Objectives: Graft duodenal perforation is a serious complication in pancreas transplantation. The aim of this study was to evaluate whether using a reinforced linear stapler during bench surgery in pancreas transplant affects the risk of graft duodenal perforation.
Materials and Methods: This retrospective study included 47 patients who underwent pancreas transplant at our institution from 2011 to 2020. A reinforced stapler with polyglycolic acid felt was used to dissect the graft duodenum during bench surgery
in 16 of the 47 patients (reinforced group). A conventional linear stapler was used in the remaining 31 patients (conventional group). Demographic, perioperative, and postoperative parameters were compared between the reinforced group and the conventional group.
Results: Graft duodenal perforation occurred in 6 patients (19.4%) in the conventional group and in none of the patients in the reinforced group. Logistic regression analysis revealed no significant as-sociations between donor- or recipient-related factors and graft duodenal perforation. Among operative factors, use of a reinforced stapler was the only factor significantly associated with the risk of graft duodenal perforation (odds ratio = 0.12).
Conclusions: The use of a reinforced stapler during dissection of the duodenum in bench surgery for pancreas transplant was associated with a lower risk of graft duodenal perforation than use of a conventional stapler.
Key words : Duodenum, Graft survival, Type 1 diabetes
Pancreas transplant is an effective treatment that allows insulin independence in patients with type 1 diabetes.1 However, the procedure is also highly invasive and has more complications than other solid-organ transplant procedures.2 The main complications of pancreas transplant are bleeding, thrombosis, graft duodenal perforation, graft pancreatitis, and perigraft abscess.3-6 Of these, graft duodenal perforation is a serious complication requiring prolonged drainage, reoperation, and graftectomy. The incidence of graft duodenal perforation has been reported to range from about 5% to 8%.7 Graft duodenal perforation is an important issue that must be overcome whenever enteric exocrine drainage is chosen. Ischemia-reperfusion injury, rejection, and, especially in the late phase, cytomegalovirus infection are reported causes of graft duodenal perforation.8-11 Ischemia of the graft duodenal stump and increased internal pressure at the anastomosis site may be additional factors. The occurrence of graft duodenal perforation is directly related to graft prognosis because this complication may require reoperation or graftectomy.
There are reports of Roux-en-Y enteric drainage12,13 and the use of a unique “button technique” to prevent this complication.14 Walter and colleagues reported that duodenoduodenostomy was associated with less anastomotic insufficiency than duodenojejunostomy.15 However, all of these operations require major changes in procedures and special techniques. Therefore, we investigated a simpler method to reduce the risk of duodenal perforation. Because most reported perforation sites are in the duodenal stump, we focused on the stump treatment method.16 Previously, we stapled the graft duodenum with a DST Series GIA stapler (Covidien) or an EES linear cutter (Ethicon). In some cases, the staple line was reinforced with additional seromuscular sutures, but this did not completely prevent graft duodenal perforation. Therefore, as a new technique, we began to staple the graft duodenum with a reinforced stapler (Endo GIA Reinforced Reload with Tri-Staple Technology; Covidien). This automatic stapling device has preattached suture reinforcement felt (Neoveil; Gunze) made of polyglycolic acid (PGA). The improved pressure resistance is expected to reduce leakage by increasing intratissue pressure and contributing to improved hemostasis.17,18 Use of the reinforced stapler has been reported in sleeve gastrectomy, colorectal surgery, distal pancreatectomy, and pulmonary wedge resection, but there are so far no reports of its use in pancreas transplant.17,19-21 We examined the effect of use of the reinforced stapler in preventing graft duodenal perforation after pancreas transplant.
Materials and Methods
Ethical approval and informed consent
This study was performed in accordance with the guidelines of the Declaration of Helsinki and was approved by the Kyushu University Institutional Review Board for Clinical Research (approval number: 30-531). Informed consent was obtained in the form of an opt-out option on the hospital Web site.
All consecutive pancreas transplants performed at Kyushu University Hospital (Fukuoka, Japan) from April 2011 through September 2020 were included in this study. During the study period, 56 pancreas transplant procedures were performed. Of these, 47 patients were included in this study. All procedures included enteric drainage, and graft duodenums and recipient ileums were anastomosed laterally with side-to-side anastomosis. The 9 excluded patients included 3 living pancreas transplant recipients, 2 patients with enteric drainage with graft duodenal patch, 2 patients with Roux-en-Y enteric drainage, 1 patient with bladder drainage, and 1 patient with left-sided transplant. Among the 47 included patients, there were 36 simultaneous kidney and pancreas transplants, 8 pancreas after kidney transplants, and 3 pancreas transplants alone. The reinforced stapler was used in 16 of the 47 cases.
The following clinical data were retrospectively collected from the medical records of Kyushu University Hospital: recipient age, recipient sex, recipient body mass index, waiting period for pancreas transplant, year of transplant, duration of type 1 diabetes mellitus, duration of dialysis, operation type, donor age, donor sex, donor body mass index, hemoglobin A1c level, cause of death, hemodynamic stability, episodes of cardiopulmonary arrest, total operation time, blood loss, total ischemic time, arterial reconstruction, gastroduodenal artery (GDA) reconstruction, complications, and duration of hospital stay.
In all cases, pancreas and kidneys were procured en bloc. During procurement of pancreas and kidneys, only gross observation of the organs was performed during warm dissection; most of the manipulation was performed during cold dissection after cross-clamping. Core cooling was achieved with University of Wisconsin cold storage solution, and surface cooling was achieved with slush ice. In most cases, the liver was procured at the same time, and the GDA and common hepatic artery were often determined to be the arterial dissection lines. The portal vein was transected to a level about 5 mm from the upper border of the pancreas, and the inferior vena cava was separated slightly cranial to the renal vein. The transverse mesocolon was separated.
The proximal side of the intestine was transected at the gastric antrum with the nonreinforced stapler (Endo GIA Reloads with Tri-Staple 60-mm purple); the distal side of the intestine was transected 20 cm from the ligament of Treitz with the nonreinforced stapler (Endo GIA Reloads with Tri-Staple 60-mm camel). The transverse mesocolon and the small intestinal mesentery were separated, and the spleen was mobilized from the retroperitoneum. The Kocher maneuver was then performed. The bilateral ureters were transected. The pancreas, kidneys, spleen, and duodenum were lifted en bloc and dissected in the layer between the vertebral body and the aorta. En bloc procurement was completed. The procured organs were stored in University of Wisconsin cold storage solution.
Surgical procedure for bench surgery using the reinforced stapler
The proximal side of the duodenum was transected with the reinforced stapler (Endo GIA Reinforced Reload with Tri-Staple 60-mm purple) just beyond the pylorus (Figure 1). The distal side was transected with the same device at the third portion of the duodenum (Figure 2). The length of the duodenum was determined to be approximately 10 cm, and no seromuscular sutures were added to either staple line (Figure 3). The GDA and common hepatic artery were reconstructed by interposition reconstruction with an I graft using the donor iliac artery or by end-to-end anastomosis. If transected at the root of the celiac artery, the superior mesenteric artery and splenic artery were reconstructed with a Y graft using the donor iliac artery.
Surgical procedure for recipient
The pancreas graft was placed in the right retroperitoneal space, the portal vein was anastomosed to the right external iliac vein, and the Carrel patch was anastomosed to the right external iliac artery. Methylprednisolone sodium succinate (250-500 mg) was injected intravenously after venous anastomosis to prevent ischemia-reperfusion injury. A 20-cm fenestration was made in the peritoneum, and the graft duodenum and recipient ileum were anastomosed laterally about 40 cm from the terminal ileum with side-to-side anastomosis with the nonreinforced stapler (Endo GIA Reloads with Tri-Staple 60-mm purple). The common channel was closed with 4/0 PDS II continuous sutures (Ethicon).
Continuous data were analyzed with the Mann-Whitney U test. Categorical data were analyzed with the chi-square test or the Fisher exact test, as appropriate. Kaplan-Meier curves were constructed to examine graft survival, and differences between groups were determined by the log-rank test. Independent factors associated with the occurrence of duodenal perforation were selected by using univariate logistic regression. If there were zero cells, each cell was corrected by adding 1/2 (Haldane-Anscombe 1/2 correction). Values of P < .05 were considered to indicate statistical significance, and all statistical analyses were performed with JMP 15.0.0 (SAS Institute) and EZR (Easy R) version 1.4122 (The R Foundation for Statistical Computing).
Among the 47 pancreas transplants included in this study, there were 16 cases in the reinforced group, in which the graft duodenum was transected with the reinforced stapler, and 31 cases in the conventional group, in which the graft was transected with the nonreinforced stapler. There was a significantly higher proportion of female patients and a significantly shorter waiting period in the reinforced group compared with the conventional group. There was a significant difference in year of transplant between the 2 groups, with all cases in the reinforced group occurring from 2016 to 2020. There were no significant differences in other factors between the 2 groups (Table 1).
Analyses of perioperative factors and postoperative course
Data on perioperative factors and postoperative course are shown in Table 2. There were no significant differences in operation time or blood loss between the 2 groups. The proportion of patients with preserved GDA flow was significantly higher in the conventional group. The proportion of patients with GDA reconstruction was also significantly higher in the conventional group. The incidence of graft duodenal perforation was higher in the conventional group (6 cases) than in the reinforced group (0 cases). The mean time to onset of graft duodenal perforation was 19.2 days (range, 8-55 days). In 5 of these 6 cases, the perforation site was at the duodenal stump, according to the results of contrast examination; in the sixth case, the site of perforation was difficult to identify. Three patients recovered with only drainage treatment, with 1 who had conversion to bladder drainage and 2 who underwent graftectomy. There were no significant between-group differences in other complications, including bleeding, perigraft abscess, and partial thrombosis. Kaplan-Meier survival analysis showed 1-year cumulative graft survival rates in the reinforced group and conventional group of 100% and 83.9% (P = .13), respectively (Figure 4).
Analyses of risk factors involved in pancreas graft duodenal perforation
Logistic regression analysis of risk factors for graft duodenal perforation showed no significant donor or recipient factors. Among operative factors, use of the reinforced stapler was the only significant factor associated with a lower risk of graft duodenal perforation, with an odds ratio of 0.12 (Table 3).
Graft duodenal perforation after pancreas transplant is a serious complication and is often difficult to treat. Conservative treatment with drainage may be successful; however, peritonitis may sometimes develop and graftectomy may be required. In our case series, 3 of the 6 graft duodenal perforations were successfully treated with drainage but required a prolonged treatment period of 2 to 3 months. One of the remaining cases was converted to bladder drainage and 2 to graftectomy. Although it did not address pancreas transplant, a study by Orsenigo and colleagues found that the absence of manual reinforcement over the duodenal stump in gastric surgery was an independent risk factor for postoperative duodenal stump fistula formation.23 We have added seromuscular sutures to the graft duodenal stump, but even this technique does not completely prevent graft duodenal perforation. Therefore, we decided to staple the graft duodenal stump with the Endo GIA Reinforced Reload with Tri-Staple with PGA attached to the fork, a product that was launched in 2014.
The reinforced material in the stapler is made of a synthetic web of fibers composed of PGA. Generally, this material is degraded by hydrolysis after 6 months, without an antigenic response.24 This reinforced stapler has been used in various surgical fields, and its efficacy has been reported. In distal pancreatectomy, use of the reinforced stapler instead of an ultrasonic dissector reduced the incidence of postoperative pancreatic fistula.20 In pulmonary wedge resection, the reinforced stapler reduced the rate of postoperative air leakage compared with nonreinforced resection.21 With the increase in laparoscopic surgery,25 several reports have shown the efficacy of the reinforced stapler in laparoscopic surgery. Nagahisa and colleagues reported that the reinforced stapler significantly reduced the rate of delta anastomotic bleeding in distal gastrectomy.18 Naito and colleagues reported that the reinforced stapler was safe and effective for low anterior large bowel resections in colorectal surgery.19 Our results also showed that use of this reinforced stapler significantly reduced the incidence of graft duodenal perforation. We used the reinforced stapler only for closure of both ends of the graft duodenum. Side-to-side anastomosis between the graft duodenum and the recipient ileum was performed with a nonreinforced stapler. In a report on sutureless functional end-to-end anastomosis using a reinforced stapler, no complications were observed.26 The reinforced stapler may also be useful for side-to-side anastomosis of duodenoileostomy and common channel closure to prevent both perforation and bleeding.
Interestingly, patients with preserved GDA blood flow had a higher incidence of graft duodenal perforation than other patients, although this difference was not statistically significant. In theory, preserved GDA blood flow should help maintain blood flow in the pancreas head and graft duodenum, leading to a better graft outcome.27 Nghiem and colleagues reported that 14.2% of pancreas grafts did not have adequate blood supply to the pancreas head and the duodenum on angiography,28 indicating that the GDA may require reconstruction. However, the GDA can be sacrificed in many cases because of the presence of the pancreatic arcade. For example, when Y-graft reconstruction is required, the GDA is usually sacrificed.29 Thus, the need for GDA reconstruction is controversial. Although this study was not designed to assess the need for GDA reconstruction, our findings suggest that not performing GDA reconstruction may not affect graft duodenal perforation. A more important factor affecting the outcome was the proper manipulation of the graft duodenal stump.
There are some limitations to this study. First, the incidence rate of graft duodenal perforation in our institution with the use of a conventional nonreinforced stapler was 19.4%, which was higher than shown in previous reports. However, since the introduction of the reinforced stapler, no cases of perforation have occurred. Because all cases included in the reinforced group were from 2016 to 2020, we cannot eliminate the possibility that the difference in results between the 2 groups was because of procedural proficiency of the surgeons. Second, this was a retrospective study. Third, because of the small sample size, multivariate analysis of risk factors for the occurrence of graft duodenal perforation was not performed. Fourth, the possibility of late-onset graft perforation with this technique was not considered because of the short follow-up period. Finally, the cost of using the device was not addressed. However, if the device is effective in preventing graft duodenal perforation, which requires a prolonged hospital stay, the increased cost of the device will not be a major issue. Further large-scale, long-term studies are required to address the above limitations.
In bench surgery for pancreas transplant, the technique of stapling both ends of the graft duodenum with a reinforced stapler reduced the risk of graft duodenal perforation, a major complication after pancreas transplant. This simple and effective method requires only a change of device and does not require any special techniques.
Volume : 20
Issue : 6
Pages : 595 - 601
DOI : 10.6002/ect.2022.0126
From the Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
Acknowledgements: The authors thank Ms. Yasuka Ogawa (medical assistant) for data collection. We also thank Rebecca Tollefson, DVM, from Edanz Group (https://en-author-services.edanz.com/ac) for editing a draft of this manuscript. The authors have not received any funding or grants in support of the presented research or for the preparation of this work. Masafumi Nakamura received scholarship and honorarium from Covidien. The other authors have no conflicts of interest to disclose.
Corresponding author: Masafumi Nakamura, Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Phone: +81 92 642 5441
Experimental and Clinical Transplantation (2022) 6: 595-601
Figure 1. Cut Line on Proximal Side Set Just Beyond the Pylorus
Figure 2. Cut Line on Distal Side Set at the Third Portion of the Duodenum
Figure 3. Overall View of Pancreas Graft After Completion of Bench Surgery
Table 1. Recipient and Donor Characteristics
Table 2. Perioperative Factors and Postoperative Course in Recipients
Figure 4. Overall Pancreas Graft Survival After Transplant in Reinforced Group and Conventional Group
Table 3. Odds Ratios for Occurrence of Graft Duodenal Perforation