Journal of Gastrointestinal Surgery

, Volume 15, Issue 1, pp 184–190

Complex Pancreatic Surgery: Safety and Feasibility in the Community Setting

Authors

    • Department of SurgerySaint Barnabas Medical Center
    • St. George’s University School of Medicine
    • Department of SurgeryUniversity of Medicine and Dentistry of New Jersey
  • Matthew Tichauer
    • Department of SurgerySaint Barnabas Medical Center
    • St. George’s University School of Medicine
  • Zachary Klaassen
    • Department of SurgerySaint Barnabas Medical Center
    • St. George’s University School of Medicine
  • Prakash R. Paragi
    • Department of SurgerySaint Barnabas Medical Center
Original Article

DOI: 10.1007/s11605-010-1305-9

Cite this article as:
Chamberlain, R.S., Tichauer, M., Klaassen, Z. et al. J Gastrointest Surg (2011) 15: 184. doi:10.1007/s11605-010-1305-9

Abstract

Introduction

Advances in technology, innovative surgical procedures, and enhanced perioperative care have allowed more patients to be considered for complex pancreatic surgery. Published reports on the outcomes of pancreatic surgery performed at high volume tertiary referral centers have yielded excellent results. However, similar outcome and safety data from community hospitals is limited.

Material and Methods

Consecutive complex pancreatic surgery performed by a single surgeon from December 2004 to December 2009 formed the study group. Factors analyzed included patient demographics, operative procedure, operative time, length of hospital stay, pathology, and 30-day morbidity and mortality.

Results

One hundred and nine consecutive patients underwent pancreatic surgery, with a mean patient age of 62.4 ± 15.2 years. Eighty-three patients (76.1%) underwent definitive surgical procedure and 26 patients (23.9%) had palliative bypass after failed palliative biliary stenting. The mean operative time was 229 ± 109 min, the mean length of stay was 8.6 ± 6.5 days and 24 (22.0%) patients had surgical complications.

Conclusion

Complex pancreatic surgery can be performed safely at high-volume tertiary community hospitals with excellent outcomes comparable to tertiary academic centers. In the ongoing debate about the need for mandatory referral of complex surgical procedures, tertiary community hospitals with well-determined outcomes should be included.

Keywords

Pancreatic surgeryCommunity hospitalSurgical outcomes

Introduction

The natural history of pancreatic cancer, including its clinical quiescence and aggressive molecular epidemiology, plays an important role in its lethality. Surgical resection is the only curative option for patients with pancreatic cancer, yet it is associated with a high morbidity rate and disappointing 5-year survival rates of 10–29%.1 Up to 85% of patients with pancreatic cancer are unresectable at the time of diagnosis, and the significant morbidity and limited survival rates associated with complex pancreatic surgery has led some to question the rationale of radical operations for pancreatic cancer.28 In view of these facts, and given the complexity of surgical procedures required to treat pancreatic cancer, regionalization of complex pancreatic procedures such as pancreaticoduodenectomy (PD), has been proposed in an effort to optimize patient outcomes.915 Previous reports have suggested that hospital procedure volume is associated with superior clinical outcomes in patients undergoing complex operations, such as pancreatectomy and esophagectomy, as well as less complex procedures such as lumpectomy and colectomy.12,1618 Yet, contrary to these claims, others have reported no association between hospital volume and clinical outcome.19 For example, Enzinger et al.19 examined the relationship between hospital volume and clinical outcomes following gastrectomy among 306 US hospitals, and found no significant differences in 5-year overall survival or disease-free survival (short-term perioperative morbidity and mortality was not addressed) between low, moderate, and high volume hospitals.

Over the last two decades, significant advances in perioperative evaluation and patient selection, improved surgical techniques with combined regional and general anesthesia, and standard perioperative care and management have significantly reduced the mortality associated with pancreatic resection.1 While sporadic reports of excellent clinical outcomes for PD performed at low volume hospitals have emerged, they are few in number.9,19,20 Focusing exclusively on hospital volume, few studies have addressed the question as to whether patient outcomes are more dependent upon the surgeon’s experience/training or the hospital setting in which they are performed. In order to address this question, we sought to analyze our early experience with complex pancreatic surgery performed by a single fellowship-trained hepatobiliary and pancreatic surgeon after the establishment of a community-based hepatobiliary and pancreatic surgery Center of Excellence.

Materials and Methods

Over 350 patients with complex pancreatic problems were evaluated by the surgical oncology service at the Saint Barnabas Medical Center (SBMC), Livingston, New Jersey, from December 2004 and December 2009. Patients with hepatobiliary diseases were excluded from this analysis. One hundred and nine consecutive patients requiring pancreatic surgery formed the study group. All patients who underwent pancreatic resection had preoperative imaging with triple phase contrast-enhanced computed tomography or magnetic resonance imaging, along with positron emission tomography scans when appropriate. Diagnostic laparoscopy was performed in all malignant cases in order to exclude the presence of occult or disseminated intra abdominal disease. Intraoperative ultrasound was used selectively.

SBMC is a 641-bed tertiary-care referral hospital for a network of six community hospitals. The hospital performs more than 29,000 surgical cases per year and has an Accreditation Council for Graduate Medical Education-approved general surgery residency program. SBMC offers a comprehensive cancer program including one of the largest radiation oncology programs in northern New Jersey, treating more than 1,000 patients yearly. Furthermore, the facility operates a highly specialized Gastrointestinal Cancer Program, offering advanced therapeutic alternatives including: selective internal radiation therapy for inoperable liver cancer, radiofrequency and microwave ablation, heated intraperitoneal chemotherapy for advanced tumors of the peritoneal cavity, and robotic surgery. All cases are subject to multi-discipline review and analysis prior to initiation of therapy.

Data from patients who underwent surgical intervention were collected prospectively from medical records, outpatient charts, lab records, and pathology reports and entered into a Microsoft Excel database (Microsoft Corporation™, Redmond, WA, USA). Pre-operative evaluation included physical examination, medical/cardiac clearance, pertinent laboratory and imaging studies, and tumor markers. The operative procedure, operative time, estimated blood loss, length of hospital stay, and 30-day morbidity and mortality were analyzed. Procedures involving pancreatic resection had surgical margin analysis reported as R0 (negative), R1 (microscopically positive), and R2 (grossly positive). The association of continuous variables was statistically analyzed by the Student t test.

Results

Demographics

One hundred and nine patients underwent complex pancreatic surgical procedures for malignant, premalignant, or benign conditions. The mean age of all patients was 62.4 ± 15.2 (range: 33–87) with a male to female ratio of 1.4:1. Sixty-seven (61.5%) patients had pre-existing comorbidities (Table 1) with hypertension being the most common (N = 62, 56.9%). Additional common co-morbidities included diabetes mellitus (N = 30, 27.5%), coronary artery disease (N = 20, 18.3%) and chronic obstructive pulmonary disease (N = 3, 2.8%). Mean laboratory values for pre-operative bilirubin, pre-operative albumin, post-operative bilirubin, and post-operative albumin were 3.1 ± 5.5, 3.9 ± 0.9, 1.5 ± 1.9, and 3.1 ± 0.7 mg/dL, respectively.
Table 1

Comordities among 109 patients undergoing complex pancreatic procedures

All Patients (N = 109)

PD Patients (N = 40)

Comorbidity

N (%)

Comorbidity

N (%)

HTN

62 (56.9)

HTN

24 (60.0)

DM

30 (27.5)

DM

9 (22.5)

CAD

20 (18.3)

CAD

8 (20.0)

COPD

3 (2.8)

COPD

1 (2.5)

Sixty seven patients (61.5%) undergoing complex pancreatic procedures had a comorbidity, with hypertension (N = 62, 56.9%) and diabetes mellitus (N = 30, 27.5%) being the most common. Twenty-six patients (65.0%) undergoing PD had a comorbidity, with hypertension (N = 24, 60.0%) and diabetes mellitus (N = 9, 22.5%) being the most common

PD Pancreaticoduodenectomy, HTN Hypertension, DM Diabetes mellitus, CAD Coronary artery disease, COPD Chronic obstructive airway disease

Diagnoses

Sixty-one patients (56.0%) had pancreatic pathology located within the head or uncinate process of the pancreas 20 patients (18.3%) had pathology in the ampullary/periampullary region, 19 patients (17.4%) had pathology in the body, and nine patients (8.3%) had pathology in the tail of the pancreas (Table 2).
Table 2

Location of the resected pancreatic pathology

Anatomical location

N (%)

Head/uncinate process

61 (56.0)

aAmpullary/periampullary

20 (18.3)

Body

19 (17.4)

Tail

9 (8.3)

The head of the pancreas (N = 61, 56.0%) was the most common location for resected pancreatic lesions

aIncludes duodenal, ampullary and distal common bile duct tumors

The most common pancreatic pathology identified was 55 (50.5%) cases of ductal adenocarcinoma and 12 (11.0%) cases of intraductal papillary mucinous tumors. There were six cases (5.5%) of neuroendocrine tumor (NET), five cases (4.6%) of focal sclerosing pancreatitis, three cases (2.8%) of solid pseudo-papillary tumors of the pancreas, two cases (1.8%) each of lymphoepithelial cyst of the pancreas, pancreatic pseudocyst and duodenal villous adenoma, in addition to isolated cases (0.9%) of a mucinous carcinoma peritonei, necrotizing pancreatitis, and ruptured splenic artery aneurysm (Table 3). Ampullary/periampullary pathology (N = 19, 17.4%) included nine cases (8.3%) of adenocarcinoma, four cases (3.7%) of tubulovillus adenoma, three cases (2.8%) of cholangiocarcinoma, two cases (1.8%) of D2-duodenal cancer, and a single case (0.9%) of duodenal ulcer with obstruction. The head of the pancreas was the most common site for pancreatic adenocarcinoma consisting of 19 (34.5%) cases. Among the six cases (5.5%) of NET, three involved the body (50.0%), two involved the head (33.3%), and one involved the tail (16.7%) of the pancreas.
Table 3

Histopathology of pancreatic resections

Pancreatic pathology

N (%)

Adenocarcinoma

55 (50.5)

IMPT

12 (11.0)

NET

6 (5.5)

Focal sclerosing pancreatitis

5 (4.6)

Pseudo papillary tumor

3 (2.8)

Lymphoepithelial cyst

2 (1.8)

Pseudocyst

2 (1.8)

Adenoma

2 (1.8)

Necrotizing pancreatitis

1 (0.9)

Mucinous carcinoma peritonei

1 (0.9)

Ruptured splenic artery aneurysm

1 (0.9)

Ampullary/periampullary pathology

Adenocarcinoma

9 (8.3)

Tubulovillus adenoma

4 (3.7)

Cholangiocarcinoma

3 (2.8)

D2-Duodenal cancer

2 (1.8)

Ulcer and stricture

1 (0.9)

The most common resected pathology were pancreatic adenocarcinoma (N = 55, 50.5%), IMPT (N = 12, 11.0%), ampullary/periampullary adenocarcinoma (N = 9, 8.3%), NET (N = 6, 5.5%), and focal sclerosing pancreatitis (N = 5, 4.6%)

IPMT Intraductal papillary mucinous tumor, NET Neuro endocrine tumor

Surgical Procedures

Eighty-three patients (76.1%) underwent a definitive surgical procedure and 26 patients (23.9%) had palliative procedures and biopsy after failed palliative biliary stenting for obstructive jaundice or as a result the determination of unresectability at the time of laparotomy (Table 4). Forty patients underwent PD (36.7%) including three concomitant portal vein resections and a single case of concomitant partial hepatectomy (segments 6 and 8) for metastatic neuroendocrine tumor. Among 32 patients who underwent PD for malignant disease, 11 patients (34.4%) had stage I disease, 17 patients (53.1%) had stage II disease, and four patients (12.5%) had stage III disease. Four patients underwent total pancreatectomy (3.7%), with one patient undergoing a simultaneous resection of hepatic segments 2 and 6 for metastatic neuroendocrine tumor of the head and body. One patient undergoing total pancreatectomy had pancreatic cancer in the uncinate process and pre-existing dorsal agenesis of the pancreas. Fifteen patients underwent subtotal pancreatectomy (13.8%) and nine patients (8.3%) underwent distal pancreatectomy. Among this group, six patients underwent open resection and three patients underwent laparoscopic resection. Additional procedures included: diagnostic laparoscopy and pancreatic biopsy (N = 7, 6.4%), enteric drainage of a pseudocyst (N = 4, 3.7%), tumor enucleation for solid pseudopapillary tumor (N = 2, 1.8%) and one case (0.9%) each of a Puestow procedure and pancreatic sparing duodenectomy. Among the 68 cases of pancreatic resection, 67 patients (98.5%) achieved a R0 margin, one patient (1.5%) had R1 margins, and no patient had R2 margins of resection.
Table 4

Pancreatic procedures performed in 109 consecutive patients

Procedure

N (%)

Pancreaticoduodenectomy

40 (36.7)

Palliative bypass and biopsy

26 (23.9)

Subtotal pancreatectomy

15 (13.8)

Distal pancreatectomy

9 (8.3)

Diagnostic laparoscopy and biopsy

7 (6.4)

Total pancreatectomy

4 (3.7)

Internal Pseudocyst enteric drainage

4 (3.7)

Pancreatic Enucleation

2 (1.8)

Puestow procedure

1 (0.9)

Pancreas sparing duodenectomy

1 (0.9)

Pancreatic procedures performed included pancreaticoduodenectomy (N = 40, 36.7%), palliative bypass and biopsy (N = 26, 23.9%), subtotal pancreatectomy (N = 15, 13.8%) and distal pancreatectomy (N = 9, 8.3%)

Peri-operative Results

Mean operative time for all pancreatic resection patients was 229 ± 109 vs. 326 ± 64 min for the PD patients. Estimated blood loss for all pancreatic resection patients was 242 ± 272 vs. 248 ± 155 mL for PD patients. Hospital LOS for all pancreatic resection patients was 8.6 ± 6.5 vs. 11.2 ± 7.7 days for PD patients. There was one peri-operative 30-day mortality due to cardiac arrest on postoperative day 12 in a 75-year-old female who underwent a palliative double bypass procedure for unresectable pancreatic adenocarcinoma. Twenty-four (22.0%) of 109 patients suffered peri-operative complications (Table 5), with the most common complication being wound infection (N = 6, 5.5%). Among the 40 patients undergoing PD, 15 patients (37.5%) suffered complications, with the most common complication being wound infection (N = 5, 12.5%). Five patients (4.6%) underwent reoperation, three (7.5%) of which had undergone PD.
Table 5

Postoperative complications in 109 patients undergoing pancreatic surgery

All patients (N = 109)

PD patients (N = 40)

Complication

N (%)

Complication

N (%)

Wound infection

6 (5.5)

Wound infection

5 (12.5)

Reoperation

5 (4.6)

Reoperation

3 (7.5)

Cholangitis/Sepsis

4 (3.7)

Cholangitis/sepsis

3 (7.5)

RS Infection/PE

3 (2.8)

RS infection/PE

2 (5.0)

Intra-abdominal abscess

2 (1.8)

Intra-abdominal abscess

1 (2.5)

Biliary leak

2 (1.8)

Biliary leak

2 (5.0)

Gastric outlet obstruction

2 (1.8)

Gastric outlet obstruction

1 (2.5)

Angina

1 (0.9)

Angina

0

Death

1 (0.9)

Death

0

Total

26 (23.9)a

Total

17 (42.5)b

Twenty-eight patients (25.7%) undergoing pancreatic surgery had 32 (29.4%) complications, with wound infection (N = 6, 5.5%) being the most common. Sixteen patients (40.0%) undergoing PD had 19 (47.5%) complications, with wound infection (N = 5, 12.5%) and cholangitis/sepsis (N = 3, 7.5%) being the most common

PD pancreaticoduodenectomy, RS Respiratory infection, GI Gastro intestinal, PE Pulmonary embolism

a26 complications occurring in 24 patients (22.0%)

b17 complications occurring in 15 patients (37.5%)

Discussion

The converse relationship between hospital volume and postoperative mortality among patients undergoing complex surgical procedures, including pancreatic resection, have been extensively examined and documented.9,21,22 The Donabedian Model is a framework for quality-of-care,23 developed to define, measure, and categorize quality in healthcare delivery. This model includes: structure (where the care is delivered), process (evaluating medical practice), and outcome (impact of care on health).23 The outcome measure, which reflects how a unique patient fares following some form of medical intervention is the most difficult to measure. Although hospital volume is simple to measure and may be associated with improved patient outcomes for pancreatic resection and other procedures,2126 it may not be the sole determinant of outcome.

Many high-volume pancreatic centers throughout the country have reported substantial reduction in hospital mortality over the last 10 years,15,26 which is attributable to a variety of factors. Factors most often cited include the volume of procedures performed, perioperative care and nutrition, and strict adherence to critical care and perioperative pathways.12,22,24 Mukherjee et al.15 evaluated the impact of the UK Cancer Outcome Guidelines (COG) among 140 patients who underwent PD between 1999 and 2006. The COG was introduced in the UK in 1999 and was subsequently implemented in 2003. The institution of these guidelines led to the centralization of cancer services, including upper gastrointestinal cancer services and was restricted to tertiary referral centers.27 In the pre-COG era (1999–2002) there were 41 PD performed compared to 99 performed in the post-COG era (2003–2006).15 The authors reported a trend towards decreased mortality (9.7–5.0%, p < 0.448) and morbidity (41.6–35.3%, p < 0.565), concluding that the COG implementation lead to increased PD volume, higher staffing levels, and a trend towards better outcomes.15

Birkmeyer et al.11 evaluated outcomes based on hospital volume among Medicare patients undergoing PD for pancreatic cancer and reported that more than 50% of these patients received care at hospitals performing fewer than two procedures per year. They evaluated outcomes based on four hospital volume categories, which included very low (<1 case per year), low (1–1.99 cases per year), medium (2–4.99 cases per year), and high volume hospitals (>5 cases per year). These authors reported that in-hospital mortality rates at low and very low-volume hospitals were three- to fourfold higher than at high-volume hospitals (12% and 16%, respectively, vs. 4%, p < 0.001) and concluded that hospital volume is an important factor in surgical outcomes for PD.11

In an attempt to identify factors affecting outcomes after complex pancreatic surgery as well as to trace the evolution of a procedure, Cameron et al.26 reported their 30-year experience involving 1,000 consecutive PD at the Johns Hopkins Hospital. They noted that advancements over the last three decades in imaging, intraoperative anesthesia, and peri-operative care were major factors resulting in improved patient outcomes and decreased perioperative morbidity and mortality. These authors also noted a 50% reduction in their operative time and a 30% reduction in estimated operative blood loss over the study period.26

Meguid et al.28 conducted a retrospective analysis of 7,558 patients who underwent pancreatic resection from the Nationwide Inpatient Sample (20% sample of patients in the US from 1998 to 2003). This study reported a median annual institution pancreatic resection volume of 15 cases, mean in-hospital mortality of 7.6% and noted that based on a goodness-of-fit analysis, a minimum of 19 pancreatic resections per year is required to qualify as a high volume center.28 However, they concluded that a volume cutoff for pancreatic surgery was arbitrary, as a difference in perioperative mortality was observed regardless of the volume cutoff used.28 Riall et al.29 reviewed the Texas Hospital Inpatient Discharge Database from 1999 to 2005 and identified 12 high-volume hospitals for pancreatic resection (>11 cases/year). Among these hospitals, there was significant variability in mortality, duration of stay, need for ongoing nursing care, operation within 24 h of admission, and hospital cost per patient visit.29 They concluded that significant variability in outcomes occurred even among high-volume providers and reasoned that individual hospital differences likely accounted for much of the variability not explained by hospital volume.29

In addition to variability in outcomes at high-volume centers, a number of studies from low-volume and community-based hospitals have reported excellent outcomes. Schell et al.25 performed a comparative outcome analysis of 369 patients who underwent PD at the University of California, San Francisco affiliated hospitals between October 1989 and June 2003. They noted that while high-volume centers did attain excellent surgical outcomes, smaller and lower-volume hospitals achieved similar surgical outcomes provided they import expertise and implement care pathways. The low-volume hospital group consisted of community-based hospitals and county general hospitals that performed an average of one PD per year, and a Veterans Affairs Medical Center that performed three PD per year. The high volume tertiary hospitals averaged 23 PD per year. They found no difference in regards to morbidity and complications between the groups (high volume, 58.8% vs. low volume, 60.3%; p < 0.579). Moreover, the perioperative mortality rates for patients undergoing PD were approximately 4% in both groups, with no significant difference in 5-year survival rates (high-volume hospital 19% versus 18.3% for low-volume hospital group, p < 0.096).25

The largest published community based study for complex pancreatic surgery to date is by Hoshal et al.30 who reported their experience with 134 consecutive PD performed between 1985 and 2002. They reported an overall mortality of 3.7%, identified 60 major complications occurring in 38 patients (28%) and the need for reoperation in five patients (3.7%). The volume of pancreatic cases at the tertiary community hospital reported in the current report places us in a high volume group with an average of more than 20 complex pancreatic cases per year. All 109 cases in the current study were performed by a single surgeon (RSC), which provides for uniformity in operative technique and post-operative management. We acknowledge that our surgical margin data may be greater than expected, however, as Table 6 demonstrates, the results achieved are comparable to those published by high-volume university hospitals 15,25,26 and other community hospitals.30 These results provide more data to support the notion that additional factors such as surgical experience and proper patient selection may be more determinant of outcome than the absolute number of cases and/or the size of the hospital where the cases are performed.
Table 6

Comparative analysis of major tertiary academic centers and community hospital complex pancreatic surgical series

 

Chamberlain et al. [8]

Hoshal et al.30

Mukherjee et al.15

Schell et al.25

Cameron et al.26

SBMC

SJMH

RLH

ML

JHH

Number of Patients

109

134

140

301

1000

Time

12/2004–12/2009

1985–2002

1999–2006

1989–2003

1969–2003

Published

Present Study

2004

2009

2008

2006

Surgeon

Single

Single

Multiple

Multiple

Single

M:F

1.4:1

1.2:1

1.06:1

1:01

1.2:1

Mean Age

62.4 ± 15.2

60

64

61

63.4

Comorbidity (%)

67 (61.5)

N/A

N/A

N/A

N/A

Mean EBL

242 ± 272

950

N/A

1167 ± 1411

700

Mean Operative Time (min)

229 ± 109

348

N/A

402 ± 120

330

Operative Mortality

0

0

N/A

N/A

0

30-Day Mortality

0.9%

3.7%

2.8%

4%

1%

Complications (%)

24 (22.0)

38 (28.0)

52 (37.1)

177 (58.8)

410 (41.0)

Reoperation (%)

5 (4.6)

5 (3.7)

N/A

22 (7.3)

21 (2.1)

Mean LOS (days)

8.6 ± 6.5

9

16

16.1 ± 23.5

9

Outcomes comparing community-based reports (8 and 30) and tertiary academic centers are provided (15, 25, and 26). Results between these five studies are comparable in all outcome modalities, including EBL, operative mortality, 30-day mortality, complications, and length of stay

SBMC Saint Barnabas Medical Center, Livingston, New Jersey, SJMH Saint Joseph Mercy Hospital, Anne Arbor, Michigan, RLH Royal London Hospital, London, UK, ML Moffit-Long Hospital, San Francisco, California, JHH Johns Hopkins Hospital, Baltimore, Maryland, N/A not available, EBL estimated blood loss, LOS length of stay

Although hospital volume is easy to measure, it is not reliable as the sole measure of quality or outcomes after pancreatic surgery. The idea that volume alone can be a proxy to define centers of surgical excellence is an imperfect rationale. Despite emerging reports of excellent surgical outcomes for many complex procedures performed at community based medical centers, a movement towards establishing volume-based referral centers for certain surgical (including pancreatic) procedures continue to be pushed.20,31,32 The Leapfrog Group, comprised of healthcare purchasers and providers representing 33 million patients, is perhaps the most vocal group promoting volume-based referral. In order to concentrate patient care in high volume hospitals, the Leapfrog initiative has set annual hospital volume thresholds for a number of different surgical procedures including: coronary artery bypass graft (450 cases), coronary angioplasties (400 cases), abdominal aortic aneurysm repairs (50 cases), aortic valve replacements (120 cases), esophagectomies (13 cases), pancreatic resections (11 cases), and bariatric surgeries (125 cases).32 Whether there should be regionalization of major hepatobiliary–pancreatic procedures to academic centers of excellence is being similarly debated. Tertiary community based hospitals with excellent results should be included in any proposed mandatory referral system. To date, there remains no optimum combination of number of procedures, years of training, or other factors that assure good outcomes in surgery. Proper patient selection, in combination with a competent surgeon with adequate training, excellent critical care, and interdisciplinary support is the only means of optimizing patient outcome regardless of the hospital setting or procedure volume.

Acknowledgments

We thank N. Babel MD, R. Singh BSc, and J. Serfin BSc for their efforts with data collection and analysis.

Conflict of Interest

All the authors declare that there are no conflicts of interest and have accepted no financial sponsorship in producing and presenting this manuscript. Each author listed is in agreement with the content of the manuscript.

Copyright information

© The Society for Surgery of the Alimentary Tract 2010