Prevention and Management of Complications of Pancreatic Surgery

Postpancreatectomy Hemorrhage

Hemorrhage associated with pancreatic resection (PPH) occurs in up to 8% of cases but may account for 11% to 38% of mortality. Because of the potential consequences of this problem, a consensus definition was developed by the International Study Group of Pancreatic Surgery (ISGPS) in 2007 and is seen in Table 105.2 . This definition was validated and has been found to correlate well with duration of hospital stay, morbidity, and mortality. It may occur intraoperatively, early in the postoperative period, or late (more than 24 hours postoperatively). Intraoperative hemorrhage may be more likely to occur in the event of aberrant vasculature particularly when not preoperatively identified. Fig. 105.1 demonstrates normal peripancreatic vasculature, as seen on computed tomography (CT) angiography. The common variations include a replaced right hepatic artery (11% to 21%), replaced left hepatic artery (4% to 10%), accessory right or left hepatic artery (<1% to 8%), and celiac artery stenosis (2% to 8%).

Intraoperative vascular complications are known to adversely affect ultimate outcome, including in-hospital mortality and survival rate; thus efforts to delineate vasculature preoperatively by means of a pancreatic protocol CT including arterial, venous, and portal venous phases should allow the surgeon to be better prepared intraoperatively and limit the occurrence of intraoperative hemorrhage related to an unexpected encounter with abnormal vascular anatomy. These efforts should continue intraoperatively by inspection and palpation of the operative field to further define the vascular anatomy. For example, a replaced right hepatic artery may be appreciated by palpation of a pulse posterior and lateral to the bile duct and portal vein. Intraoperative hemorrhage may also occur in the setting of tumor infiltration that involves the relevant vasculature.

To obtain intraoperative control of hemorrhage, direct pressure should be applied initially to allow for mobilization of appropriate anesthetic and surgical resources, such as blood products, vascular sutures, and clamps, and appropriate surgical assistance. Aberrant vasculature, such as a replaced right hepatic artery, may need to be reconstructed or anastomosed to an alternate vessel to preserve hepatic arterial blood flow. Doppler ultrasonography may be useful to determine whether there is already alternate arterial flow. Venous injuries may be able to be addressed with venorrhaphy or with patch venoplasty. In exsanguinating, uncontrolled hemorrhage, portal vein ligation has been described, with a potential for survival, when accompanied by a “second-look” laparotomy in 24 hours to evaluate for signs of ischemia. A more recent paper reports on a small series of patients undergoing damage control laparotomy (DCL) for pancreatic surgery, primarily for portal vein injury, with the goal of allowing intensive care unit (ICU) resuscitation to reverse the accompanying hypothermia, acidosis, and coagulopathy. They describe initial venous compression to allow for identification/visualization of the site of injury, as well as for preparation of the surgical and anesthetic teams. Useful maneuvers for compression included the Kocher maneuver and sponge sticks. The pancreas was then divided and the specimen quickly extirpated when possible. Other techniques used to shorten operating time included external drainage, packing, stapled bowel closure, and rapid abdominal closure. The authors emphasize that there was significant resource use but no mortality. Other risk factors for PPH have been identified including age, pancreatic fistula, pancreatoduodenectomy, and the nutritional risk index (NRI).

Management of early and late PPH is addressed by the ISGPS classification schema. Early PPH is most often a result of technical failure to achieve appropriate hemostasis at the index operation or else secondary to underlying coagulopathy. When significant and thought to be technical failure, prompt relaparotomy is mandated. PPH occurring later than the first postoperative day and up to several weeks postoperatively is often a result of other postoperative complications, such as fistula, anastomotic ulceration, or pseudoaneurysm. PPH may represent bleeding from intraluminal or extraluminal sources: unsecured vessels, vessels with pseudoaneurysm, anastomotic suture lines or ulceration, resection cut surfaces, or hemobilia. Named vascular structures that may be the source of bleeding are the gastroduodenal, hepatic, or splenic artery, branches of the superior mesenteric artery, or the splenic vein stump. The classification system for PPH is described in Table 105.2 .

After PPH becomes apparent, evaluation must occur in a timely fashion and may include a variety of modalities depending on the hemodynamic status of the patient and apparent location of the bleeding (intraluminal or extraluminal): endoscopy, angiography, CT scan, or reoperation. Early extraluminal PPH requires reexploration. Intraluminal bleeding may manifest as extraluminal if there is associated anastomotic breakdown, and this may be amenable to angiographic intervention when involving the pancreaticojejunostomy. Bleeding from the gastrojejunostomy or duodenojejunostomy may first be excluded by endoscopy. Over time, conservative management has become more successful for late PPH but surgical intervention has continued to be the mainstay of treatment. Mortality in patients with late PPH is much higher than for the routine pancreatic resection, with rates of 16% to 27%, but is strongly associated with a bleed in the setting of a septic complication, such as pancreatic fistula. Patients present with septic complications and/or a sentinel bleed. Radiographic embolization has become a more successful modality, with up to 80% success, but is limited by the initially intermittent nature of the bleeding. Furthermore, key factors are the recognition of the sentinel bleed, the presence of pancreatic fistula, and a long gastroduodenal artery stump with radiopaque marker for an effective embolization. Reexploration is indicated when angiographic intervention is not technically feasible or successful or when the site is not visualized on angiography and the patient is hemodynamically unstable.

Pancreatic Fistula

POPF continues to be the nemesis of pancreatic resection. Occurring in up to 33% of cases, even in the setting of vast improvements in the safety and efficacy of pancreatic surgery overall as mentioned earlier, fistula rates have failed to decrease significantly. One must first recall the definition of fistula as “an abnormal communication from one epithelialized surface to another” compared with that of leakage , referring to “an abnormal escape of fluid through an orifice or opening.”

In addition, POPF occurs with the leakage of amylase-rich fluid from the transection margin of the gland and/or from the pancreatic-enteric anastomosis. Although many literature reports have been devoted to studying the diagnosis, management, and effect of POPF on patient outcome, comparison of these studies has been difficult because there was previously no uniform definition available. To better understand POPF, the ISGPF developed a classification scheme that is presented in Table 105.3 . POPF was defined as inclusive of all peripancreatic fluid collections, abscesses, leaks, or fistulas and diagnosed by virtue of drain amylase, output, imaging, and clinical picture (well versus septic). According to the classification scheme, grade A fistulas are biochemical only and not clinically relevant, whereas grades B and C fistulas are clinically relevant, requiring further evaluation and management, such as antibiotics, nutritional support, octreotide, and percutaneous drainage (grade B) or surgical exploration (grade C) in the setting of sepsis. Subsequent efforts to validate this classification scheme demonstrate that grade A fistulas comprise nearly half of all POPF yet have no apparent significant effect on outcome. However, grade B/C fistulas occur less often (40% and 11%, respectively) but are associated with higher resource use (ICU stay, nursing services post discharge, readmission), longer hospital stay, more complications, and, accordingly, increase in cost, grade for grade.