the laparoscopic roux - en - y gastric bypass ( lrgb ) is currently the preferred procedure in the management of severely obese patients . with increasing numbers of operated patients , late complications
internal hernias are the main cause of late postoperative morbidity , causing abdominal discomfort and sometimes leading to bowel obstruction .
we present a large series from a single team of surgeons with a high internal follow - up rate .
the closure of mesenteric defects involves the suturing or other manipulation of the small bowel mesentery with the risk of haematomas and disturbed anatomy of the enteroanastomosis . against the background of our previous experience
, we wanted to test whether a new , simple approach to closing the mesenteric defects could be introduced without a high cost in short - term complications .
aleris hospital in oslo , norway , and aleris obesitas skne in kristianstad , sweden , are private clinics with dedicated bariatric units , using the same rotating team of surgeons .
indications for surgery were the same as generally accepted as a good standard for bariatric surgery ( european guidelines).table 1patient demographics  2005may 2010june 2010june 2011total number of patients2,4721,630age at operation42 ( 1774)41 ( 1769)bmi at operation43 ( 2968)42 ( 2962)fu time ( months)23 ( 764)follow - up at the time of writing insufficient for analysis follow - up at the time of writing insufficient for analysis previous policy during the period from september 2005 until june 2010 , we performed , in total , 2,472 lrgb without closing the mesenteric defects .
new policy from 1 june 2010 to 1 june 2011 , we performed 1,630 lrgb and closed the mesenteric defect in all our patients with our new technique .
five ports were used : two 5-mm and two 12-mm ports for instruments and one 10-mm for the camera ( fig .  1 ) .
1position of trocars for gastric bypass position of trocars for gastric bypass the first part of the operation was the same in all cases .
a very small gastric pouch was created and the bowel brought up , first as an omega loop in an antecolic and antegastric fashion . following linear stapling of the anastomoses and division of the omega loop , the last step was testing the integrity of the gastrojejunostomy by inflating it with methylene - blue - dyed saline via a nasogastric tube .
the closing procedure was started after dividing the omega loop , with the patient still in the reverse trendelenburg position .
petersens defect the endo universal 4.8  mm stapler ( autosuture ) was inserted via trocar # 4 ( 12  mm ) . with gentle manoeuvres ,
a pair of graspers was used to expose the petersen 's defect by lifting the transverse mesocolon ( fig .  2 ) .
we closed the petersen 's defect from the root of the mesentery of the roux limb and transverse colon up to the transverse colon itself . to avoid vascular injury ,
2closure of petersen s space closure of petersen s space jejunal mesenteric defect the assistant pulled up the end of the duodenal limb in order to expose properly this mesenteric defect as shown in fig . 
we used the same type of laparoscopic stapler via trocar # 4 also for the closing of this defect .
we took care to avoid kinking of the roux - limb at level of the jejuno-jejunostomy.fig .
3closure of jejunal mesenteric defect closure of jejunal mesenteric defect data from all patients during the study period were prospectively collected in a proprietary database .
the closing procedure was started after dividing the omega loop , with the patient still in the reverse trendelenburg position .
petersens defect the endo universal 4.8  mm stapler ( autosuture ) was inserted via trocar # 4 ( 12  mm ) . with gentle manoeuvres ,
a pair of graspers was used to expose the petersen 's defect by lifting the transverse mesocolon ( fig .  2 ) .
we closed the petersen 's defect from the root of the mesentery of the roux limb and transverse colon up to the transverse colon itself . to avoid vascular injury ,
2closure of petersen s space closure of petersen s space jejunal mesenteric defect the assistant pulled up the end of the duodenal limb in order to expose properly this mesenteric defect as shown in fig . 
we used the same type of laparoscopic stapler via trocar # 4 also for the closing of this defect .
we took care to avoid kinking of the roux - limb at level of the jejuno-jejunostomy.fig .
data from all patients during the study period were prospectively collected in a proprietary database .
we performed 2,472 lrgb in our two hospitals between september 2005 and june 2010 ( table  1 ) .
one hundred seventeen patients ( 100 women and 17 men ) with a mean age of 41  years ( range , 2267  years ) developed an internal hernia ( 4.7% ) at a mean interval after lrgb of 13 ( range , 443  months ) .
the mean bmi the time of internal hernia was 27 ( range , 1838  kg / m ) . in 46 ( 39% ) cases ,
the internal hernia was at the jejuno - jejunostomy ; 28 ( 24% ) cases had an internal hernia at petersens defect .
forty - three patients were found only to have a mesenteric defect without overt herniation of bowel .
the diagnosis of internal herniation was confirmed laparoscopically and the reduction of the hernia and closure of the mesenteric defects undertaken with a non - absorbable running suture .
seven were operated on by open surgery ; four patients needed bowel resections ( 70300  cm ) because of severe ischemia .
a life - table analysis was performed , which estimates an 11.1% 5-year incidence of clinically significant internal hernia requiring operation ( fig . 
4a survival function diagram drawn using the life - table method demonstrates well the relation of internal hernia occurrence to post - operative time .
the analysis is based on 1,671 patients operated in oslo with lrgb from 2006 to mid 2010 .
one hundred four ( 6.2% overall ) cases had been reoperated for confirmed , clinically significant internal hernia .
this diagram illustrates how the internal hernia cases start to occur 3  months post - operatively and seem to be uniformly frequent through the first 3  years . internal hernia operation - free survival by this method
is estimated to be 88.9% at the end of a 5-year follow - up a survival function diagram drawn using the life - table method demonstrates well the relation of internal hernia occurrence to post - operative time .
the analysis is based on 1,671 patients operated in oslo with lrgb from 2006 to mid 2010 .
one hundred four ( 6.2% overall ) cases had been reoperated for confirmed , clinically significant internal hernia .
this diagram illustrates how the internal hernia cases start to occur 3  months post - operatively and seem to be uniformly frequent through the first 3  years . internal hernia operation - free survival by this method is estimated to be 88.9% at the end of a 5-year follow - up between june 2010 and june 2011 , we operated 1,630 consecutive lrgb patients where the mesenteric defects were closed using the endohernia stapling device ( endo universal 4.8  mm , autosuture ) .
stopwatch timing in 20 cases showed an average time used for closing both mesenteric defects of 1  min and 49  s ( 1:20 to 2:50 ) .
four patients ( 0.2% ) in the group with mesenteric closure have been re - operated on because of bowel obstruction at the entero - anastomosis directly related to the closure of this mesenteric defect .
all were early in the series and operated within 4  days of the primary operation .
twenty - two patients operated by this method have been re - operated on later for other reasons , and in all cases , the two mesenteric defects were examined and complete closure ascertained and documented ( fig .  5).fig .
5jejunal mesenteric defect ( left ) and petersen`s defect ( right ) 11  months after closure with ms endohernia stapling device jejunal mesenteric defect ( left ) and petersen`s defect ( right ) 11  months after closure with ms endohernia stapling device
we performed 2,472 lrgb in our two hospitals between september 2005 and june 2010 ( table  1 ) .
one hundred seventeen patients ( 100 women and 17 men ) with a mean age of 41  years ( range , 2267  years ) developed an internal hernia ( 4.7% ) at a mean interval after lrgb of 13 ( range , 443  months ) .
the mean bmi the time of internal hernia was 27 ( range , 1838  kg / m ) . in 46 ( 39% ) cases ,
the internal hernia was at the jejuno - jejunostomy ; 28 ( 24% ) cases had an internal hernia at petersens defect .
forty - three patients were found only to have a mesenteric defect without overt herniation of bowel .
the diagnosis of internal herniation was confirmed laparoscopically and the reduction of the hernia and closure of the mesenteric defects undertaken with a non - absorbable running suture .
seven were operated on by open surgery ; four patients needed bowel resections ( 70300  cm ) because of severe ischemia .
a life - table analysis was performed , which estimates an 11.1% 5-year incidence of clinically significant internal hernia requiring operation ( fig . 
4a survival function diagram drawn using the life - table method demonstrates well the relation of internal hernia occurrence to post - operative time .
the analysis is based on 1,671 patients operated in oslo with lrgb from 2006 to mid 2010 .
one hundred four ( 6.2% overall ) cases had been reoperated for confirmed , clinically significant internal hernia .
this diagram illustrates how the internal hernia cases start to occur 3  months post - operatively and seem to be uniformly frequent through the first 3  years . internal hernia operation - free survival by this method
is estimated to be 88.9% at the end of a 5-year follow - up a survival function diagram drawn using the life - table method demonstrates well the relation of internal hernia occurrence to post - operative time .
the analysis is based on 1,671 patients operated in oslo with lrgb from 2006 to mid 2010 .
one hundred four ( 6.2% overall ) cases had been reoperated for confirmed , clinically significant internal hernia .
this diagram illustrates how the internal hernia cases start to occur 3  months post - operatively and seem to be uniformly frequent through the first 3  years . internal hernia operation - free survival by this method is estimated to be 88.9% at the end of a 5-year follow - up
between june 2010 and june 2011 , we operated 1,630 consecutive lrgb patients where the mesenteric defects were closed using the endohernia stapling device ( endo universal 4.8  mm , autosuture ) .
stopwatch timing in 20 cases showed an average time used for closing both mesenteric defects of 1  min and 49  s ( 1:20 to 2:50 ) .
four patients ( 0.2% ) in the group with mesenteric closure have been re - operated on because of bowel obstruction at the entero - anastomosis directly related to the closure of this mesenteric defect .
all were early in the series and operated within 4  days of the primary operation .
twenty - two patients operated by this method have been re - operated on later for other reasons , and in all cases , the two mesenteric defects were examined and complete closure ascertained and documented ( fig . 
5jejunal mesenteric defect ( left ) and petersen`s defect ( right ) 11  months after closure with ms endohernia stapling device jejunal mesenteric defect ( left ) and petersen`s defect ( right ) 11  months after closure with ms endohernia stapling device
the clinical presentation of internal hernia ranges from intermittent pain , often in the left upper abdomen through more constant abdominal pain , with or without nausea and vomiting to severe , acute abdominal pain.2 a certain diagnosis can most often only be made by laparoscopy . in case of uncertain abdominal pain in patients with lrgb ,
our policy is to perform gastroscopy to exclude pouch ulcers and ultrasound examination , revealing cholecystolithiasis . whenever a laparoscopy is indicated in these patients ,
internal hernia may often co - exist with ulcer or gallstones , which can lead to diagnostic error .
a high suspicion of internal hernia is in order , even in the presence of other possible causes of pain such as pouch - ulcer .
it seems that the laparoscopic approach is associated with a higher risk of internal hernias than that of open gastric bypass , due to less postoperative adhesions .
the reported incidence of internal hernia after lrgb ranges widely , from 0.2% to 9%.27 the incidence also depends on the surgical method , with the retrocolic route of the alimentary - limb causing more internal hernias than the antecolic route.4,8 primary closure of the mesenteric defects seems to reduce the incidence of internal hernia5 , but can also be associated with complications . by suturing the mesentery ,
closure of the mesenteric defects can also result in increased rate of obstruction at the entero - anastomosis caused by adhesion or rotation of the anastomosis.9 our present cumulative incidence of internal herniation of 4.7% lies within the published limits.7,10 however , we are convinced this incidence is underestimated because the duration of the follow - up is still limited .
a lifetime risk in excess of the estimated 5-year incidence of 11.1% is what can be expected by a longer follow - up ( fig . 
4 ) . internal hernia is a potentially dangerous complication , causing mortality in one of our patients .
therefore , when extracting this significant fact from our database in june 2010 , we decided to commence primary closure of both mesenteric defects in all our patients . our team is currently performing 1,700 lrgb per year ( aleris hospital oslo and aleris obesitas skne ) , thus secondary closure of the defects in 11.1% of patients will demand a great deal of resources . by using the endohernia device
, we did not have to change the placement of our trocar ports , and our operation time was only slightly increased ( 23  min ) .
mean time from primary operation without mesenteric closure to reoperation for internal hernia was 13  months .
the hernia - free survival diagram indicates that the incidence of clinically significant herniations continues from about 3  months post - op through at least the first 3  years .
in our view , it is very important at this stage to present our early observations and experience with the methodology as it is already gaining wide popularity .
we will certainly report the results when follow - up duration has become appropriate for analysis .
however , the primary closures with our method have hitherto only resulted in four reoperations due to kinking of the enteroanastomosis and no mesenteric haematomas .
our experience is in line with increasing evidence from several centres that the mesenteric defects should be closed primarily .
we can not , however , at this moment , present long - term results on the efficacy of this closure method , but the results so far are promising .
 backgroundbowel obstruction due to internal hernia is a well - known complication of laparoscopic roux - en - y gastric bypass ( lrgb ) . 
 increasing evidence supports primary closing of the mesenteric defects , but controversy continues about surgical technique of systematic closure . 
 this paper reviews our experience with internal hernia after lrgb and describes a new method of preemptive closure of the mesenteric defects.material and methodstwo thousand four hundred seventy - two consecutive patients undergoing lrgb from september 2005 to june 2010 were entered into our prospective longitudinal database . 
 the mesenteric defects were not closed . 
 patients entered a 5-year follow - up program , and all who subsequently presented with internal hernia were analyzed . 
 a further 1,630 patients operated on in the last 12  months were subjected to our new technique of closing the defects ; data were entered in our own database as well as in the scandinavian quality registry . 
 follow - up time for these patients is limited.resultsin the first group , 117 patients developed an internal hernia ( 4.7% ) at a mean interval after lrgb of 13 ( range , 443  months ) . 
 four patients needed bowel resections because of severe ischemia . 
 there was one death associated with complication of the internal hernia . in the primary closure group , 
 four patients early in the series had reoperations for kinking of the enteroanastomosis . 
 there have been no mesenteric haematomas encountered.conclusionsinternal hernia should be ruled out in patients with previous lrgb and abdominal pain . our technique for primary closing of the mesenteric defects seems to be safe and is so far promising . 
Introduction
Patient Material
Operative Methods
Technique for Primary Laparoscopic Closing of Mesenteric Defects
Statistics
Results
Non-closure of Mesenteric Defects
Closure of Mesenteric Defects by Our New Technique
Discussion
Conclusion