International Hepato-Pancreato-Biliary Association
HPB Blog - May 2019
HPB investigator questions from around the world
As I embark on my first blog as an Associate Editor for the journal after several months of serving in this role, I am incredibly impressed by the caliber and diversity of research submitted to the journal. The journal has strengthened in impact over recent years, and continues to expand in terms of scope of topic as well as location of authors, reflecting well the global HPB community of the IHPBA and its regional associations. In the May issue of HPB, you will note papers by authors from North America, Europe, Asia, and Australia. Both the research methodologies and the questions investigated are diverse as well.
Two of the papers emanate from the AHPBA’s research committee, focusing on the Delphi process. Mansour et al. reported that in the absence of level 1 data, expert consensus opinion may be useful to guide management and decision-making, for the management of well-differentiated, asymptomatic pancreatic neuroendocrine tumors (PNET). An expert panel reached consensus regarding recommendations against resection for these tumors smaller than 1 cm, for resection for those tumors larger than 2 cm, for lymph node dissection in the setting of radiographically concerning lymph nodes and splenectomy for distal lesions, for enucleation or central pancreatectomy when technically appropriate. Maker et al. then surveyed conference attendees regarding the influence of conference attendance on their opinions about management of PNETs. Conference attendance did impact opinions relating to need for biopsy, threshold for resection, and the role of lymph node dissection and hence, the authors concluded this format may be helpful for the dissemination of knowledge and to impact practice patterns.
Two papers investigated the roles of biomarkers – one relating to PNETs and the other for pancreatic cancer. Pulvirenti and colleagues studied the role of Chromogranin A as a biomarker for well-differentiated PNETs, and reported that its low sensitivity limited its role as a diagnostic marker. However, it has some prognostic value given its association with disease-free survival. Laurent et al found that Ca19-9 decline of >15% in response to chemotherapy for locally advanced or metastatic pancreatic adenocarcinoma was associated with improved progression-free and overall survival. This finding may guide decision-making and discussions of prognosis in this patient group.
There are three papers focusing on unique technical aspects of HPB surgery, from liver resection, to transplant, to pancreatectomy. Lan et al evaluated the difference in impact between intermittent Pringle and continuous hemi-hepatic vascular inflow occlusion (CVHIO) on outcomes after laparoscopic liver resection for HCC for patients with and without cirrhosis. Cirrhotic patients undergoing resection with intermittent Pringle had significantly decreased operative time and blood loss compared to those in the CVHIO group. These surgeons also describe their technique for laparoscopic Pringle as well as for anatomic or extra-Glissonian CVHIO. Tan and colleagues presented a review of their center’s algorithm for choice of middle hepatic vein positive or negative living donor liver transplants, concluding that MHV+ cases were longer for both donors and recipients, but without any difference in mortality; hence, the decision whether or not to use the MHV should be based on donor and recipient characteristics. The third technique paper by Oba et al is a prospective, exploratory investigation of the use of ICG angiography to evaluate flow across vascular anastomoses and gastric tissue perfusion after distal pancreatectomy with celiac axis resection and left gastric artery reconstruction. Poor flow was associated with delayed gastric emptying if not mitigated by redoing the anastomosis.
Liver function was the focus of three papers this month. Dasari et al developed and validated a risk score for the development of post-hepatectomy liver failure, predictive of increased mortality and length of stay, that outperformed MELD in predictive capacity. Tomassini et al assessed the influence of liver hemodynamics on future liver remnant regeneration and function with ALPPS, finding that volume overestimates liver function and that the regenerative process after ALPPS correlates with an increase in portal perfusion. Rassam and colleagues investigated the quantification of liver function with HB scintigraphy and/or transient elastography. They concluded that these assessments may be useful for risk stratification given the ability to assess liver fibrosis in a non-invasive manner with transient elastography and to evaluate global and regional liver function with the scintigraphy.
The two papers on IPMN management comprise efforts to address ongoing questions about how to best decide which patients warrant resection as well as outcomes for those IPMNs with an invasive component. Simpson et al identify main pancreatic duct diameter of 10mm or greater as the clinical criterion that improves the accuracy of the integrated molecular pathology risk score, allowing better stratification of patients to surgery or surveillance. Marchegiani and colleagues describe clinical outcomes for patients with invasive IPMN, noting that adjuvant therapy improves disease-specific survival in patients with N1 disease and tubular carcinomas.
Cost and value constitute important metrics for surgical care. Jajja et al evaluate cost savings and outcomes associated with standardization of technique for laparoscopic right hepatectomy, showing significant cost savings compared to both open right hepatectomy as well as to pre-standardization laparoscopic right hepatectomy. The primary intraoperative cost difference was in stapler costs. After standardization, the minimally invasive group had superior outcomes and cost savings, when including the postoperative costs as well as intraoperative costs. High volume anesthesiologists yield cost savings and improved efficiencies of care in patients undergoing pancreatectomy, as demonstrated by Uppal et al. This benefit was multifactorial as the high volume anesthesiologists may have had more complex cases, given they had longer operative times and higher ICU usage, but still overall decreased cost and equivalent quality of care, independent of surgeon experience. Cost benefits were also purported to be associated with adherence to surveillance guidelines for gallbladder polyps in the UK. Patel and colleagues report that with an annual detection rate of 12 pre-malignant or malignant gallbladder polyps per 1000 polyps surveyed, guideline adherence would save money. Overall compliance with recommendations is poor, at just 32.8%,
Lastly, remaining ever-intriguing for HPB surgeons, is the effort to predict and mitigate pancreatic fistula. Nahm et al find that the density of acinar cells on pathology, as well as the acinar density score on CT correlates with pancreatic fistula. Consistent with known risk and protective factors, the higher acinar density is associated with more normal pancreas, hence softer and more at risk for fistula. The authors propose that the CT score may be useful for assessing risk for fistula in the preoperative setting.
This month’s issue of HPB provides insight into surgeon attitudes, guidelines, prognostication, and high value care. I hope you enjoy it!