Whipple or Pylorus Preservation? A Critical Reappraisal and Some New Insights Into Pancreaticoduodenectomy

The article “Outcome of pancreaticoduodenectomy with pylorus preservation or with antrectomy in the treatment of chronic pancreatitis” by Dr. Jimenez and colleagues from the Massachusetts General Hospital, ¹ is another outstanding demonstration that pancreaticoduodenectomy can be performed with a very low hospital mortality in referral centers doing high-volume pancreatic surgery. In this series, 72 consecutive patients undergoing pancreaticoduodenectomy for chronic pancreatitis over a 7-year period are reported, with only one death (in a high-risk complicated 66-year-old man with end-stage renal disease). Not long ago many would have considered pancreaticoduodenectomy to be inappropriate for patients with benign disease because of the substantial risks for mortality and high morbidity that followed this procedure. Now, however, in many pancreatic surgery centers, pancreaticoduodenectomy has become the operation of choice for patients with chronic pancreatitis who are not candidates for the Puestow procedure.

The current series of patients with chronic pancreatitis is unusual in that only 28% had alcohol as an etiology. Generally, in most large series of patients with chronic pancreatitis in the United States, alcohol consumption is the major etiology. In addition, a surprising number, 35%, had either ampullary stenosis or pancreas divisum, patients who are notoriously poor responders to any sort of pancreatic surgery. Finally, 26% were listed as idiopathic and for another 11% no etiology was given. I suspect many of the patients in the last two categories were individuals who presented with pain and a mass in the head of the pancreas, and were suspected of having cancer. After undergoing pancreaticoduodenectomy, with no malignancy detected, they were reclassified as chronic pancreatitis. The authors state that when chronic pancreatitis was felt to be the diagnosis, pylorus preservation was carried out. In those patients in whom cancer was suspected or in whom prior surgery precluded pylorus preservation, hemigastrectomy was carried out. The fact that hemigastrectomy, or the classic Whipple procedure, was performed in 33 patients suggests perhaps that many fell into the category of being operated on under the suspicion of cancer, not chronic pancreatitis.

The authors’ overall results were good, with 65% of the patients receiving substantial benefit from the operative procedure. Considering the large number of patients with ampullary stenosis and pancreas divisum, a group of patients who traditionally do not respond well to surgical therapy, these results are very good. However, the patients who were operated on with a mass in the head of the pancreas, who were over age 50, with a relatively short duration of pain, and who were suspected of having pancreatic cancer, obviously were highly likely to have a good result. Nevertheless, for their mix of patients, I think most would consider an overall good result of 65% acceptable.

One of the major goals of this paper was to compare patients who underwent pylorus preservation with those who underwent antrectomy, for the treatment of chronic pancreatitis. It may or may not be reasonable, however, to compare these two groups. Even though the study was presented as an experience with pancreaticoduodenectomy in the treatment of chronic pancreatitis, with almost equal numbers of patients treated with a standard Whipple and with pylorus-preserving pancreaticoduodenectomy, the indications were not identical. Pylorus-preserving pancreaticoduodenectomy was the preferred operation for patients suspected preoperatively of having chronic pancreatitis. A Whipple operation was performed for those patients operated on for a suspicion of cancer, when there was a history of peptic ulcer disease, or when previous gastric or pancreatic surgery precluded a pylorus-preserving pancreaticoduodenectomy. When the authors compared the demographics of the two patient populations—39 in the pylorus-preserving pancreaticoduodenectomy group, and 33 in the Whipple group—there were no statistically significant differences with these small numbers. However, these were two different populations of patients operated on for different indications, and whether or not it is fair to compare the two groups could be argued. Nevertheless, that is one of the major features of this article.

Interestingly, the outcomes were comparable in both groups with one exception, the incidence of delayed gastric emptying. As defined by the authors, this incidence was 33% after pylorus-preserving pancreaticoduodenectomy and only 12% in patients with a standard Whipple. The clinical importance of this nonlife-threatening complication is that it can extend hospital length of stay substantially. In this series, however, the average length of stay was extended only three days, and that barely reached statistical significance. Even though it was statistically significant, its clinical significance is debatable.

Delayed gastric emptying is a troublesome postoperative complication that can occur after various gastric procedures, including hemigastrectomy, gastrojejunostomy, pyloroplasty, or duodenojejunostomy as is performed after pylorus-preserving pancreaticoduodenectomy. The etiology of this complication in most settings is unclear. The addition of a vagotomy is a complicating feature that many feel plays a role. After pancreaticoduodenectomy, it has been our thought that the loss of motilin plays a major role. Motilin is a gastrointestinal hormone, produced almost entirely in the duodenum, which stimulates gastric peristalsis. When a pancreaticoduodenectomy (either pylorus-preserving or classic Whipple) is performed, virtually the entire duodenum is removed, and thus so is the source of motilin. The antibiotic erythromycin is a motilin agonist; in a prospective randomized study we published several years ago, ² the postoperative administration of erythromycin as a motilin agonist stimulated gastric emptying, which adds support to the concept that the loss of motilin has a role in the pathogenesis of delayed gastric emptying. In our experience, the incidence of delayed gastric emptying is identical after pancreaticoduodenectomy, whether or not pylorus preservation or a hemigastrectomy has been carried out. In a prospective randomized study comparing pylorus-preserving pancreaticoduodenectomy to a more radical Whipple procedure including hemigastrectomy and retroperitoneal lymphadenectomy, there was no significant difference in delayed gastric emptying in the two groups. ³ In a similar prospective randomized trial, presented at the Society for Surgery of the Alimentary Tract (Orlando, FL, May 17, 1999) by Markus Büchler, MD, of Berne, Switzerland, similar results were obtained. In this trial, patients undergoing a classic Whipple were compared to those undergoing pylorus-preserving pancreaticoduodenectomy for pancreatic cancer. The incidence of delayed gastric emptying was identical in both groups. This complication remains an enigma, although in many series it appears to be decreasing; initially at our institution, the incidence exceeded 30%, but is now less than 15%, and again is identical in patients with or without retroperitoneal lymphadenectomy, who have either pylorus preservation or a hemigastrectomy.

As the authors state, one reason for performing pylorus preservation is to eliminate the postgastrectomy syndromes. In their series, one patient after hemigastrectomy developed bile gastritis severe enough that subsequently a reoperation and Roux-en-Y gastrojejunostomy were required. A second patient apparently continues to have significant difficulty with control of the dumping syndrome. Whether these two long-term complications, one requiring reoperation, are justified by a savings of three days of hospitalization is questionable. Although peptic ulcer disease historically was feared to be a common complication after pylorus preservation, that has not proven to be the case. In the current series, peptic ulcers occurred more frequently in the pylorus-preserving patients, but it did not reach statistical significance.

Another argument in favor of pylorus preservation is that patients subsequently have a better nutritional status than when a hemigastrectomy is performed. This claim has been difficult to substantiate, and the authors’ findings in this study likewise show no difference between the two procedures. Nevertheless, that probably is not an adequate indication for a hemigastrectomy. I think most would feel that if a gastrectomy does not add anything to the procedure, there is no reason to perform it, whether or not there are nutritional benefits.

In summary, this paper presents a potpourri of patients with benign disease undergoing pancreaticoduodenectomy, some with pylorus preservation and the others without. The series reports an admirably low hospital mortality and acceptably low complication rate. Most will not be able to compare their series of patients with chronic pancreatitis to this one, because of the unusually low number of patients with alcohol as an etiology and the large number of patients with ampullary stenosis, pancreas divisum, or who were suspected preoperatively of having a neoplasm. Nevertheless, the outcomes are superb considering the patient populations, and the paper represents another outstanding contribution from an institution that is one of the leading pancreatic surgery centers in the country. The authors are to be congratulated on their excellent results.