Over the last 3 decades, abundant evidence has demonstrated the association between surgical volume and outcomes. Patients operated on by high-volume surgeons and at high-volume hospitals have superior outcomes.1,2 This relationship has provided a framework for a number of public health policies to try to align patients with appropriate providers and centers to optimize perioperative outcomes. In this article, we examine the volume-outcomes paradigm for gynecologic surgery and explore how this relationship is influencing patterns of care and policy.
Surgical volume in gynecology
The association between both hospital and surgeon volume and outcomes has been explored across a number of gynecologic procedures.3 A meta-analysis that included 741,000 patients found that low-volume surgeons had an increased rate of complications overall, a higher rate of intraoperative complications, and a higher rate of postoperative complications compared with high-volume surgeons. While there was no association between volume and mortality overall, when limited to gynecologic oncology studies, low surgeon volume was associated with increased perioperative mortality.3
While these studies demonstrated a statistically significant association between surgeon volume and perioperative outcomes, the magnitude of the effect is modest compared with other higher-risk procedures associated with greater perioperative morbidity. For example, in a large study that examined oncologic and cardiovascular surgery, perioperative mortality in patients who underwent pancreatic resection was reduced from 15% for low-volume surgeons to 5% for high-volume surgeons.1 By contrast, for gynecologic surgery, complications occurred in 97 per 1,000 patients operated on by high-volume surgeons compared with between 114 and 137 per 1,000 for low-volume surgeons. Thus, to avoid 1 in-hospital complication, 30 surgeries performed by low-volume surgeons would need to be moved to high-volume surgeons. For intraoperative complications, 38 patients would need to be moved from low- to high-volume surgeons to prevent 1 such complication.3 In addition to morbidity and mortality, higher surgeon volume is associated with greater use of minimally invasive surgery, a lower likelihood of conversion to laparotomy, and lower costs.3
Similarly, hospital volume also has been associated with outcomes for gynecologic surgery.4 In a report of patients who underwent laparoscopic hysterectomy, the authors found that the complication rate was 18% lower for patients at high- versus low-volume hospitals. In addition, cost was lower at the high-volume centers.4 Like surgeon volume, the magnitude of the differential in outcomes between high- and low-volume hospitals is often modest.4
While most studies have focused on short-term outcomes, surgical volume appears also to be associated with longer-term outcomes. For gynecologic cancer, studies have demonstrated an association between hospital volume and survival for ovarian and cervical cancer.5-7 A large report of centers across the United States found that the 5-year survival rate increased from 39% for patients treated at low-volume centers to 51% at the highest-volume hospitals.5 In urogynecology, surgeon volume has been associated with midurethral sling revision. One study noted that after an individual surgeon performed 50 procedures a year, each additional case was associated with a decline in the rate of sling revision.8 One could argue that these longer-term end points may be the measures that matter most to patients.
Although the magnitude of the association between surgical volume and outcomes in gynecology appears to be relatively modest, outcomes for very-low-volume (VLV) surgeons are substantially worse. An analysis of more than 430,000 patients who underwent hysterectomy compared outcomes between VLV surgeons (characterized as surgeons who performed only 1 hysterectomy in the prior year) and other gynecologic surgeons. The overall complication rate was 32% in VLV surgeons compared with 10% among other surgeons, while the perioperative mortality rate was 2.5% versus 0.2% in the 2 groups, respectively. Likely reflecting changing practice patterns in gynecology, a sizable number of surgeons were classified as VLV physicians.9
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