Conference Coverage

Uterine volume, fibroid diameter predict robotic myomectomy duration



– It would be nice if surgeons could know beforehand how long robotic laparoscopic myomectomies will take, according to Peter Movilla, MD, a minimally invasive gynecologic surgery fellow at Newton (Mass.) Wellesley Hospital.

Dr. Peter Movilla, Newton (Mass.) Wellesley Hospital M. Alexander Otto/MDedge News

Dr. Peter Movilla

Best guesses are sometimes wrong, and it’s not uncommon for robotic cases to go longer than expected, especially when they have to be converted to an open approach.

Among other problems, going long backs up operating room (OR)scheduling and makes families impatient. Also, if it was known beforehand that a robotic case might take 5 hours, patients could be offered a quicker open procedure, especially if they are not good candidates for prolonged pneumoperitoneum.

After a case went past 6 hours at the University of California, San Francisco (UCSF), when Dr. Movilla was an ob.gyn. resident, he wanted to find a better way.

“I saw that we were not the best at guessing how long these surgeries were going to take, and thought maybe we could make prediction a little better by [incorporating] preoperative factors” in a structured way. “I wanted to create something that would give us an answer of how long it will take,” he said at a meeting sponsored by AAGL.

So he and his colleagues reviewed 126 robot-assisted laparoscopic myomectomies at UCSF. The mean operative time from skin incision to closure was 213 minutes, mean specimen weight 264.4 g, mean dominant fibroid diameter 8.5 cm, and mean number of fibroids removed 2.5. Four cases (3%) were converted to open laparotomy.

The team divided the cases by how long they took; 20% were under 3 hours, 70% took 3-5 hours; and 10% went over 5 hours. “Five hours is a long time to be in the OR,” especially when a case could have been done open, Dr. Movilla said.

Length of surgery correlated with 7 of the 21 preoperative factors considered on multivariate logistic regression. Cases tended to be longer in younger women and in women with diabetes, and when surgeons had less experience. There was a trend toward longer cases with higher body mass indices, but it was not statistically significant.

Having three or more fibroids on preoperative imaging and a larger number of fibroids over 3 cm were predictive of operations longer than 3 hours. However, the strongest predictors of long cases were uterine volume and the diameter of the largest fibroid, a mean of 532.4 cm3 and 8.8 cm, respectively, in cases over 5 hours. Posterior and intramural fibroids also increased operative time, but, again, the trends were not statistically significant.

The team put it all together in a risk calculator they tested against their subjects’ actual surgery times. The model tended to underestimate very short and very long cases at either end of the curve, but overall the fit was “not too bad,” and the more cases that are added to the model, the more accurate it will get, Dr. Movilla said.

There was no external funding for the work, and Dr. Movilla had no disclosures.

SOURCE: Movilla P et al. 2018 AAGL Global Congress, Abstract 69.

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