according to a study published in Obstetrics & Gynecology.
U.S. Air Force photo by Staff Sgt. Ciara Gosier
The retrospective cohort study looked at data from 37,485 patients who underwent 43,751 gynecologic surgical procedures, including hysterectomy and myomectomy, at two tertiary care academic hospitals.
Overall, 96 patients (0.2%) were diagnosed with postoperative venous thromboembolism. However patients who underwent laparoscopic or vaginal surgery had a significant 78% and 93% lower risk of venous thromboembolism, respectively, than those who underwent laparotomy, even after adjusting for potential confounders such as age, cancer, race, pharmacologic thromboprophylaxis, and surgical time.
The incidence of postoperative thromboembolism was significantly higher among patients undergoing gynecologic surgery for cancer (1.1%). The incidence among those undergoing surgery for benign indications was only 0.2%, and the highest incidence was among patients with cancer who underwent laparotomy (2.2%).
“This study adds to data demonstrating that venous thromboembolism is rare in gynecologic surgery, particularly when a patient undergoes a minimally invasive procedure for benign indications,” wrote Dr. Elisa M. Jorgensen of Beth Israel Deaconess Medical Center, and her coauthors.
Among the 8,273 patients who underwent a hysterectomy, there were 55 cases of venous thromboembolism – representing an 0.7% incidence. However patients who underwent laparotomy had a 1% incidence of postoperative venous thromboembolism, while those who underwent laparoscopic hysterectomy had an 0.3% incidence and those who underwent vaginal hysterectomy had an 0.1% incidence.
Laparotomy was the most common mode of surgery for hysterectomy – accounting for 57% of operations – while 34% were laparoscopic and 9% were vaginal.
However, the authors noted that the use of laparoscopy increased and laparotomy declined over the 9 years of the study. In 2006, 12% of hysterectomies were laparoscopic, compared with 55% in 2015, while over that same period the percentage of laparotomies dropped from 74% to 41%, and the percentage of vaginal procedures declined from 14% to 4%.
U.S. Air Force photo by Staff Sgt. Ciara Gosier
“Because current practice guidelines do not account for mode of surgery, we find them to be insufficient for the modern gynecologic surgeon to counsel patients on their individual venous thromboembolism risk or to make ideal decisions regarding selection of thromboprophylaxis,” Dr. Jorgenson and her associates wrote.
Only 5 patients of the 2,851 who underwent myomectomy developed postoperative VTE – an overall incidence of 0.2% – and the authors said numbers were too small to analyze. Vaginal or hysteroscopic myomectomy was the most common surgical method, accounting for 62% of procedures, compared with 23% for laparotomies and 15% for laparoscopies.
More than 90% of patients who experienced postoperative thromboembolism had received some form of thromboprophylaxis before surgery, either mechanical, pharmacologic, or both. In comparison, only 55% of the group who didn’t experience thromboembolism had received thromboprophylaxis.
“The high rate of prophylaxis among patients who developed postoperative venous thromboembolism may reflect surgeons’ abilities to preoperatively identify patients at increased risk, guiding appropriate selection of thromboprophylaxis,” Dr. Jorgenson and her associates wrote.
Addressing the study’s limitations, the authors noted that they were not able to capture data on patients’ body mass index and also were unable to account for patients who might have been diagnosed and treated for postoperative VTE at other hospitals.
No conflicts of interest were declared.
SOURCE: Jorgensen EM et al. Obstet Gynecol. 2018 Nov;132:1275-84.