LETTER TO THE EDITOR Predictors for Anastomotic Leak After Colorectal Resection To the Editor:
W
e read with great interest the study by Trencheva et al1 investigating predictive risk factors of anastomotic leakage (AL) in colorectal surgery. This clinical study is one of the few prospective studies whose primary aim is the analysis of predictive risk factors for AL in colorectal surgery. In this single-center nonrandomized observational study, 616 patients with mainly inflammatory and malignant pathologies of the colon and rectum undergoing large bowel resection by laparoscopic or hand-assisted laparoscopic or conventional surgery were enclosed. Besides the already known risk factors such as low anastomosis, male sex and intraoperative complications the authors identified the Charlson Comorbidity Index greater than or equal to 3 and the high ligation of inferior mesenteric artery as independent risk factors for AL. We fully agree with the authors that we need established guidelines for AL risk prediction and management. However, this study has significant limitations, so its value in achieving this goal is debatable. The authors analyzed an inhomogeneous patient population. The different disease spectrum including neoplasms (55.2%) of the colon and the rectum, inflammatory bowel diseases (16.4%), diverticulitis (14.0%), and other diseases (14.4%) such as appendicitis, small bowel obstruction, bowel perforation, and constipation requires a different surgical procedure with consequently different degree of surgical difficulty in both benign and malignant diseases as well as colon and rectal surgery. It is known that the AI for intraperitoneal anastomoses is significantly lower than for extraperitoneal anastomoses.2–4 In addition, patients with rectal cancer received neoadjuvant therapy, which has been identified by the authors themselves as a risk factor for AI in univariate analysis. Subgroup analysis of the different
Disclosure: The authors declare no conflicts of interest. C 2013 Wolters Kluwer Health, Inc. All Copyright rights reserved. ISSN: 0003-4932/13/26106-e0155 DOI: 10.1097/SLA.0000000000000458
patient populations that could have distorted the present results would rule out such a bias and greatly enhance the present results. Otherwise, there is a danger that potential risk factors for AL, especially in rectal surgery, could be underestimated. Finally, with a share of 1.6% in diabetic patients and an average body mass index of 25.9 kg/m2 , the patient selection seems not to be representative of US patients.5 Overall, the results of Trencheva et al confirm some of the risk factors for AL that are already known from mainly retrospective studies for both colon and rectum resections. Furthermore, they underline the need to identify independent AL risk factors in prospective studies to develop a predictive model of AL in colon and rectal surgery with recommendations for prevention and treatment. Sameer Dhayat, MD Norbert Senninger, MD, FACS, FRCS Department of General and Visceral Surgery University Hospital of Muenster Muenster, Germany [email protected]
REFERENCES 1. Trencheva K, Morrissey KP, Wells M, et al. Identifying important predictors for anastomotic leak after colon and rectal resection: prospective study on 616 patients. Ann Surg. 2013;257:108–113. 2. Kirchhoff P, Clavien PA, Hahnloser D. Complications in colorectal surgery: risk factors and preventive strategies. Patient Saf Surg. 2010;4:5. 3. K¨ockerling F, Rose J, Schneider C, et al. Laparoscopic colorectal anastomosis: risk of postoperative leakage. Results of a multicenter study. Laparoscopic Colorectal Surgery Study Group (LCSSG). Surg Endosc. 1999;13:639–644. 4. Alves A, Panis Y, Trancart D, et al. Factors associated with clinically significant anastomotic leakage after large bowel resection: multivariate analysis of 707 patients. World J Surg. 2002;26:499–502. 5. Finucane MM, Stevens GA, Cowan MJ, et al. National, regional, and global trends in body-mass index since 1980: systematic analysis of health examination surveys and epidemiological studies with 960 country-years and 9.1 million participants. Lancet. 2011;377:557–567.
Reply:
W
e thank Dr Sameer Dhayat and Dr Norbert Senninger for their comments about our study, “Identifying impor-
tant Predictors for Anastomotic Leak After Colon and Rectal Resection: Prospective Study on 616 Patients.”1 Although they essentially agree with our findings, they raise a concern that subgroup analyses were not reported and that our sample body mass index is not representative for the US population. With regard to these points, we certainly conducted subgroup regression analysis on different patient populations (rectal cancer, colon cancer, inflammatory bowel disease, J-pouch, and other groups) but given the sample sizes the results were not conclusive. In the rectal cancer group, we did not find neoadjuvant therapy to be a significant independent factor for anastomotic leak (P = 0.603). The strongest predictor for anastomotic leak in the rectal cancer group was the level of anastomosis below 10 cm from the anal verge. We agree with authors that our sample body mass index is not representative for the entire US population (this is a singlecenter study). However, the sample was composed of consecutive patients from the New York City area and thus is representative of the diverse patients who present to our institution. We appreciate the attention this important topic brings and hope to contribute with further studies on risk factors, prevention and management of anastomotic leak after colorectal resection. Koianka Trencheva, MS Kevin P. Morrissey, MD Martin Wells, PhD Carol A. Mancuso, MD Sang W. Lee, MD Toyooki Sonoda, MD Fabrizio Michelassi, MD Mary E. Charlson, MD Jeffrey W. Milsom, MD Weill Cornell Medical College New York, NY [email protected]
REFERENCE 1. Trencheva K, Morrissey KP, Wells M, et al. Identifying important predictors for anastomotic leak after colon and rectal resection: prospective study on 616 patients. Ann Surg. 2013;257: 108–113.
Disclosure: The authors declare no conflicts of interest. DOI: 10.1097/SLA.0000000000000457
Annals of Surgery r Volume 261, Number 6, June 2015
www.annalsofsurgery.com | e155
Copyright © 2013 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
W
e read with great interest the study by Trencheva et al1 investigating predictive risk factors of anastomotic leakage (AL) in colorectal surgery. This clinical study is one of the few prospective studies whose primary aim is the analysis of predictive risk factors for AL in colorectal surgery. In this single-center nonrandomized observational study, 616 patients with mainly inflammatory and malignant pathologies of the colon and rectum undergoing large bowel resection by laparoscopic or hand-assisted laparoscopic or conventional surgery were enclosed. Besides the already known risk factors such as low anastomosis, male sex and intraoperative complications the authors identified the Charlson Comorbidity Index greater than or equal to 3 and the high ligation of inferior mesenteric artery as independent risk factors for AL. We fully agree with the authors that we need established guidelines for AL risk prediction and management. However, this study has significant limitations, so its value in achieving this goal is debatable. The authors analyzed an inhomogeneous patient population. The different disease spectrum including neoplasms (55.2%) of the colon and the rectum, inflammatory bowel diseases (16.4%), diverticulitis (14.0%), and other diseases (14.4%) such as appendicitis, small bowel obstruction, bowel perforation, and constipation requires a different surgical procedure with consequently different degree of surgical difficulty in both benign and malignant diseases as well as colon and rectal surgery. It is known that the AI for intraperitoneal anastomoses is significantly lower than for extraperitoneal anastomoses.2–4 In addition, patients with rectal cancer received neoadjuvant therapy, which has been identified by the authors themselves as a risk factor for AI in univariate analysis. Subgroup analysis of the different
Disclosure: The authors declare no conflicts of interest. C 2013 Wolters Kluwer Health, Inc. All Copyright rights reserved. ISSN: 0003-4932/13/26106-e0155 DOI: 10.1097/SLA.0000000000000458
patient populations that could have distorted the present results would rule out such a bias and greatly enhance the present results. Otherwise, there is a danger that potential risk factors for AL, especially in rectal surgery, could be underestimated. Finally, with a share of 1.6% in diabetic patients and an average body mass index of 25.9 kg/m2 , the patient selection seems not to be representative of US patients.5 Overall, the results of Trencheva et al confirm some of the risk factors for AL that are already known from mainly retrospective studies for both colon and rectum resections. Furthermore, they underline the need to identify independent AL risk factors in prospective studies to develop a predictive model of AL in colon and rectal surgery with recommendations for prevention and treatment. Sameer Dhayat, MD Norbert Senninger, MD, FACS, FRCS Department of General and Visceral Surgery University Hospital of Muenster Muenster, Germany [email protected]
REFERENCES 1. Trencheva K, Morrissey KP, Wells M, et al. Identifying important predictors for anastomotic leak after colon and rectal resection: prospective study on 616 patients. Ann Surg. 2013;257:108–113. 2. Kirchhoff P, Clavien PA, Hahnloser D. Complications in colorectal surgery: risk factors and preventive strategies. Patient Saf Surg. 2010;4:5. 3. K¨ockerling F, Rose J, Schneider C, et al. Laparoscopic colorectal anastomosis: risk of postoperative leakage. Results of a multicenter study. Laparoscopic Colorectal Surgery Study Group (LCSSG). Surg Endosc. 1999;13:639–644. 4. Alves A, Panis Y, Trancart D, et al. Factors associated with clinically significant anastomotic leakage after large bowel resection: multivariate analysis of 707 patients. World J Surg. 2002;26:499–502. 5. Finucane MM, Stevens GA, Cowan MJ, et al. National, regional, and global trends in body-mass index since 1980: systematic analysis of health examination surveys and epidemiological studies with 960 country-years and 9.1 million participants. Lancet. 2011;377:557–567.
Reply:
W
e thank Dr Sameer Dhayat and Dr Norbert Senninger for their comments about our study, “Identifying impor-
tant Predictors for Anastomotic Leak After Colon and Rectal Resection: Prospective Study on 616 Patients.”1 Although they essentially agree with our findings, they raise a concern that subgroup analyses were not reported and that our sample body mass index is not representative for the US population. With regard to these points, we certainly conducted subgroup regression analysis on different patient populations (rectal cancer, colon cancer, inflammatory bowel disease, J-pouch, and other groups) but given the sample sizes the results were not conclusive. In the rectal cancer group, we did not find neoadjuvant therapy to be a significant independent factor for anastomotic leak (P = 0.603). The strongest predictor for anastomotic leak in the rectal cancer group was the level of anastomosis below 10 cm from the anal verge. We agree with authors that our sample body mass index is not representative for the entire US population (this is a singlecenter study). However, the sample was composed of consecutive patients from the New York City area and thus is representative of the diverse patients who present to our institution. We appreciate the attention this important topic brings and hope to contribute with further studies on risk factors, prevention and management of anastomotic leak after colorectal resection. Koianka Trencheva, MS Kevin P. Morrissey, MD Martin Wells, PhD Carol A. Mancuso, MD Sang W. Lee, MD Toyooki Sonoda, MD Fabrizio Michelassi, MD Mary E. Charlson, MD Jeffrey W. Milsom, MD Weill Cornell Medical College New York, NY [email protected]
REFERENCE 1. Trencheva K, Morrissey KP, Wells M, et al. Identifying important predictors for anastomotic leak after colon and rectal resection: prospective study on 616 patients. Ann Surg. 2013;257: 108–113.
Disclosure: The authors declare no conflicts of interest. DOI: 10.1097/SLA.0000000000000457
Annals of Surgery r Volume 261, Number 6, June 2015
www.annalsofsurgery.com | e155
Copyright © 2013 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
