Prophylactic Pancreatectomies Carry Prohibitive Mortality at Low-Volume Centers: A California Cancer Registry Study

Centralization of Pancreaticoduodenectomy: A Systematic Review and Spline Regression Analysis to Recommend Minimum Volume for a Specialist Pancreas Service

OBJECTIVE

Through a systematic review and spline curve analysis, to better define the minimum volume threshold for hospitals to perform (pancreaticoduodenectomy) and the high-volume center.

BACKGROUND

The pancreaticoduodenectomy (PD) is a resource-intensive procedure, with high morbidity and long hospital stays resulting in centralization towards high-volume hospitals; the published definition of high volume remains variable.

MATERIALS AND METHODS

Following a systematic review of studies comparing PD outcomes across volume groups, semiparametric regression modeling of morbidity (%), mortality (%), length of stay (days), lymph node harvest (number of nodes), and cost ($USD) as continuous variables were performed and fitted as a smoothed function of splines. If this showed a nonlinear association, then a "zero-crossing" technique was used, which produced "first and second derivatives" to identify volume thresholds.

RESULTS

Our analysis of 33 cohort studies (198,377 patients) showed 55 PDs/year and 43 PDs/year were the threshold value required to achieve the lowest morbidity and highest lymph node harvest, with model estimated df 5.154 ( P <0.001) and 8.254 ( P <0.001), respectively. The threshold value for mortality was ~45 PDs/year (model 9.219 ( P <0.001)), with the lowest mortality value (the optimum value) at ~70 PDs/year (ie, a high-volume center). No significant association was observed for cost ( edf =2, P =0.989) and length of stay ( edf =2.04, P =0.099).

CONCLUSIONS

There is a significant benefit from the centralization of PD, with 55 PDs/year and 43 PDs/year as the threshold value required to achieve the lowest morbidity and highest lymph node harvest, respectively. To achieve mortality benefit, the minimum procedure threshold is 45 PDs/year, with the lowest and optimum mortality value (ie, a high-volume center) at approximately 70 PDs/year.

Innovation in the Surgical Management of Pancreatic Cystic Neoplasms: Same Operations, Narrower Indications, and an Individualized Approach to Decision-Making

Historically, the management of pancreatic cystic neoplasms (PCN) has been operative. Early intervention for premalignant lesions, including intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN), offers an opportunity to prevent pancreatic cancer-with potential decrement to patients' short-term and long-term health. The operations performed have remained fundamentally the same, with most patients undergoing pancreatoduodenectomy or distal pancreatectomy using oncologic principles. The role of parenchymal-sparing resection and total pancreatectomy remains controversial. We review innovations in the surgical management of PCN, focusing on the evolution of evidence-based guidelines, short-term and long-term outcomes, and individualized risk-benefit assessment.

Mortality factors in pancreatic surgery: A systematic review. How important is the hospital volume?

BACKGROUND

How the extent of confounding adjustment impact (hospital) volume-outcome relationships in published studies on pancreatic cancer surgery is unknown.

METHODS

A systematic literature search was conducted for studies that investigated the relationship between volume and outcome using a risk adjustment procedure by querying the following databases: PubMed, Cochrane Central Register of Controlled Trials, Livivo, Medline and the International Clinical Trials Registry Platform (last query: 2020/09/16). Importance of risk-adjusting covariates were assessed by effect size (odds ratio, OR) and statistical significance. The impact of covariate adjustment on hospital (or surgeon) volume effects was analyzed by regression and meta-regression models.

RESULTS

We identified 87 studies (75 based on administrative data) with nearly 1 million patients undergoing pancreatic surgery that included in total 71 covariates for risk adjustment. Of these, 33 (47%) had statistically significant effects on short-term mortality and 23 (32%) did not, while for 15 (21%) factors neither effect size nor statistical significance were reported. The most important covariates for short term mortality were patient-specific factors. Concerning the covariates, single comorbidities (OR: 4.6, 95% CI: 3.3 to 6.3) had the strongest impact on mortality followed by hospital volume (OR: 2.9, 95% CI: 2.5 to 3.3) and the procedure (OR: 2.2, 95% CI: 1.9 to 2.5). Among the single comorbidities, coagulopathy (OR: 4.5, 95% CI: 2.8 to 7.2) and dementia (OR: 4.2, 95% CI: 2.2 to 8.0) had the strongest influence on mortality. The regression analysis showed a significant decrease hospital volume effect with an increasing number of covariates considered (OR: 0.06, 95% CI: 0.10 to -0.03, P < 0.001), while such a relationship was not observed for surgeon volume (P = 0.35).

CONCLUSIONS

This analysis demonstrated a significant inverse relationship between the extent of risk adjustment and the volume effect, suggesting the presence of unmeasured confounding and overestimation of volume effects. However, the conclusions are limited in that only the number of included covariates was considered, but not the effect size of the non-included covariates.