Distal Pancreatectomy: Indications and Outcomes in 235 Patients

Discussion

Dr. Andrew L. Warshaw (Boston, Massachusetts): This is, as Dr. Lillemoe said, an experience of 235 patients over 14 years—roughly 17 per year on average but most recently, 30 to 40 per year, reflecting the increasing volume of pancreatic surgery which is attracted to this premier institution. It clearly demonstrates that distal pancreatectomy can be done with very low mortality, the lowest reported as far as I know, and acceptable morbidity. As any good study should, it is a door-opener by stimulating many more questions, which I would like to ask the authors.

The 14-year time span will allow longitudinal observations, not only of the case members but evolution of case finding and case selection. How much has the common use of imaging tests increased the discovery of asymptomatic lesions such as cyst adenomas? Or decreased the fruitless attempted resection of carcinomas which are local, extensive, or metastatic?

Your length of stay averaged 15 days with a median of 10, almost equal to the length of stay which you have reported for Whipple operations. But what is it down to now? I suspect it is considerably lower in recent years.

There were 9 significant intraabdominal hemorrhages and 14 patients required early reexploration. Are these complications on the decline with modern technique and can they be prevented?

One fourth of your patients were resected for chronic pancreatitis—a small absolute number, all things considered. Does this reflect your disappointment with the success rate in treating pain in this disease with distal pancreatectomy, as we found in the absence of localized pathology such as a pseudocyst in the tail?

Twenty-five percent had a cystic neoplasm, but only 3% were cystadenocarcinomas. Since mucinous cystadenocarcinoma is more prevalent than the benign or borderline mucinous cystic neoplasms and 70% of mucinous cystadenocarcinomas are in fact resectable in most series, including ours, does this indicate that most of your cystic neoplasms were serous cystadenomas which did not become malignant? Or might your pathologists be less likely than ours to call a borderline mucinous cystic neoplasm cancer?

Eighteen percent of your patients had a ductal adenocarcinoma. This is in fact higher than I would have expected, since resectability of these lesions in general is so low. What is the denominator for these patients who are somewhere about 48 patients? What’s the denominator for that 48? Is your resection rate higher than the 5% to 15% reported by other institutions? Or do you do an extended dissection such as you are advocating for the Whipple operation? Or are you willing to leave gross tumor behind for a palliative excision?

You show that splenic preservation does not add risk, but does it provide substantial benefit in the adult? How do you balance such benefit against potential compromise of a cancer operation?

Finally, what are your indications for lesser procedures, either enucleation of smaller tumors or middle segment resection with Roux-en-Y reconstruction for greater preservation of pancreatic tissue?

While only 8% of your patients developed new insulin-dependent diabetes, surely more of them became diet-controlled diabetics or required oral agents, and, certainly, more of them will become insulin-dependent over time.

We accept enucleation of small islet cell tumors but worry about enucleation of the mucinous cystic neoplasms, especially since their malignancy may be and remain uncertain at the operating table.

We have now done 20 middle segment reductions and found them safe and suitable for selective lesions and for the purpose of preserving pancreatic tissue.

The size and quality of the Hopkins experience qualifies this as a benchmark report for perioperative outcomes.

Dr. William H. Nealon (Galveston, Texas): In the current report, the outcomes of 235 patients who have undergone distal pancreatectomy from 1984 through 1997, only 45 of which were performed prior to 1990 and thus, 190 of which have been performed since that date, are considered.

The authors describe the same sort of superb operative outcomes that we have all come to expect from this center with a mortality below 1%.

The fascinating mix of diagnoses managed by the procedure is consistent with the experiences of other major centers and is dominated by chronic pancreatitis and benign and malignant neoplasms, primarily cystic.

I have four questions:

First, in view of the fact that the largest percentage of patients underwent operation for chronic pancreatitis, what was the indication for this operation in that subset?

Since pseudocysts were listed as a separate entity for indication for operation, I presume these represent patients who were thought to have primarily disease in the body and tail of the pancreas. I wonder if you have any information—Dr. Warshaw already asked about the success rate for pain relief–but if you have any information on the degree of disease in the head of the gland in this subset of patients.

Second, you list diabetes as the most common complication with this operation. I wonder if there is any correlation between that outcome after operation and the diagnosis of chronic pancreatitis?

I also will mention that I have some concern when a report like this includes a morbidity rate of 30%, when this specific complication of glucose intolerance is included as a primary source of complication. Isn’t glucose intolerance quite predictable when the body and the tail of the pancreas are known to be anatomically where the majority of beta cells reside? And isn’t some element of glucose intolerance, therefore, predictable and possibly represent something you might term as a predictable outcome as opposed to an actual complication?

Third, I wonder if you have looked closely at your patients who have had massive hemorrhage. Although it’s a small number, was the management of the splenic artery or vein different in any way in that subset? Were any of those patients the ones that were managed by a stapling device across the body of the pancreas?

And my fourth question similarly relates to the complication of fistula formation: was any of the smaller subset of patients managed in a different fashion for the divided end of the pancreas, those that were managed by some of the alternative methods, particularly the placement of the stapling device?

Dr. James A. O’Neill, Jr. (Nashville, Tennessee): Since you included children in your report, it raises a question as to whether you and your colleagues make any effort toward splenic preservation in that regard.

I might share this experience with you. We recently reported 51 patients with various endocrine disorders that had varying degrees of what one might call distal or extended distal pancreatectomy. Now this is from a group of 84 patients that had various forms of distal pancreatectomy. And in the childhood age group, the entities are ordinarily various neuroendocrine disorders, including adenomas and diffuse islet cell dysplasia, trauma, usually with pancreatic pseudocysts associated, and chronic familial forms of pancreatitis. And in this group of 84 patients, there were 6 patients who had splenectomy performed. All of these patients had, at some time during their course, prophylactic therapy. It is of interest that in the follow-up of those patients—and these span about 25 years—there were two deaths due to postsplenectomy sepsis at 2 and 5 years following operation.

It certainly is the case that our results were similar to yours in terms of a very low fistula rate. There was no mortality, operative mortality, in this group of patients. So distal splenectomy, at least for benign disorders, is a relatively safe operation. But the long-term outlook relative to splenectomy and postsplenectomy sepsis, certainly in the childhood age group and in infancy, there is no argument about that. The risk in adults is less, but it isn’t zero. And, therefore, the question is whether with long-term follow-up you might see more problems with postsplenectomy sepsis.

And the question: Other than for malignant disease, should efforts be made to preserve the spleen? We will continue to do so in the age group that we deal with. I would be interested in your views of the young adult.

Dr. Keith D. Lillemoe (Closing Discussion): I’d like to thank the discussants for their comments. Dr. Warshaw, I really do agree with you that the new technology has brought forth a lot of previously asymptomatic benign cystadenomas of the pancreas that we have been referred probably because of our increasing experience with pancreatic surgery. Other new technology which has been helpful—we generally perform diagnostic laparoscopy in people with suspected adenocarcinoma of the body and tail of the pancreas in order to stage those patients to rule out peritoneal or liver metastasis, feeling that most of these patients have nothing to gain from a laparotomy in terms of palliation.

Both Dr. Warshaw and Dr. Nealon asked about the intraoperative hemorrhage. We really can’t quantitate the operative techniques very well. You can’t read between the lines of most operative notes. Certainly portal hypertension, occlusion of the splenic vein by cancer is a factor that may very well have contributed, or a benign inflammatory condition could very well have contributed, to the portal hypertension in these cases.

We, too, do not consider distal pancreatectomy a primary operation for most patients with chronic pancreatitis. We feel, as do most, that the heart of chronic pancreatitis begins in the head of the pancreas and, particularly in later years, where our increasing experience with pancreaticoduodenectomy has gone after this as being the sole problem with chronic pancreatitis. Most of our indications for distal pancreatectomy have involved an isolated distal stricture in the body or tail of the gland that has been seen on ERCP, which also raises the potential for a malignancy at that point.

Dr. Nealon asked about our outcome. We are concurrently evaluating a number of surgical options for chronic pancreatitis as part of a separate investigation and, therefore, we do not have those results to report today.

Andy, we do not know our absolute denominator for pancreatic cancer of the body and tail. Clearly, this number is small compared to that. Both your group, the group at Mayo, the group at Memorial Sloan-Kettering, and we previously have reported that these cases are frequently unresectable, both at the time that they present with simply CT scans as well as with our staging. I don’t have that number, nor do I have the follow-up in terms of the survival of those patients.

We certainly do not attempt a palliative resection for pancreatic cancer of the body and tail, although I would have to acknowledge that in some cases there was a positive margin, usually at the celiac axis.

The splenectomy is always performed when cancer is suspected, so we do not compromise our cancer operation with splenic preservation.

We have an interest in the lesser operations. Last year at this meeting, Dr. Pitt reported our limited experience with approximately 14 patients with enucleation of serous lesions. Many of these were located in the head of the pancreas—trying to avoid a Whipple in these otherwise normal glands. Whereas, if we are in the body and tail, we will more likely than not go with a distal pancreatectomy.

We have no experience with your midsegment pancreatectomy. I certainly have seen your work and think it is an excellent option in those selected patients with tumors that fall into that area.

We acknowledge, for both Bill and Dr. Warshaw, that a longer follow-up is necessary to determine the absolute incidence of diabetes mellitus. And, Bill, we struggled whether to consider this a complication or just the extent of the disease process. Certainly, the patients with chronic pancreatitis had a greater incidence of postoperative diabetes.

Dr. Nealon, in addition to the questions I have tried to answer in conjunction with Dr. Warshaw’s, asked if there was any correlation with fistulas and the use of the stapling device, and we do not have that analysis.

Dr. O’Neill, we are certainly interested in splenic preservation in all our young children. We are aware that postsplenectomy sepsis is not isolated only to children. As I said, certainly if there is the specter of malignant disease, either for a big cystic neoplasm or what is suspected to be an adenocarcinoma, we do not consider splenic preservation. But in many of the other cases, we will do that. Of course, a lot of times for malignant and sometimes benign disease with chronic pancreatitis, we will run into cases of splenic vein thrombosis, and we will plan to take the vein routinely in that situation.