What is the relationship between hospital caseload and outcome in incisional hernia repair?-A registry-based analysis of 55,584 patients.

Introduction: There is an ongoing controversal debate about whether the hospital volume (hospital case load) or the surgeon volume has a greater influence on outcome. The implications of high surgeon volume for the outcome have been demonstrated for ventral and incisional hernia repair. This analysis of data from the Herniamed Registry now aims to assess the relationship between hospital volume/hospital case load and outcome in incisional hernia repair.

Methods: To calculate the caseload all repairs carried out in the centers and which met the inclusion criteria were included. The annualized number (based on the time difference between the first and last entry for the respective center) of repairs per center was used for the following categories: < = 20 procedures per year, > 20 - < = 40 procedures per year, > 40 procedures per year. The association of confirmatory defined patient- and procedure-related characteristics to the outcome parameters (general, intraoperative and postoperative surgical complications, complication-related reoperations as well as recurrences, pain at rest, pain on exertion, and chronic pain requiring treatment on 1-year follow-up) was analyzed using logistic regression models.

Results: Following patient selection, 55,584 patients were included in analysis of the relation of the hospital volume as well as of other potential confounders to the outcome parameters. In the caseload group with ≤ 20 incisional hernias per year, the mean number of surgeons was 6.8, whereas in the caseload group > 20 - ≤ 40 per year the mean number was 12.9 surgeons and in the caseload group > 40 incisional hernias per year, the mean number was 23.7 surgeons. The multivariable analysis of the data from the Herniamed Registry demonstrates that a lower case load is associated with a higher risk of postoperative surgical complications and recurrences, but with a lower risk of pain at rest, pain on exertion and chronic pain requiring treatment.

Conclusion: In summary, this analysis of data from the Herniamed Registry demonstrates that a relatively large number of surgeons are involved in the repair of incisional hernias, regardless of the hospital caseload. High hospital volume comes with a price of more surgeons participating resulting in higher postoperative surgical complication and recurrence risk. Low-volume centers seem to manage less severe cases, whereas high-volume centers appear to act as referral centers, treating more complex cases, which might reflect influence of unobserved confounders.