BOSTON – In skilled hands, various vascular reconstructive methods used during pancreatic resections for adenocarcinoma result in early survival rates that are comparable to those in patients who undergo resection without vascular reconstruction, according to a retrospective review of cases.
This is important because up to 25% of cases in high-volume centers are borderline for resection using pancreaticoduodenectomy (Whipple procedure) because of vascular involvement. Resection is the only curative option for the disease, Dr. Michael D. Sgroi said at a meeting hosted by the Society for Vascular Surgery.
Of 270 Whipple procedures and total pancreatectomy procedures performed from January 2003 to February 2013 at a single institution, 147 were for pancreatic adenocarcinoma that involved the surrounding vasculature (T3 lesions); 60 of these involved vascular reconstructions (including 49 venous and 11 arterial reconstructions) and 87 were Whipple procedures without reconstruction, The venous reconstructions included 37 primary repairs, four reconstructions with CryoVein, three repairs using an autologous vein patch, three autologous saphenous reconstructions, and two portacaval shunts. The arterial reconstructions included seven hepatic artery reconstructions, and four were superior mesenteric artery reconstructions.
All were performed by the vascular surgery service, said Dr. Sgroi of the department of surgery, University of California, Irvine Medical Center, Orange.
Overall survival was greater than 18 months in the vascular reconstruction group, with no statistically significant difference seen between the various types of procedures or compared with the Whipple-only group. One perioperative death occurred (1.7%), and survival at 1 year for all reconstructions was 70.3% – a rate similar to the 72.6% survival among patients with T3 lesions who did not undergo vascular reconstruction.
Survival in the two groups remained similar at 3 years, but a survival advantage among those in the Whipple-only group emerged by year 4 and was statistically significant by year 5, Dr. Sgroi said.
No factors were found to be significantly associated with outcome, but there was a trend toward significance for positive lymph nodes and positive margins as predictors of survival. Positive margins were present in 22% of patients in the vascular reconstruction group, compared with only 11% of those in the Whipple-only group, he noted.
"Pancreatic adenocarcinoma is one of the most deadly neoplasms, with 1- and 5-year survival rates for all stages being 25% and 5%, respectively," he said, noting that resection is associated with high rates of morbidity.
Currently the only curative option for this disease is a margin-negative resection, but because most cases are not detected until they are in later stages, only about 20% of patients undergo resection, he said.
"As the morbidity and mortality rates have declined postoperatively following Whipple operations, the National Comprehensive Cancer Network guidelines have also changed to now consider borderline resectable or stage 2 tumors for resection. These are tumors that have portal vein, superior mesenteric vein, or confluence involvement as well as arterial involvement of less than 180 degrees of the common hepatic or right hepatic artery," he explained, adding that "in general, superior mesenteric artery or celiac access involvement is a contraindication to surgery, and these cases now account for about 25% of all Whipples performed in high-volume institutions."
The various approaches to reconstruction that can be performed have been used with acceptable patency rates and outcomes, and multiple single-institution reviews have demonstrated that both venous and arterial resections performed concomitantly with Whipple procedures have equivalent morbidity and mortality rates to Whipple performed without reconstruction.
"A flaw of these studies has always been that their sample size is small, diminishing the power of the study," Dr. Sgroi noted.
Further complicating the issue are two recent manuscripts demonstrating significantly increased morbidity and mortality with vascular reconstruction, while a review of the National Surgical Quality Improvement Program database showed that when vascular surgeons are involved, outcomes are comparable with and without reconstruction – with the exception of increased blood loss and time in the operating room with vascular reconstruction.
The findings of the current study support the latter finding.
Notably, with the advances in chemotherapy agents it is now protocol that all patients at the University of California, Irvine receive neoadjuvant chemotherapy, and survival was improved in those who received both vascular reconstruction and neoadjuvant chemotherapy, compared with those who received vascular reconstruction without neoadjuvant chemotherapy.
"We believe that experience matters with this operation and that there is a learning curve," he said.
An example involves the need for packed red blood cells. The average number of units of packed red blood cells given with each case declined over time, and now less than one unit is used per case, he noted.