Post PD hemorrhage is a life-threatening post PD complication that requires prompt and appropriate treatment. It was reported to be one of the most common causes of death within 90 days of PD (15). The development of pancreatic fistula and related abdominal abscess formation are the main cause of erosion of major vessels and thus of delayed bleeding episodes (16, 17).
Negative angiography that provide no evidence of arterial extravasation or pseudoaneurysm poses a dilemma situation since it does not exclude the potential threat of subsequent massive bleeding (17). The false-negative angiographies could be due to the intermittent character of bleeding episodes, spastic contraction of blood and/or obstruction of vessels or blood clots (9, 10, 18). Therefore, empiric embolization of suspected vessels based on high clinical suspicion were supported (13). Similar recurrence rate (33.3%) in both groups was demonstrated in our study.
Conservative medical therapy carries a great risk of massive hemorrhage that even had no chance for repeated interventional procedure, while radical embolization may result in liver necrosis and intrahepatic abscess as well as to the necrosis of the extrahepatic bile duct or bilioenteric anastomosis (17). In the case of negative angiography, Bhavraj S. Khalsa et al performed either empiric embolization of the suspected site of bleeding, or vascular access was maintained in the common femoral artery during the following 24 hours in case of rebleed (12). Yekebas EF et al also chose to maintain vascular access for 24 hours when angiography failed to localize the bleeding site, and patients underwent re-angiography in case of recurrent bleeding within this period. The empiric embolization was successful in 4 among 5 patients with negative angiographic visualization based on the surgeons’ suspicion according to their study (13). However, 24 hours was obviously not long enough for hemorrhage recurrence observation in our study, since the recurrence time was all over 24 hours in the 5 cases with bleeding relapse (Table 1).
Determining empiric embolization is complex, and there are currently no acceptable criteria. General factors to consider when assessing suitability for embolization include hemorrhage severity, rebleeding risk, and whether the hepatic blood flow by an alternative route exist. The clinical decision of embolization was up to the hepatobiliary surgeon when negative result of angiography in our center, while the interventional radiologists determined the feasibility of the embolization. Hopefully, some early postoperative CT findings might play a critical role in predicting late post PD hemorrhage as that had been suggested by Han GJ et al (19).
Our data suggest that empiric embolization despite negative angiography result carries no obvious decreased recurrence rate, but its impact on survival warrant further study in larger samples. The two deaths in the empiric group might be partly explained by the high risk in emergency embolization due to hemodynamic coagulopathy when the patients had already experienced significant blood loss. The surgeons’ bias might exist when they decide empiric strategy for severe hemorrhage.
The recurrence rate in both groups in this series reminded us that embolization is still a temporizing measure in the presence of sepsis and pancreatic leak. Continued vascular damage can lead to recurrence of bleeding from the same site or other sites (5, 9). Surgery is the only option to control bleeding and manage the primary causes simultaneously (18). However, scheduled operation can be safe with reliable embolization performed. Empiric embolization seemed to bridge some patients for subsequent relaparotomy, with patients’ condition stable to endure the operation in this study.
The presented study has several limitations. Firstly, the sample size was small, without enough sample size for contrast study. Secondly, the retrospective nature of the study. Thirdly, subjective bias must exist since clinical decision was mainly made by the surgeons, based on their surgical experience and clinical suspicion. And obviously empiric embolization is preferred for patients with higher bleeding recurrence risk according to the surgeons’ judgement. Further cohort contrast study with larger sample size is warranted. Finally, CT findings of the negative cases were not included in this study.