscopic Gastric Bypass: ProspectiveRandomized Clinical Trial

Luigi Angrisani, MD, ChM; Michele Lorenzo, MD, PhD; Vincenzo Borrelli,MD; Monica Ciannella, MD; Uberto Andrea Bassi, MD; Paolo Scarano,MD

ASL NA1 - Laparoscopic and Minimally Invasive Surgical Unit, S. Giovanni Bosco Hospital and“Federico II” University, Naples, Italy

Reprint requests to: Dott. Luigi Angrisani MD, ChM, PiazzaVittoria 7, 80121 Naples, Italy.E-mail: luigiangrisani@chirurgiaobesita.it

lem remains consistent in laparoscopy.2-4

In trying to overcome this technical problem, anattempt was made to buttress the linear stapler dur-ing LRYGBP by using a non-absorbable biologicaltissue derived from dehydrated bovine pericardium(Peri-Strips Dry® - PSD). This product was origi-nally introduced in 1994 to reduce air-leaks duringlung resection, and its benefit has been largelyproved in lung volume reduction surgery over thepast 10 years.5,6 Recently, Shikora et al7 demon-strated the absence of acute leak by the use of Peri-Strips Dry® on the gastric staple-lines of 250 non-randomized morbidly obese patients undergoingLRYGBP. This product received CE mark clearancefor bariatric indication in 1999 and FDA clearancein 2000. The current study is a prospective compar-ison of results obtained in extraluminal bleeding fol-lowing gastric transection with or without staple-line reinforcement by Peri-Strips Dry® duringLRYGBP.

Methods

Patients

From January 2001 to September 2003, 98 consec-utive morbidly obese patients were considered forLRYGBP. Patients were randomly allocated intotwo groups according to the use (Group A, n=50) ornot (Group B, n= 48) of dehydrated bovine peri-cardium. In both groups, mortality, intra-operativeand postoperative early and late complications,operating-time, number of hemostatic clips used,blood transfusion and any specific event directlyrelated to the prosthetic material were prospectivelyevaluated. Intra-operative blood loss was notrecorded by blood suction, because of the use of anirrigation system and laparoscopic swabs. Bleedingwas defined as any intra-operative event whichrequired attempts or particular manoeuvers toachieve hemostasis.

Materials

Endo-GIA® (35-45-60 mm) blue cartridge (3.5 mm)were manufactured by USSC (Norwalk, CT, USA).The 25 PCEEA was from Tyco. Balloon Bougie®

was from Inamed (Santa Barbara, CA, USA).

Bovine dehydrated pericardium, Peri-Strips Dry®,were manufactured by Synovis Surgical Innovations(St. Paul, MN, USA). Endo-Clip® ML and L 10 mmwere from USSC (Norwalk, CT, USA). Ligaclip® Mand L 10 mm and Ultracision® 5 mm were fromEthicon Endo-Surgery (Cincinnati, OH, USA).Ultra Shears® 5 mm were from USSC TycoHealthcare (Norwalk, CT, USA). PDS LapraTy®

and Blake Drains® 19-Fr were from Johnson &Johnson (Cincinnati, OH, USA)

Surgical Technique

Patients were positioned in reverse Trendelenburglithotomy position. Closed CO2 pneumoperitoneumwas created, and six trocars were inserted. The gas-tric bougie was trans-orally positioned in the stom-ach. The balloon was inflated with 30 ml of salinesolution, and was retracted backward by the anes-thesiologist to reach the cardio-esophageal junction.Dissection was started at the equator of the balloonin the peri-gastric space between the neurovascularbundle of Latarjet and lesser curvature of the stom-ach using the harmonic scalpel. The retro-gastricspace below the bursa omentalis was entered, andgastric transection was performed by multiple linearstapling (reinforced by PSD® in Group A patients),fired in sequence up to the angle of His.

In Group A patients, PSD was mounted on the lin-ear stapler by using a film of adhesive hydrogel(PSD gel) to re-hydrate the strips and create a bondbetween the strips and the jaws of the linear stapler.In both Group A and B patients, bleeding pointswere controlled with the application of hemoclips,while any malformed staple-lines were over-sewn.In Group B patients, diathermy was also used toachieve hemostasis. The flip-top anvil of a 25-mmcircular stapler was advanced trans-orally into andthrough the proximal gastric pouch, using a modi-fied naso-gastric tube anvil apparatus. The Rouxlimb was constructed by transecting the small bowel30 to 50 cm distal to the ligament of Treitz. A ser-vice jejunotomy on the alimentary limb was createdand the circular stapler was introduced transabdom-inally, and was advanced into the lumen of thejejunum to create an ante-colic ante-gastric end-to-side gastro-jejunostomy. The service jejunotomywas closed with a PSD-reinforced 60-mm linear sta-pler in Group A patients.

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Gastro-jejunostomy leak was tested by injecting40-60 cc of methylene blue through the naso-gastrictube previously positioned into the alimentary limbtemporarily clamped. Test positivity was consideredby the presence of methylene blue extraluminally.Side-to-side jejuno-jejunostomy was performed bya 45-mm linear stapler through the jejunotomy ser-vice, 100-150 cm distal to the gastro-jejunostomy.The anastomosis was completed by 2-0 PDS contin-uous sutures.

Statistical Analysis

Randomization was performed according to Lisontables.8 Data were expressed by mean ± standarddeviation except as otherwise indicated. Student t-test and Fisher exact test were used for statisticalanalysis, and P<0.05 was considered significant.

Results

Patient characteristics of both Groups were similarand without significant differences (Table 1). Intra-and postoperative mortality was absent. Intra-opera-tive methylene blue test was positive in 6/48(12.5%) of Group B patients (P<0.001), and in allbut one case 2-0 Vicryl® interrupted stitches wereinserted to control the leak. Overall laparotomicconversion was 3/98 patients (3.1%). One/50 GroupB patient with a posterior leak was converted to a

laparotomy because of unsatisfactory exposure, andone other patient was converted to a laparotomy forlinear stapler misfire. Conversion to a laparotomywas also required in 1/50 Group A patients for shortgastric vessels bleeding during dissection of the gas-tric fundus. No patients were re-operated or trans-fused because of extraluminal bleeding. The meannumber of clips used was significantly lower inGroup A patients (5 vs 23, P<0.001). The operating-time was significantly less in Group A patients(120±60 vs 220±100 minutes, P<0.01). Theseresults are presented in Table 2. No adverse clinicalor surgical event could be related to the use of PSD.Late gastrointestinal intra- or extraluminal bleedingwas not observed in both groups.

Discussion

The current endoscopic linear staplers by Ethiconand Tyco evolved from the laparotomic GIA staplersthat were introduced into clinical practice at the endof the 1970s. These modern instruments are flexi-ble, rotate 360˚, and come in different cartridgelengths (30 mm, 35 mm, 45 mm, 60 mm) and dif-ferent staple sizes (white 2.5 mm, blue 3.5 mm andgreen 4.8 mm) according to the thickness of the tis-sue to be transected. The Ethicon stapler divides thetissue between two lines of staples, while Tycoleaves three lines of staples on each side. Because oftheir different mechanism of transection with only

Table 1. Patient characteristics

Age Sex BMI - kg/m2 % Excess Weight(mean±SD; range) (M/F) (mean±SD; range) (mean±SD; range)

Group A 36.1±11.5; 19-58 12/38 49.3±4.9; 37-59 97.6±15.5; 45.1-150Group B 35.8±10.8; 20-60 10/38 50.0±3.7; 38-58 98.1±14.7; 45.9-152

Table 2. Patient outcome

Clips used Leak Operating-time Laparotomic conversion(mean±SD; range) (methylene blue test) (mean±SD; range)

Group A 5±1; 0*-7 0/50 120±60 # 1/50 (2.0%)+Group B 23±8; 10-33§ 7/48 (12.5%) 220±100 2/48 (4.2%)

* = in five patients; § = P<0.001; # = P<0.01; + = P<0.01.

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two lines of staples, the Ethicon endocutter 45 flexwas used in the authors’ experience in only fivepatients (three with PSD). To avoid study bias, theywere not included in the present analysis. The lim-ited case number does not allow us to make an eval-uation of this device.

After 20 years of evolution, the modern endo-scopic linear staplers share, in common with the oldtraditional laparotomic instrumentation, the extra-luminal bleeding on the transection staple-lines.4,9-11

In open surgery, the amount of blood loss sec-ondary to linear-stapler visceral transection is gen-erally minimal; it can be ignored and treated byswab compression which stimulates spontaneouspatient self-coagulation. In a number of cases, it isnecessary to overstitch the transected staple-line.Ischemia from this manoeuver in the transectionmargins remains a potential sequel.

On the contrary, in laparoscopy, a bloodless oper-ating field is mandatory. Bleeding decreases the def-inition of the image on laparoscopic view. Underthese circumstances sharp dissection is difficult dueto the continuous loss of exposere of the operativefield, and suction, irrigation, and camera cleansingare often required, prolonging operating-time.

Although diathermy and laparoscopic titaniumclips are commonly used to control the bleeding ofthe transected gastric pouch during LRYGBP, theireffect on the strength of the staple-lines has not beentested in experimental or clinical studies. Stitchingwhich is used in open surgery would probably rep-resent the method of choice, but is not easy to per-form laparoscopically. All these techniques aretime-consuming, and potentially lead to postopera-tive life-threatening leaks and perforation.

In the present study, the mean number of titaniumclips used to control extraluminal bleeding (23±8)on the gastric pouch in the group of patients withoutPSD reinforcement (Group B) corresponds nicelywith the results reported by Champion andWilliams12 in a prospective study (21±7 EndoGIAand 30±9 ETS). The use of PSD in group A patientslowered the mean number of clips to 5±1 (P<0.001).Although intra-operative blood loss was not directlymeasured in this study, the reduced number of clipsapplied relates directly to the reduced number ofbleeding episodes which required additional surgi-cal manoeuvers for hemostasis. Therefore, bleedingwas obviously non-existent when using PSD.

The operating-time was also significantly reducedin this group of patients because of the reducednumber of surgical manoeuvers to identify and con-trol the bleeding source. Interestingly, in the presentstudy, the intra-operative methylene blue test waspositive in 12.5% of group B patients where theanvil of the circular stapler was passed through thestaple-line of the gastric pouch according a modi-fied Knight and Griffen anastomotic technique. Inthe group A patients who had PSDs, the intra-oper-ative positive methylene blue test was 0, because theanvil was never passed through the staple-line, andthe anastomosis was performed on the anterior orthe posterior wall of the gastric pouch. The knife ofthe circular stapler is not able to cut safely throughthe Peri-Strip Dry® and the tissue is too thick for thestaples.

In conclusion, Peri-Strips Dry® can be safelyapplied to linear staplers for LRYGBP. The benefitof PSD reinforcement of the gastric staple-lines toprevent bleeding was demonstrated by a significantreduction in the number of Endo-clips used. As aconsequence of less staple-line bleeding, a dry oper-ating field was obtained. The extra time required toidentify a bleeding source and control it was saved,and the total operating-time was significantlyreduced.

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(Received July 3, 2004; accepted August 17, 2004)