LETTER TO THE EDITOR Operative Drainage Following Pancreatic Resections: We Need More Evidence
tricular arrhythmias, which raises the question of preoperative cardiac disease). However, even if this postoperative mortality rate is low, it is still significantly higher than that of the drain group (∼80% of the deaths, 11 of 14, occurred in the no-drain group), and this difference should not be disregarded. Given that the overall morbidity was lower in the nodrain group, the higher mortality rate for this group could be interpreted as a higher rate of deadly complications (grade 5 morbidity). In other words, each patient could have a lower risk of complications, but each complication could place the patient at a higher risk. We must admit that in our department, we always use operative drainage, so we are what are referred to as “dogmatic surgeons.” The article by Correa-Gallego et al is another outstanding report from the Sloan-Kettering Cancer Center, and it forces us to challenge our practice of routine drainage. However, until other prospective randomized trials clarify the risk of death after a nondrained pancreatoduodenectomy, we believe that a selective drainage policy should be adopted very carefully. Nicola Zanini, MD Raffaele Lombardi, MD Department of Surgery Maggiore Hospital Bologna, Italy General and Thoracic Surgery Istituto Ortopedico Rizzoli Bologna, Italy
To The Editor: e have read with great interest the article, “Operative Drainage Following Pancreatic Resection: Analysis of 1122 Patients Resected Over 5 Years at a Single Institution,” by Correa-Gallego et al.1 This is a retrospective analysis focusing on the operative drain policy after pancreatic resections performed at a high-volume surgical center (Memorial Sloan-Kettering Cancer Center, New York, NY). It is a sort of feedback analysis in the light of the 2001 prospective randomized trial, which was conducted at the same institute and reported impressive positive postoperative outcomes of a no-drain policy after pancreatic resections.2 The results from the Sloan-Kettering Center show that the placement of drains at the initial operation was not associated with decreased postoperative procedures, readmission rates, reoperative rates, and overall morbidity. Moreover, the placement of drains may be associated with higher rates of infectious complications. These results, of course, strongly support the argument in favor of the no-drain policy or, at least, of a selective drainage policy. However, one issue raises our concern. Postoperative mortality after pancreatoduodenectomy is reported to be significantly higher in the “no-drain group” than in the “drain group” (3% vs 1%; P = 0.02). Because the authors did not comment on this result in the article, we have considered this aspect of the article and found possible explanations. It is probable that this higher postoperative mortality occurred as a matter of chance. After all, a postoperative mortality rate of 3% after pancreatoduodenectomy (11 deaths out of 353 patients) should be considered an acceptable, even admirable, rate in a pancreatic surgical center dealing with complex cases. Indeed, because the difference was found to be significant on univariate analysis, 1 or more confounding variables may have played a role (3 of 14 deaths were the consequence of ven-
e appreciate the opportune comments from Drs Zanini, Lombardi, Masetti, and Jovine regarding the difference in opera-
Disclosure: The authors declare no conflicts of interest. C 2014 Wolters Kluwer Health, Inc. All Copyright rights reserved. ISSN: 0003-4932/14/26106-e0160 DOI: 10.1097/SLA.0000000000000539
Disclosure: The authors declare no conflicts of interest. DOI: 10.1097/SLA.0000000000000540
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e160 | www.annalsofsurgery.com
Michele Masetti, MD Elio Jovine, MD Department of Surgery Maggiore Hospital Bologna, Italy [email protected]
REFERENCES 1. Correa-Gallego C, Brennan MF, D´angelica M, et al. Operative drainage following pancreatic resection: analysis of 1122 patients resected over 5 years at a single institution. Ann Surg. 2013;258:1051– 1058. 2. Conlon KC, Labow D, Leung D, et al. Prospective randomized clinical trial of the value of intraperitoneal drainage after pancreatic resection. Ann Surg. 2001;234:487–493; discussion 493–494.
Reply:
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tive mortality between patients who had operative drains after pancreaticoduodenectomy (drained) and those who did not (undrained) in our previously published article, “Operative Drainage Following Pancreatic Resection: Analysis of 1122 Patients Resected Over 5 Years at a Single Institution.” As the authors point out, although drained patients did not experience fewer complications (and no better control of pancreatic fistulae), in our series, undrained patients experienced a higher mortality rate (3% vs 1%; P = 0.02). Although we initially attributed the findings to statistical chance, their comments prompted us to look back at our data and analyze the specific cause of death in these 14 patients and whether they were related to postoperative pancreatic fistulae (POPFs—the outcome most likely to be influenced by the presence of drains). As it is reported in our article, the causes of death for these patients were: multiple organ failure (MOF) of different etiologies (8/14), ventricular arrhythmia (3/14), liver failure (1/14), gastrointestinal bleeding (1/14), and bronchial aspiration (1/14). Eleven of these fourteen patients did not have operative drains. Within this group, however, only 5 of 14 patients had a POPF (3/11 undrained and 2/3 drained). The cause of death was MOF in the 3 patients in the undrained group, and 1 case of MOF and 1 case of lethal ventricular arrhythmia in the 2 patients in the drained group. Although it is certainly plausible that MOF presents as a consequence of an uncontrolled POPF, approximately three fourths of patients who died in the undrained group did so in the absence of a pancreatic complication. In conclusion, although the observed association may be statistically significant, it is a small difference for which we could not identify any possible association with the lack of an operative drain. This may certainly represent a spurious statistical artifact, perhaps as a result of multiple hypothesis testing that increases the chance of type I errors. Nevertheless, a mortality rate of 3% after pancreaticoduodenectomy, as the authors also pointed out, is in line with previously published series from referral institutions around the world. Camilo Correa-Gallego, MD Peter J. Allen, MD Memorial Sloan-Kettering Cancer Center New York, NY
Annals of Surgery r Volume 261, Number 6, June 2015
Copyright © 2014 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
tricular arrhythmias, which raises the question of preoperative cardiac disease). However, even if this postoperative mortality rate is low, it is still significantly higher than that of the drain group (∼80% of the deaths, 11 of 14, occurred in the no-drain group), and this difference should not be disregarded. Given that the overall morbidity was lower in the nodrain group, the higher mortality rate for this group could be interpreted as a higher rate of deadly complications (grade 5 morbidity). In other words, each patient could have a lower risk of complications, but each complication could place the patient at a higher risk. We must admit that in our department, we always use operative drainage, so we are what are referred to as “dogmatic surgeons.” The article by Correa-Gallego et al is another outstanding report from the Sloan-Kettering Cancer Center, and it forces us to challenge our practice of routine drainage. However, until other prospective randomized trials clarify the risk of death after a nondrained pancreatoduodenectomy, we believe that a selective drainage policy should be adopted very carefully. Nicola Zanini, MD Raffaele Lombardi, MD Department of Surgery Maggiore Hospital Bologna, Italy General and Thoracic Surgery Istituto Ortopedico Rizzoli Bologna, Italy
To The Editor: e have read with great interest the article, “Operative Drainage Following Pancreatic Resection: Analysis of 1122 Patients Resected Over 5 Years at a Single Institution,” by Correa-Gallego et al.1 This is a retrospective analysis focusing on the operative drain policy after pancreatic resections performed at a high-volume surgical center (Memorial Sloan-Kettering Cancer Center, New York, NY). It is a sort of feedback analysis in the light of the 2001 prospective randomized trial, which was conducted at the same institute and reported impressive positive postoperative outcomes of a no-drain policy after pancreatic resections.2 The results from the Sloan-Kettering Center show that the placement of drains at the initial operation was not associated with decreased postoperative procedures, readmission rates, reoperative rates, and overall morbidity. Moreover, the placement of drains may be associated with higher rates of infectious complications. These results, of course, strongly support the argument in favor of the no-drain policy or, at least, of a selective drainage policy. However, one issue raises our concern. Postoperative mortality after pancreatoduodenectomy is reported to be significantly higher in the “no-drain group” than in the “drain group” (3% vs 1%; P = 0.02). Because the authors did not comment on this result in the article, we have considered this aspect of the article and found possible explanations. It is probable that this higher postoperative mortality occurred as a matter of chance. After all, a postoperative mortality rate of 3% after pancreatoduodenectomy (11 deaths out of 353 patients) should be considered an acceptable, even admirable, rate in a pancreatic surgical center dealing with complex cases. Indeed, because the difference was found to be significant on univariate analysis, 1 or more confounding variables may have played a role (3 of 14 deaths were the consequence of ven-
e appreciate the opportune comments from Drs Zanini, Lombardi, Masetti, and Jovine regarding the difference in opera-
Disclosure: The authors declare no conflicts of interest. C 2014 Wolters Kluwer Health, Inc. All Copyright rights reserved. ISSN: 0003-4932/14/26106-e0160 DOI: 10.1097/SLA.0000000000000539
Disclosure: The authors declare no conflicts of interest. DOI: 10.1097/SLA.0000000000000540
W
e160 | www.annalsofsurgery.com
Michele Masetti, MD Elio Jovine, MD Department of Surgery Maggiore Hospital Bologna, Italy [email protected]
REFERENCES 1. Correa-Gallego C, Brennan MF, D´angelica M, et al. Operative drainage following pancreatic resection: analysis of 1122 patients resected over 5 years at a single institution. Ann Surg. 2013;258:1051– 1058. 2. Conlon KC, Labow D, Leung D, et al. Prospective randomized clinical trial of the value of intraperitoneal drainage after pancreatic resection. Ann Surg. 2001;234:487–493; discussion 493–494.
Reply:
W
tive mortality between patients who had operative drains after pancreaticoduodenectomy (drained) and those who did not (undrained) in our previously published article, “Operative Drainage Following Pancreatic Resection: Analysis of 1122 Patients Resected Over 5 Years at a Single Institution.” As the authors point out, although drained patients did not experience fewer complications (and no better control of pancreatic fistulae), in our series, undrained patients experienced a higher mortality rate (3% vs 1%; P = 0.02). Although we initially attributed the findings to statistical chance, their comments prompted us to look back at our data and analyze the specific cause of death in these 14 patients and whether they were related to postoperative pancreatic fistulae (POPFs—the outcome most likely to be influenced by the presence of drains). As it is reported in our article, the causes of death for these patients were: multiple organ failure (MOF) of different etiologies (8/14), ventricular arrhythmia (3/14), liver failure (1/14), gastrointestinal bleeding (1/14), and bronchial aspiration (1/14). Eleven of these fourteen patients did not have operative drains. Within this group, however, only 5 of 14 patients had a POPF (3/11 undrained and 2/3 drained). The cause of death was MOF in the 3 patients in the undrained group, and 1 case of MOF and 1 case of lethal ventricular arrhythmia in the 2 patients in the drained group. Although it is certainly plausible that MOF presents as a consequence of an uncontrolled POPF, approximately three fourths of patients who died in the undrained group did so in the absence of a pancreatic complication. In conclusion, although the observed association may be statistically significant, it is a small difference for which we could not identify any possible association with the lack of an operative drain. This may certainly represent a spurious statistical artifact, perhaps as a result of multiple hypothesis testing that increases the chance of type I errors. Nevertheless, a mortality rate of 3% after pancreaticoduodenectomy, as the authors also pointed out, is in line with previously published series from referral institutions around the world. Camilo Correa-Gallego, MD Peter J. Allen, MD Memorial Sloan-Kettering Cancer Center New York, NY
Annals of Surgery r Volume 261, Number 6, June 2015
Copyright © 2014 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
