A new study published in Neurosurgery finds that patients who undergo a neurosurgical procedure with surgical start times between 9 pm and 7 am are at an increased risk of developing complications compared to patients with a surgical start time earlier in the day.


Neurosurgical procedures are necessary at all times of day. Previous studies have documented the relationship between surgical and medical management of diseases at night leading to worse outcome and it has particularly been exemplified in those undergoing: coronary angioplasty, orthopedic surgery, transplant surgery, colorectal surgery, and cardiac arrest patients. Other surgical specialties have examined the effect of surgical start time on morbidity and mortality; however, a similar study has not been performed for neurosurgical procedures.

Researchers here analyzed all patients undergoing neurological surgery between 2007 and 2014 in the University of Michigan Health System. This study included 15,807 patients. 785 complications were identified through the self-reported morbidity and mortality reports created by faculty and resident neurosurgeons.

The study showed that the odds of a complication were increased by more than 50% for procedures with start times between 9 pm and 7 am. When accounting for the length of the surgery, the odds of a complication were even greater for later time periods. The only statistically significant factor that predicted severity of the complication was if the operation was an emergency compared to an elective surgery.

The researchers believe that it is of the utmost importance to understand whether surgical start time might be related to neurosurgical procedural complications. Other surgical specialties have studied the negative relationship between late surgical start times and clinical outcome. The goal with this retrospective cohort study was to understand the relationship of surgical start time to the development of neurosurgical morbidity and mortality.

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