Patients with colorectal cancer have a greater chance of survival if they are operated in hospitals with a high case load because complications that can occur after surgery can be better managed there, according to researchers from the University Hospital of Würzburg in Bavaria, Germany. The paper, ‘Nationwide in‐hospital mortality rate following rectal resection for rectal cancer according to annual hospital volume in Germany’, published in BJS Open (a journal of the British Society of Surgery), shows there is a clear correlation between the number of operations performed per year in a hospital and the chance of survival.
"Two aspects are important for long-term survival after surgery: firstly, oncologically correct surgery and secondly, the right treatment if complications arise after surgery," said PD Dr Armin Wiegering, head of the Visceral Oncology Center at the University Hospital of Würzburg in Bavaria, Germany.
The researchers report hospitals that perform few operations on colorectal carcinomas (an average of six per year), the post-operative mortality rate is twice as high as in hospitals with large case numbers (an average of 50 per year). This difference is not due to the fact that complications occur more often in smaller hospitals because, according to Wiegering, this happens about equally often in all hospitals. Rather, the difference is that patients in small hospitals die more often from the complications.
"In large hospitals, on the other hand, there is a sufficient infrastructure to save patients in the event of postoperative complications," he explained.
In Germany, more than half of all patients with colon cancer are currently operated in hospitals that do not meet the minimum case numbers (50 per year) required by the German Cancer Society DKG. With more than 150 cases per year, the University Hospital of Würzburg is one of the hospitals with very high case numbers.
The study included all cases of colorectal carcinomas that were operated in hospitals in Germany between 2012 and 2015. That was a total of 64,349 patients. Across all hospitals, 3.9 percent of the patients died. In small hospitals the rate was 5.3 percent, in large clinics only 2.6 percent (p<0.001).
When the researchers looked at hospital volume as random effect, very high‐volume hospitals (53 interventions/year) had a risk‐adjusted odds ratio of 0.58 (95 per cent c.i. 0·47 to 0·73), vs baseline in‐house mortality rate in very low‐volume hospitals (6 interventions per year) (p<0.001). The overall postoperative complication rate was comparable between different volume quintiles, but failure to rescue decreased significantly with increasing caseload (15·6 per cent after pulmonary embolism in the highest volume quintile versus 38 per cent in the lowest quintile (p=0.010).
The most frequent surgical procedures were sphincter‐preserving anterior resection (15,380, and sphincter‐preserving low anterior resection (28,888).
They noted that sex, age category, co‐morbidity and emergency procedures were significantly associated with both in‐hospital mortality and hospital volume category and considered potential confounders and included in the regression analysis.
"This is the first time that we have been able to prove for Germany that there is a clear correlation between the number of patients operated per year and the success of the operation," said Wiegering. "We had not expected that the mortality rate in smaller clinics would be twice as high. It is therefore elementary to operate on patients in hospitals whose medical staff has sufficient experience."
Wiegering's team now plans to carry out similar analyses for stomach carcinomas, liver metastases and other tumour diseases.
“In view of the strong correlation found in this study between annual hospital caseload and postoperative morbidity and mortality following resection of rectal cancer, the introduction of highly specialised centres for rectal surgery is highly advocated to improve perioperative patient outcome,” the authors concluded. “Board certification for specialised cancer centres by the German Cancer Society would be a first step in improving the quality of treatment, but great economic, political and social effort is needed to achieve this.”
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