REVIEW ARTICLE ANZJSurg.com
Wrapping in pancreatic surgery: a systematic review Jose M. Ramia, Roberto de la Plaza, Farah Adel, Carmen Ramiro, Vladimir Arteaga and Jorge Garcia-Parreño HPB Surgical Service, Department of Surgery, University Hospital of Guadalajara, Guadalajara, Spain
Key words falciform, omental, omentum, pancreas, pancreatoduodenectomy, review, surgery, wrapping. Correspondence Mr Jose M. Ramia, HPB Surgical Service, Department of Surgery, University Hospital of Guadalajara, C/General Moscardó 26, 5-1, Madrid 28020, Spain. Email: [email protected] J. M. Ramia MD, PhD, FACS; R. de la Plaza MD; F. Adel MD; C. Ramiro MD; V. Arteaga MD; J. Garcia-Parreño MD, PhD. Accepted for publication 14 November 2013. doi: 10.1111/ans.12491
Abstract Background: Wrapping in pancreatic surgery involves the use of the omentum or falciform ligament (FL) to wrap the local retroperitoneal vessels, the pancreatojejunal anastomosis or the pancreatic section of distal pancreatectomy. However, there is no clear evidence that wrapping in fact provides benefits. We have performed a systematic review of the literature about this topic. Methods: We conducted a literature search in the PubMed/MEDLINE database (1966–2012) for any language using various combinations of the following terms: wrapping, omental, omentum, pancreas, pancreatoduodenectomy and falciform ligament. Results: We selected 12 articles. Among five series that included a control group, only one obtained a statistically significant reduction in pancreatic fistula (PF) in the wrapping group and other series showed a lower percentage of post-operative haemorrhage in the wrapping group. In the seven series without control groups, a slight decrease in the rate of post-operative bleeding and PF was observed. Conclusions: On the basis of the literature available at present, we cannot recommend the use of wrapping with omentum and/or FL in pancreatic surgery. Prospective randomized studies applying a systematic wrapping technique are needed in order to establish whether its use should be generalized.
Introduction
Material and methods
Pancreatic fistula (PF) and post-operative bleeding are the most serious complications after pancreatic surgery.1–9 Multiple technical modifications have been used in attempts to reduce the incidence of these complications. One of these practices is wrapping, using the omentum or falciform ligament (FL). First described by Moriura in 1994, wrapping in pancreatic surgery involves the use of the omentum or FL to wrap the local retroperitoneal vessels, the pancreatojejunal (PJ) anastomosis or the pancreatic section of distal pancreatectomy (DP). Although popular in Asia, the technique is not in frequent use in Europe or the US.1,2,5,6,9–11 It has two purposes: firstly, to reduce the rate of postoperative haemorrhage and pseudoaneurysms, avoiding the slipping of vascular ligatures due to the action of pancreatic juice,1–4,6,7,12,13 and, secondly, to decrease the rate of PF around the PJ anastomosis or in the DP section, thereby preventing the associated complications.2–4,6,7,11,13 At present, however, there is no clear evidence that wrapping in fact provides benefits. To assess the true value of the technique, we decided to perform a meta-analysis and systematic review of the literature.
We conducted a literature search in the PubMed/MEDLINE database (1966–2012) (National Library of Medicine, Bethesda, MD, USA) for any language using various combinations of the following terms: wrapping, omental, omentum, pancreas, pancreatoduodenectomy and falciform ligament (Table 1). After reading the abstracts, we concluded that only 15 articles were relevant to our research aims. Because of the small number, we checked the references of these articles but did not find more studies on the subject. Among these 15 articles, there were no randomized control trials (Table 2). Two focused on the surgical technique;5,10 two more were written by the same surgical teams,2,13 of which we selected the one that included more patients. Finally, we selected 12 articles,1–4,6–9,11,12,14,15 which form the basis of our research. Five articles compared groups with and without the use of omentum or FL as wrapping,1,3,4,6,9 and the other seven described series of patients in whom some kind of wrapping was performed.2,7,8,11,12,14,15 Seven studies were retrospective1,2,4,6,11,12,15 and five were prospective.3,7–9
© 2013 Royal Australasian College of Surgeons
ANZ J Surg •• (2013) ••–••
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Ramia et al.
Table 1 Key words search Words
Wrapping and omental Wrapping and omentum Wrapping and pancreas Wrapping and pancreatoduodenectomy Wrapping and falciform Falciform and pancreas Falciform and pancreatoduodenectomy Total
Records screened
Full-text articles assessed for eligibility
Studies included
176 123 36 11
7 5 3 7
5 5 2 5
5 16 4
4 5 4
4 5 4
371
35/19†
30/15†
†Excluding repeat articles.
Results After abandoning our initial idea of conducting a meta-analysis due to the absence of randomized trials that could be compared, we conducted a systematic literature review. We grouped the articles by type of wrapping: omentum, FL or both.
Omentum and/or FL Tani et al. conducted a multi-centre retrospective study of 2597 patients who underwent pancreatic surgery. Wrapping with omentum and/or FL was performed in 918 patients. Wrapping patients had a longer operative time, a higher PF rate, more severe fistulas (grades B and C) and more wound infection. Interestingly, the amylase level in the drainage was lower in the group with wrapping. The results obtained with FL were better than those obtained with omentum. The location of the wrapping (vessel protection or peri-anastomotic) did not change the complication rate, which was higher in the group with wrapping in all cases. Wrapping did not decrease the post-operative bleeding rate. However, the possibility that wrapping was used in more complex cases and applied with different techniques, and the fact that this was a multi-centre study, may have introduced a bias in the results.6
Omentum and FL Mimatsu et al. performed a prospective study (20 pancreatoduodenectomies, PD) in which the omentum and FL were used together to protect vessels and the pancreatogastrostomy (PG). They obtained a PF rate of 10% and no post-operative bleeding was recorded. Nor were there any complications associated with the double wrapping.8
Omentum In their prospective series of 100 PD, Maeda et al. reported dividing the greater omentum in order to create a flap that is positioned in front of the vessels (portal vein and hepatic artery) and behind the anastomosis in contact with the posterior face of the PJ and the hepaticojejunostomy without covering the front face of the PJ, covering and protecting arterial stumps such as the gastroduodenal artery stump. The authors stress the need to ensure that the stomach is not torsioned. They fix the flap only if it is deemed necessary and perform Doppler ultrasound during and after surgery
to ensure proper portal flow. In this study, the PF rate was 15% and the post-operative bleeding rate was 1%. The only patient who presented bleeding had a body mass index of 15, and the omentum was extremely thin. The authors concluded that wrapping is effective for preventing bleeding but not for diminishing PF.7 Choi et al. presented a retrospective series of 68 PD divided into two non-randomized but comparable groups. In one group, an omental flap was wrapped around the PJ to protect the anastomosis and to decrease the rate of PF, and also to protect retroperitoneal vessels. The omentum was fixed to prevent post-operative mobilization. In the second group, the omental roll was not used. The overall PF rate for the series was high (42.3%). The group of patients who underwent omental wrapping of the PJ showed a significantly lower rate of fistulas (20.7% versus 59%), less severe fistulas (grade A) and shorter hospital stay. There was no difference in post-operative bleeding rate between the two groups, although two patients without wrapping had late pseudoaneurysms.4 Kapoor et al. presented a prospective series of 77 PD, in 25 of which a double omental flap was used: one wrap to cover PJ, and the other covering the duodenojejunostomy. No complications were reported. The PF rate was similar in the wrapping and non-wrapping groups, but the fistulas were less severe in patients with wrapping. The rates of bleeding and mortality were similar in the two groups, but there was no mortality related to post-operative bleeding in the wrapping group.3 In their retrospective series of 54 PD, Kurosaki et al. used the omentum to protect vessels, placing it in the retroperitoneum and behind the PJ. The PF rate was 9.3% and there was no bleeding.12 In a prospective series of 61 PD in which PG was used in all cases, Rosso et al. compared 33 patients with a double omental flap with 28 patients without wrapping. The double flap protected regional vessels and PG anastomosis. Morbidity was 27.8% and the PF rate was 13.1%. The omental flap group presented a reduced rate of relaparotomy (10.7% versus 0%) and perianastomotic collections, but more pleural effusions.9 Matsuda et al. published a retrospective series of 229 patients, in 157 of which an omental flap was performed to protect regional vessels. The overall PF rate was 35.4% and the post-operative haemorrhage rate was 3.9% (nine patients). The rate of bleeding in the group without the flap was 8.3%, compared with 1.9% in the group with the flap.1
Falciform ligament Iannitti et al. reported using the FL to protect the PJ or pancreatic section of the PD in a retrospective series of 95 patients. These authors use FL circumferentially, if technically feasible. Otherwise, they cover only the anterior-superior face and then use aprotinin (Tissucol, Baxter Healthcare, Deerfield, IL, USA) to fix the flap to the pancreas. In the 38 DP, no PF were recorded, and in the 57 PD, the PF rate was 8.8%. In all patients with PF, dunking anastomosis was used. The author notes two biases that may affect the results: the retrospective nature of the study and the combined use of fibrin.11 Sakamoto et al. used the FL in a prospective study of 136 PD to protect the gastroduodenal artery stump. Only one patient developed post-operative bleeding, which was solved by embolization.14 © 2013 Royal Australasian College of Surgeons
Wrapping in pancreatic surgery
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Table 2 Published series about wrapping in pancreatic surgery Series
Patients
Technique
Type
Groups
Purpose
PH (%)
PF (%)
2597
PD
OG: 918 NOG: 1679
Haemorrhage/PF
Kurosaki 200412 Maeda 20057 Kapoor 20063
54 100 77
PD PD PD
FL Omentum Omentum Omentum Omentum
Mimatsu 20118 Matsuda 20121
20 229
PD PD
Omentum
68
PD
Omentum
61
PD
Omentum
95
DP (38) PD (57) PD PD DP
FL
OG: 157 NOG: 72 OG: 39 NOG: 29 OG: 33 NOG: 28 — — — — —
OG: 3.5 NOG: 3.2 1 1 OG: 0 NOG: 3.8 0 OG: 1.9 NOG: 8.3 OG: — NOG: — OG: xx NOG: xx — — 0.7 0 —
OG: 42.8 NOG: 37.3 9.3 15 OG: 16 NOG: 21 10 OG: 36.9 NOG: 31.9 OG: 20.7 NOG: 59 OG: xx NOG: xx 0 (DP) 8.8 (PD) — 28 —
Tani 2011
6
Choi 20124 Rosso 20129 Iannitti 2006
11
Sakamoto 200714 Abe 200713 Walters 201115
136 36 23
FL FL FL
— OG: 25 NOG: 52
Haemorrhage Haemorrhage Haemorrhage/PF Haemorrhage/PF Haemorrhage Haemorrhage/PF Haemorrhage/PF PF Haemorrhage Haemorrhage PF
DP, distal pancreatectomy; FL, falciform ligament; NOG, non-omental group; OG, omental group; PD, pancreatoduodenectomy; PF, pancreatic fistula; PH, post-operative haemorrhage; xx, not available.
Abe et al. used the FL in a retrospective series of 36 PD, solely as vascular protection. There were no complications related to the wrapping procedure. The PF rate was 28% (70% grade A).2 Walters et al. conducted a retrospective study of 23 consecutive patients who underwent open DP and splenectomy with closure of the pancreatic stump using a pedicled FL flap. Two patients (8.7%) developed grade C PF. There were no perioperative mortalities. They conclude that use of a pedicled FL flap for coverage of the pancreatic stump is associated with a low incidence of postoperative PF, but more investigation of this technique is warranted.
Discussion Pancreatic resection is the only therapeutic option that obtains longterm survival in pancreatic cancer.3 Depending on the location of the tumour, either PD or DP is used. PD is a complex technique, which is currently performed at specialized centres and carries a mortality of less than 5%.1,3,5–7,11,12 Its mortality has fallen dramatically because of improvements in the surgical technique and perioperative care.2–6 However, morbidity rates remain high, ranging from 30% to 65%.1–6,9,11 The three most common complications of PD are PF (5–53% of patients), postoperative bleeding (1–10%) and delayed gastric emptying (25%).1–9 DP is performed in tumours of the body and tail of the pancreas. Its mortality rate is low but its morbidity remains high, primarily associated with PF. PF is a frequent complication in DP, with rates ranging from 5% to 60%.11,13 Post-operative bleeding in DP only occurs in 2–4%.2 The huge variation in complication rates are due in part to the wide range of definitions used by different authors. The International Study Group of Pancreatic Surgery has now provided strict characterizations for these complications, which means that the results of the studies can be compared.11,16–18 PF is the most serious complication after pancreatic surgery. Its mortality rate ranges from 8% to 28%, and its direct and indirect © 2013 Royal Australasian College of Surgeons
morbidity rates are also high, as it causes intra-abdominal infection and/or bleeding of the great abdominal vessels in 16–40% of patients.1,3–5,7,10,12,14 Some risk factors for PF have been identified: soft pancreatic parenchyma, small pancreatic duct, perioperative transfusion, post-operative bleeding, heart disease and advanced age.4,7 Due to the importance of avoiding PF, and in the absence of an optimal technique, many technical variations have been tested for creating the anastomosis between the gut and pancreas in order to decrease the rate of PF in PD and DP:9 various types of pancreatojejunostomy, PG, duct-mucosa anastomosis, use of tutors, use of biological adhesives, staplers closure, duct occlusion, octreotide, external drainage and so on.3,4,11,12,14 One technique used to decrease the rate of PF and to avoid other possible complications such as post-operative bleeding is wrapping.1–14 The wrapping technique involves the use of the omentum or FL to wrap the local retroperitoneal vessel, the PJ anastomosis and the pancreatic section of DP. Wrapping was first reported in pancreatic surgery by Moriura in 1994. It has two main aims: (1) To reduce the rate of PF: placing the omentum or FL around the PJ anastomosis or DP pancreatic section can avoid the complications that PF causes;2–4,6,7,11,13 (2) To protect the surrounding organs against the autolytic effect and proteolytic activity of the pancreatic juice (rich in pancreatic trypsin and elastase) and infected fluids, especially the abdominal vessels (portal vein, hepatic artery, gastroduodenal artery stump or splenic, celiac trunk, aorta and vena cava), if an FP exists. The theoretical idea is to lower the rate of post-operative haemorrhage or pseudoaneurysms and to avoid the slipping of vascular ligatures.1–4,6,7,12,13 The omentum flap had been previously used in other fields of surgery to reinforce anastomosis or to cover tissue defects.4,7 The omentum has excellent vascularity, a high capacity to absorb fluids, adhesion formation, neovascularization, prothrombin activation, defence against infection and accelerated healing of defects.1,3,4,7,9,10,12
4
However, the wrapping of the greater omentum may present complications such as panniculitis, intestinal obstruction, necrosis of the omentum and intra-abdominal abscess.2,6,7,13,19 In some patients, the omentum cannot be used because of its excessive or insufficient size or for other reasons.2 The FL shares some of the features of the omentum. As it is smaller and shorter, it can be used to cover vascular structures but it may be too small to wrap a PJ, or even the section of the pancreas after DP.4,11 According to some authors, an adequate dissection can obtain about 10–15 cm of the FL; thus, the FL can reach any location in order to wrap peripancreatic skeletonized vessels and can be fixed to the retroperitoneum to prevent mobilization.2,11–15 Significantly, hardly any complications have been associated with its use. An FL flap is also easier to prepare than an omentum flap, and takes only 10 min.14 To summarize, the published literature on omentum and/or FL wrapping in oncologic pancreatic surgery is scarce. Retrospective and prospective studies are not randomized and often have no control group, so their level of evidence is low. They also mix different types of pancreatic surgery and various wrapping techniques, making it difficult to compare the results. Among the five papers that compare a wrapping group and a control group, only the prospective series of Choi et al. obtained a statistically significant reduction in PF in the wrapping group. Matsuda’s series presented a lower percentage of post-operative haemorrhage in the wrapping group.1,4 In the series without control groups, the results are good, but no information is provided on the results obtained when the wrapping technique was not used. It seems that the use of the omentum and/or FL may slightly decrease the rate of post-operative bleeding and PF, and when PF occurs, it may be less severe.7,8,11–15
Conclusion On the basis of the literature available at present, we cannot recommend the use of wrapping with omentum and/or FL in pancreatic surgery. Prospective randomized studies applying a systematic wrapping technique are needed in order to establish whether its use should be generalized.
References 1. Matsuda H, Sadamori H, Umeda Y et al. Preventive effect of omental flap in pancreatoduodenectomy against postoperative pseudoaneurysm formation. Hepatogastroenterology 2012; 59: 578–83. 2. Abe N, Sugiyama M, Suzuki Y et al. Falciform ligament in pancreatoduodenectomy for protection of skeletonized and divided vessels. J. Hepatobiliary Pancreat. Surg. 2009; 16: 184–8. 3. Kapoor VK, Sharma A, Behari A, Singh RK. Omental flaps in pancreaticoduodenectomy. JOP 2006; 7: 608–15.
Ramia et al.
4. Choi SB, Lee JS, Kim WB, Song TJ, Suh SO, Choi SY Efficacy of the omental roll-up technique in pancreatojejunostomy as a strategy to prevent pancreatic fistula after pancreaticoduodenectomy. Arch. Surg. 2012; 147: 145–50. 5. Seyama Y, Kubora K, Kobayashi T, Hirata Y, Itoh A, Makuuchi M. Two-staged pancreatoduodenectomy with external drainage of pancreatic juice and omental graft technique. J. Am. Coll. Surg. 1998; 187: 103–5. 6. Tani M, Kawai M, Hirono S et al. Use of omentum or falciform ligament does not decrease complications after pancreaticoduodenectomy: nationwide survey of the Japanese Society of Pancreatic Surgery. Surgery 2012; 151: 183–91. 7. Maeda A, Ebata T, Kanemoto H et al. Omental flap in pancreatoduonectomy for protection of splanchnic vessels. World J. Surg. 2005; 29: 1122–6. 8. Mimatsu K, Oida T, Kano H et al. Protection of major vessels and pancreaticogastrostomy using the falciform ligament and greater omentum for preventing pancreatic fistula in soft pancreatic texture after pancreaticoduodenectomy. Hepatogastroenterology 2011; 58: 1782–6. 9. Rosso E, Lopez P, Roedlisch MN, Narita M, Oussoultzoglou E, Bachellier P. Double omental flap reduced perianastomotic collections and relaparotomy rates after pancreaticoduodenectomy with pancreaticogastrostomy. World J. Surg. 2012; 36: 1672–8. 10. Moriura S, Ikeda S, Ikezawa T, Naiki K. The inclusion of an omental flap in pancreatoduodenectomy. Surg. Today 1994; 24: 940–1. 11. Iannitti DA, Coburn NG, Somberg J, Ryder BA, Monchik J, Cioffi WG. Use of the round ligament of the liver to decrease pancreatic fistulas: a novel technique. J. Am. Coll. Surg. 2006; 203: 857–64. 12. Kurosaki I, Hatakeyama K. Omental wrapping of skeletonized major vessels after pancreaticoduodenectomy. Int. Surg. 2004; 89: 90–4. 13. Abe N, Sugiyama M, Yanagida O, Masaki T, Mori T, Atomi Y. Wrapping of skeletonized and divided vessels using the falciform ligament in distal pancreatectomy. Am. J. Surg. 2007; 194: 94–7. 14. Sakamoto Y, Shimada K, Esaki M, Kajiwara T, Sano T, Kosuge T. Wrapping the stump of the gastroduodenal artery using the falciform ligament during pancreatoduodenectomy. J. Am. Coll. Surg. 2007; 204: 334–6. 15. Walters DM, Stokes JB, Adams RB, Bauer TW. Use of a falciform ligament pedicle flap to decrease pancreatic fistula after distal pancreatectomy. Pancreas 2011; 40: 595–9. 16. Bassi C, Dervenis C, Butturini G et al., International Study Group on Pancreatic Fistula Definition. Postoperative pancreatic fistula: an International Study Group (ISGPF) definition. Surgery 2005; 138: 8–13. 17. Wente MN, Veit JA, Bassi C et al. Postpancreatectomy hemorrhage (PPH) an International Study Group of Pancreatic Surgery (ISGPS) definition. Surgery 2007; 142: 20–5. 18. Wente MN, Bassi C, Dervenis C et al. Delayed gastric empting (DGE) after pancreatic surgery: a suggested definition by the International Study Group of Pancreatic Surgery (ISGPS). Surgery 2007; 142: 761–8. 19. Liebermann D. The greater omentum. Anatomy, embryology and surgical applications. Surg. Clin. North Am. 2000; 80: 275–93.
© 2013 Royal Australasian College of Surgeons
Wrapping in pancreatic surgery: a systematic review Jose M. Ramia, Roberto de la Plaza, Farah Adel, Carmen Ramiro, Vladimir Arteaga and Jorge Garcia-Parreño HPB Surgical Service, Department of Surgery, University Hospital of Guadalajara, Guadalajara, Spain
Key words falciform, omental, omentum, pancreas, pancreatoduodenectomy, review, surgery, wrapping. Correspondence Mr Jose M. Ramia, HPB Surgical Service, Department of Surgery, University Hospital of Guadalajara, C/General Moscardó 26, 5-1, Madrid 28020, Spain. Email: [email protected] J. M. Ramia MD, PhD, FACS; R. de la Plaza MD; F. Adel MD; C. Ramiro MD; V. Arteaga MD; J. Garcia-Parreño MD, PhD. Accepted for publication 14 November 2013. doi: 10.1111/ans.12491
Abstract Background: Wrapping in pancreatic surgery involves the use of the omentum or falciform ligament (FL) to wrap the local retroperitoneal vessels, the pancreatojejunal anastomosis or the pancreatic section of distal pancreatectomy. However, there is no clear evidence that wrapping in fact provides benefits. We have performed a systematic review of the literature about this topic. Methods: We conducted a literature search in the PubMed/MEDLINE database (1966–2012) for any language using various combinations of the following terms: wrapping, omental, omentum, pancreas, pancreatoduodenectomy and falciform ligament. Results: We selected 12 articles. Among five series that included a control group, only one obtained a statistically significant reduction in pancreatic fistula (PF) in the wrapping group and other series showed a lower percentage of post-operative haemorrhage in the wrapping group. In the seven series without control groups, a slight decrease in the rate of post-operative bleeding and PF was observed. Conclusions: On the basis of the literature available at present, we cannot recommend the use of wrapping with omentum and/or FL in pancreatic surgery. Prospective randomized studies applying a systematic wrapping technique are needed in order to establish whether its use should be generalized.
Introduction
Material and methods
Pancreatic fistula (PF) and post-operative bleeding are the most serious complications after pancreatic surgery.1–9 Multiple technical modifications have been used in attempts to reduce the incidence of these complications. One of these practices is wrapping, using the omentum or falciform ligament (FL). First described by Moriura in 1994, wrapping in pancreatic surgery involves the use of the omentum or FL to wrap the local retroperitoneal vessels, the pancreatojejunal (PJ) anastomosis or the pancreatic section of distal pancreatectomy (DP). Although popular in Asia, the technique is not in frequent use in Europe or the US.1,2,5,6,9–11 It has two purposes: firstly, to reduce the rate of postoperative haemorrhage and pseudoaneurysms, avoiding the slipping of vascular ligatures due to the action of pancreatic juice,1–4,6,7,12,13 and, secondly, to decrease the rate of PF around the PJ anastomosis or in the DP section, thereby preventing the associated complications.2–4,6,7,11,13 At present, however, there is no clear evidence that wrapping in fact provides benefits. To assess the true value of the technique, we decided to perform a meta-analysis and systematic review of the literature.
We conducted a literature search in the PubMed/MEDLINE database (1966–2012) (National Library of Medicine, Bethesda, MD, USA) for any language using various combinations of the following terms: wrapping, omental, omentum, pancreas, pancreatoduodenectomy and falciform ligament (Table 1). After reading the abstracts, we concluded that only 15 articles were relevant to our research aims. Because of the small number, we checked the references of these articles but did not find more studies on the subject. Among these 15 articles, there were no randomized control trials (Table 2). Two focused on the surgical technique;5,10 two more were written by the same surgical teams,2,13 of which we selected the one that included more patients. Finally, we selected 12 articles,1–4,6–9,11,12,14,15 which form the basis of our research. Five articles compared groups with and without the use of omentum or FL as wrapping,1,3,4,6,9 and the other seven described series of patients in whom some kind of wrapping was performed.2,7,8,11,12,14,15 Seven studies were retrospective1,2,4,6,11,12,15 and five were prospective.3,7–9
© 2013 Royal Australasian College of Surgeons
ANZ J Surg •• (2013) ••–••
2
Ramia et al.
Table 1 Key words search Words
Wrapping and omental Wrapping and omentum Wrapping and pancreas Wrapping and pancreatoduodenectomy Wrapping and falciform Falciform and pancreas Falciform and pancreatoduodenectomy Total
Records screened
Full-text articles assessed for eligibility
Studies included
176 123 36 11
7 5 3 7
5 5 2 5
5 16 4
4 5 4
4 5 4
371
35/19†
30/15†
†Excluding repeat articles.
Results After abandoning our initial idea of conducting a meta-analysis due to the absence of randomized trials that could be compared, we conducted a systematic literature review. We grouped the articles by type of wrapping: omentum, FL or both.
Omentum and/or FL Tani et al. conducted a multi-centre retrospective study of 2597 patients who underwent pancreatic surgery. Wrapping with omentum and/or FL was performed in 918 patients. Wrapping patients had a longer operative time, a higher PF rate, more severe fistulas (grades B and C) and more wound infection. Interestingly, the amylase level in the drainage was lower in the group with wrapping. The results obtained with FL were better than those obtained with omentum. The location of the wrapping (vessel protection or peri-anastomotic) did not change the complication rate, which was higher in the group with wrapping in all cases. Wrapping did not decrease the post-operative bleeding rate. However, the possibility that wrapping was used in more complex cases and applied with different techniques, and the fact that this was a multi-centre study, may have introduced a bias in the results.6
Omentum and FL Mimatsu et al. performed a prospective study (20 pancreatoduodenectomies, PD) in which the omentum and FL were used together to protect vessels and the pancreatogastrostomy (PG). They obtained a PF rate of 10% and no post-operative bleeding was recorded. Nor were there any complications associated with the double wrapping.8
Omentum In their prospective series of 100 PD, Maeda et al. reported dividing the greater omentum in order to create a flap that is positioned in front of the vessels (portal vein and hepatic artery) and behind the anastomosis in contact with the posterior face of the PJ and the hepaticojejunostomy without covering the front face of the PJ, covering and protecting arterial stumps such as the gastroduodenal artery stump. The authors stress the need to ensure that the stomach is not torsioned. They fix the flap only if it is deemed necessary and perform Doppler ultrasound during and after surgery
to ensure proper portal flow. In this study, the PF rate was 15% and the post-operative bleeding rate was 1%. The only patient who presented bleeding had a body mass index of 15, and the omentum was extremely thin. The authors concluded that wrapping is effective for preventing bleeding but not for diminishing PF.7 Choi et al. presented a retrospective series of 68 PD divided into two non-randomized but comparable groups. In one group, an omental flap was wrapped around the PJ to protect the anastomosis and to decrease the rate of PF, and also to protect retroperitoneal vessels. The omentum was fixed to prevent post-operative mobilization. In the second group, the omental roll was not used. The overall PF rate for the series was high (42.3%). The group of patients who underwent omental wrapping of the PJ showed a significantly lower rate of fistulas (20.7% versus 59%), less severe fistulas (grade A) and shorter hospital stay. There was no difference in post-operative bleeding rate between the two groups, although two patients without wrapping had late pseudoaneurysms.4 Kapoor et al. presented a prospective series of 77 PD, in 25 of which a double omental flap was used: one wrap to cover PJ, and the other covering the duodenojejunostomy. No complications were reported. The PF rate was similar in the wrapping and non-wrapping groups, but the fistulas were less severe in patients with wrapping. The rates of bleeding and mortality were similar in the two groups, but there was no mortality related to post-operative bleeding in the wrapping group.3 In their retrospective series of 54 PD, Kurosaki et al. used the omentum to protect vessels, placing it in the retroperitoneum and behind the PJ. The PF rate was 9.3% and there was no bleeding.12 In a prospective series of 61 PD in which PG was used in all cases, Rosso et al. compared 33 patients with a double omental flap with 28 patients without wrapping. The double flap protected regional vessels and PG anastomosis. Morbidity was 27.8% and the PF rate was 13.1%. The omental flap group presented a reduced rate of relaparotomy (10.7% versus 0%) and perianastomotic collections, but more pleural effusions.9 Matsuda et al. published a retrospective series of 229 patients, in 157 of which an omental flap was performed to protect regional vessels. The overall PF rate was 35.4% and the post-operative haemorrhage rate was 3.9% (nine patients). The rate of bleeding in the group without the flap was 8.3%, compared with 1.9% in the group with the flap.1
Falciform ligament Iannitti et al. reported using the FL to protect the PJ or pancreatic section of the PD in a retrospective series of 95 patients. These authors use FL circumferentially, if technically feasible. Otherwise, they cover only the anterior-superior face and then use aprotinin (Tissucol, Baxter Healthcare, Deerfield, IL, USA) to fix the flap to the pancreas. In the 38 DP, no PF were recorded, and in the 57 PD, the PF rate was 8.8%. In all patients with PF, dunking anastomosis was used. The author notes two biases that may affect the results: the retrospective nature of the study and the combined use of fibrin.11 Sakamoto et al. used the FL in a prospective study of 136 PD to protect the gastroduodenal artery stump. Only one patient developed post-operative bleeding, which was solved by embolization.14 © 2013 Royal Australasian College of Surgeons
Wrapping in pancreatic surgery
3
Table 2 Published series about wrapping in pancreatic surgery Series
Patients
Technique
Type
Groups
Purpose
PH (%)
PF (%)
2597
PD
OG: 918 NOG: 1679
Haemorrhage/PF
Kurosaki 200412 Maeda 20057 Kapoor 20063
54 100 77
PD PD PD
FL Omentum Omentum Omentum Omentum
Mimatsu 20118 Matsuda 20121
20 229
PD PD
Omentum
68
PD
Omentum
61
PD
Omentum
95
DP (38) PD (57) PD PD DP
FL
OG: 157 NOG: 72 OG: 39 NOG: 29 OG: 33 NOG: 28 — — — — —
OG: 3.5 NOG: 3.2 1 1 OG: 0 NOG: 3.8 0 OG: 1.9 NOG: 8.3 OG: — NOG: — OG: xx NOG: xx — — 0.7 0 —
OG: 42.8 NOG: 37.3 9.3 15 OG: 16 NOG: 21 10 OG: 36.9 NOG: 31.9 OG: 20.7 NOG: 59 OG: xx NOG: xx 0 (DP) 8.8 (PD) — 28 —
Tani 2011
6
Choi 20124 Rosso 20129 Iannitti 2006
11
Sakamoto 200714 Abe 200713 Walters 201115
136 36 23
FL FL FL
— OG: 25 NOG: 52
Haemorrhage Haemorrhage Haemorrhage/PF Haemorrhage/PF Haemorrhage Haemorrhage/PF Haemorrhage/PF PF Haemorrhage Haemorrhage PF
DP, distal pancreatectomy; FL, falciform ligament; NOG, non-omental group; OG, omental group; PD, pancreatoduodenectomy; PF, pancreatic fistula; PH, post-operative haemorrhage; xx, not available.
Abe et al. used the FL in a retrospective series of 36 PD, solely as vascular protection. There were no complications related to the wrapping procedure. The PF rate was 28% (70% grade A).2 Walters et al. conducted a retrospective study of 23 consecutive patients who underwent open DP and splenectomy with closure of the pancreatic stump using a pedicled FL flap. Two patients (8.7%) developed grade C PF. There were no perioperative mortalities. They conclude that use of a pedicled FL flap for coverage of the pancreatic stump is associated with a low incidence of postoperative PF, but more investigation of this technique is warranted.
Discussion Pancreatic resection is the only therapeutic option that obtains longterm survival in pancreatic cancer.3 Depending on the location of the tumour, either PD or DP is used. PD is a complex technique, which is currently performed at specialized centres and carries a mortality of less than 5%.1,3,5–7,11,12 Its mortality has fallen dramatically because of improvements in the surgical technique and perioperative care.2–6 However, morbidity rates remain high, ranging from 30% to 65%.1–6,9,11 The three most common complications of PD are PF (5–53% of patients), postoperative bleeding (1–10%) and delayed gastric emptying (25%).1–9 DP is performed in tumours of the body and tail of the pancreas. Its mortality rate is low but its morbidity remains high, primarily associated with PF. PF is a frequent complication in DP, with rates ranging from 5% to 60%.11,13 Post-operative bleeding in DP only occurs in 2–4%.2 The huge variation in complication rates are due in part to the wide range of definitions used by different authors. The International Study Group of Pancreatic Surgery has now provided strict characterizations for these complications, which means that the results of the studies can be compared.11,16–18 PF is the most serious complication after pancreatic surgery. Its mortality rate ranges from 8% to 28%, and its direct and indirect © 2013 Royal Australasian College of Surgeons
morbidity rates are also high, as it causes intra-abdominal infection and/or bleeding of the great abdominal vessels in 16–40% of patients.1,3–5,7,10,12,14 Some risk factors for PF have been identified: soft pancreatic parenchyma, small pancreatic duct, perioperative transfusion, post-operative bleeding, heart disease and advanced age.4,7 Due to the importance of avoiding PF, and in the absence of an optimal technique, many technical variations have been tested for creating the anastomosis between the gut and pancreas in order to decrease the rate of PF in PD and DP:9 various types of pancreatojejunostomy, PG, duct-mucosa anastomosis, use of tutors, use of biological adhesives, staplers closure, duct occlusion, octreotide, external drainage and so on.3,4,11,12,14 One technique used to decrease the rate of PF and to avoid other possible complications such as post-operative bleeding is wrapping.1–14 The wrapping technique involves the use of the omentum or FL to wrap the local retroperitoneal vessel, the PJ anastomosis and the pancreatic section of DP. Wrapping was first reported in pancreatic surgery by Moriura in 1994. It has two main aims: (1) To reduce the rate of PF: placing the omentum or FL around the PJ anastomosis or DP pancreatic section can avoid the complications that PF causes;2–4,6,7,11,13 (2) To protect the surrounding organs against the autolytic effect and proteolytic activity of the pancreatic juice (rich in pancreatic trypsin and elastase) and infected fluids, especially the abdominal vessels (portal vein, hepatic artery, gastroduodenal artery stump or splenic, celiac trunk, aorta and vena cava), if an FP exists. The theoretical idea is to lower the rate of post-operative haemorrhage or pseudoaneurysms and to avoid the slipping of vascular ligatures.1–4,6,7,12,13 The omentum flap had been previously used in other fields of surgery to reinforce anastomosis or to cover tissue defects.4,7 The omentum has excellent vascularity, a high capacity to absorb fluids, adhesion formation, neovascularization, prothrombin activation, defence against infection and accelerated healing of defects.1,3,4,7,9,10,12
4
However, the wrapping of the greater omentum may present complications such as panniculitis, intestinal obstruction, necrosis of the omentum and intra-abdominal abscess.2,6,7,13,19 In some patients, the omentum cannot be used because of its excessive or insufficient size or for other reasons.2 The FL shares some of the features of the omentum. As it is smaller and shorter, it can be used to cover vascular structures but it may be too small to wrap a PJ, or even the section of the pancreas after DP.4,11 According to some authors, an adequate dissection can obtain about 10–15 cm of the FL; thus, the FL can reach any location in order to wrap peripancreatic skeletonized vessels and can be fixed to the retroperitoneum to prevent mobilization.2,11–15 Significantly, hardly any complications have been associated with its use. An FL flap is also easier to prepare than an omentum flap, and takes only 10 min.14 To summarize, the published literature on omentum and/or FL wrapping in oncologic pancreatic surgery is scarce. Retrospective and prospective studies are not randomized and often have no control group, so their level of evidence is low. They also mix different types of pancreatic surgery and various wrapping techniques, making it difficult to compare the results. Among the five papers that compare a wrapping group and a control group, only the prospective series of Choi et al. obtained a statistically significant reduction in PF in the wrapping group. Matsuda’s series presented a lower percentage of post-operative haemorrhage in the wrapping group.1,4 In the series without control groups, the results are good, but no information is provided on the results obtained when the wrapping technique was not used. It seems that the use of the omentum and/or FL may slightly decrease the rate of post-operative bleeding and PF, and when PF occurs, it may be less severe.7,8,11–15
Conclusion On the basis of the literature available at present, we cannot recommend the use of wrapping with omentum and/or FL in pancreatic surgery. Prospective randomized studies applying a systematic wrapping technique are needed in order to establish whether its use should be generalized.
References 1. Matsuda H, Sadamori H, Umeda Y et al. Preventive effect of omental flap in pancreatoduodenectomy against postoperative pseudoaneurysm formation. Hepatogastroenterology 2012; 59: 578–83. 2. Abe N, Sugiyama M, Suzuki Y et al. Falciform ligament in pancreatoduodenectomy for protection of skeletonized and divided vessels. J. Hepatobiliary Pancreat. Surg. 2009; 16: 184–8. 3. Kapoor VK, Sharma A, Behari A, Singh RK. Omental flaps in pancreaticoduodenectomy. JOP 2006; 7: 608–15.
Ramia et al.
4. Choi SB, Lee JS, Kim WB, Song TJ, Suh SO, Choi SY Efficacy of the omental roll-up technique in pancreatojejunostomy as a strategy to prevent pancreatic fistula after pancreaticoduodenectomy. Arch. Surg. 2012; 147: 145–50. 5. Seyama Y, Kubora K, Kobayashi T, Hirata Y, Itoh A, Makuuchi M. Two-staged pancreatoduodenectomy with external drainage of pancreatic juice and omental graft technique. J. Am. Coll. Surg. 1998; 187: 103–5. 6. Tani M, Kawai M, Hirono S et al. Use of omentum or falciform ligament does not decrease complications after pancreaticoduodenectomy: nationwide survey of the Japanese Society of Pancreatic Surgery. Surgery 2012; 151: 183–91. 7. Maeda A, Ebata T, Kanemoto H et al. Omental flap in pancreatoduonectomy for protection of splanchnic vessels. World J. Surg. 2005; 29: 1122–6. 8. Mimatsu K, Oida T, Kano H et al. Protection of major vessels and pancreaticogastrostomy using the falciform ligament and greater omentum for preventing pancreatic fistula in soft pancreatic texture after pancreaticoduodenectomy. Hepatogastroenterology 2011; 58: 1782–6. 9. Rosso E, Lopez P, Roedlisch MN, Narita M, Oussoultzoglou E, Bachellier P. Double omental flap reduced perianastomotic collections and relaparotomy rates after pancreaticoduodenectomy with pancreaticogastrostomy. World J. Surg. 2012; 36: 1672–8. 10. Moriura S, Ikeda S, Ikezawa T, Naiki K. The inclusion of an omental flap in pancreatoduodenectomy. Surg. Today 1994; 24: 940–1. 11. Iannitti DA, Coburn NG, Somberg J, Ryder BA, Monchik J, Cioffi WG. Use of the round ligament of the liver to decrease pancreatic fistulas: a novel technique. J. Am. Coll. Surg. 2006; 203: 857–64. 12. Kurosaki I, Hatakeyama K. Omental wrapping of skeletonized major vessels after pancreaticoduodenectomy. Int. Surg. 2004; 89: 90–4. 13. Abe N, Sugiyama M, Yanagida O, Masaki T, Mori T, Atomi Y. Wrapping of skeletonized and divided vessels using the falciform ligament in distal pancreatectomy. Am. J. Surg. 2007; 194: 94–7. 14. Sakamoto Y, Shimada K, Esaki M, Kajiwara T, Sano T, Kosuge T. Wrapping the stump of the gastroduodenal artery using the falciform ligament during pancreatoduodenectomy. J. Am. Coll. Surg. 2007; 204: 334–6. 15. Walters DM, Stokes JB, Adams RB, Bauer TW. Use of a falciform ligament pedicle flap to decrease pancreatic fistula after distal pancreatectomy. Pancreas 2011; 40: 595–9. 16. Bassi C, Dervenis C, Butturini G et al., International Study Group on Pancreatic Fistula Definition. Postoperative pancreatic fistula: an International Study Group (ISGPF) definition. Surgery 2005; 138: 8–13. 17. Wente MN, Veit JA, Bassi C et al. Postpancreatectomy hemorrhage (PPH) an International Study Group of Pancreatic Surgery (ISGPS) definition. Surgery 2007; 142: 20–5. 18. Wente MN, Bassi C, Dervenis C et al. Delayed gastric empting (DGE) after pancreatic surgery: a suggested definition by the International Study Group of Pancreatic Surgery (ISGPS). Surgery 2007; 142: 761–8. 19. Liebermann D. The greater omentum. Anatomy, embryology and surgical applications. Surg. Clin. North Am. 2000; 80: 275–93.
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