In-bag manual versus uncontained power morcellation for laparoscopic myomectomy

Review question

Cochrane authors reviewed the effectiveness and safety of in-bag manual morcellation compared to uncontained power morcellation during laparoscopic myomectomy. The primary outcome of the review was a composite of intraoperative (during surgery) complications.

Background

Myomectomy is a surgical procedure to remove uterine fibroids — also called leiomyomas. These common, non-cancerous growths usually develop in the uterus during childbearing years, but they can occur at any age. In laparoscopic myomectomy, which is a minimally invasive procedure, the surgeon accesses and removes the fibroids through several small abdominal incisions.

Laparoscopic myomectomy is the gold standard for women with uterine leiomyomas, but it is difficult to remove large fibroids through the small incisions and tubes (laparoscopes). To overcome this challenge, surgeons developed a technique to break the large fibroids into smaller pieces (morcellation).

However, power morcellation (using a drill-like instrument to cut up the fibroids) inside the abdomen may lead to the scattering of the tissues. These tissues may be benign (such as fibroids or endometriosis), but they may also be tissues from an undiagnosed cancer. A strategy to optimise women's safety is to cut up larger fibroids with a scalpel or scissors, inside a bag.

Study Characteristics

We included two randomised controlled trials, which enrolled 176 premenopausal women undergoing laparoscopic myomectomy; they were randomised to receive either in-bag manual morcellation (87 women) or uncontained power morcellation (89 women). The literature was searched to 1 July 2019.

Key results

Neither study reported complications during or after surgery, including no diagnoses of leiomyosarcoma, for women in either group.

We are very uncertain whether in-bag morcellation reduces the total time of the operation, or improves the ease of morcellation. The evidence suggests that the morcellation operative time was slightly longer when the surgeon used in-bag morcellation. However, the quality of the evidence is very low and we cannot be certain of any of these results.

Quality of the evidence

The evidence was of very low quality. The main limitations were indirectness (both trials took place in high-income settings and countries, therefore, our findings are limited to this type of setting), and imprecision (both trials had small sample sizes and wide confidence intervals).

Authors' conclusions: 

There are limited data on the effectiveness and safety of in-bag morcellation at the time of laparoscopic myomectomy compared to uncontained power morcellation. We were unable to determine the effects of in-bag morcellation on intraoperative complications as no events were reported in either group. We are uncertain if in-bag morcellation improves total operative time or ease of morcellation compared to control. Regarding morcellation operative time, the quality of the evidence was also very low and we cannot be certain of the effect of in-bag morcellation compared to uncontained morcellation. No cases of postoperative diagnosis of leiomyosarcoma occurred in either group. We found only two trials comparing in-bag extracorporeal manual morcellation to intracorporeal uncontained power morcellation at the time of laparoscopic myomectomy. Both trials had morcellation operative time as primary outcome and were not powered for uncommon outcomes such as intraoperative complications, and postoperative diagnosis of leiomyosarcoma.

Large, well-planned and executed trials are needed.

Read the full abstract...
Background: 

Uterine leiomyomas, also referred to as myomas or fibroids, are benign tumours arising from the smooth muscle cells of the myometrium. They are the most common pelvic tumour in women. The estimated rate of leiomyosarcoma, found during surgery for presumed benign leiomyomas, is about 0.51 per 1000 procedures, or approximately 1 in 2000.

Treatment options for symptomatic uterine leiomyomas include medical, surgical, and radiologically-guided interventions. Laparoscopic myomectomy is the gold standard surgical approach for women who want offspring, or otherwise wish to retain their uterus. A limitation of laparoscopy is the inability to remove large specimens from the abdominal cavity through the laparoscope. To overcome this challenge, the morcellation approach was developed, during which larger specimens are broken into smaller pieces in order to remove them from the abdominal cavity via the port site. However, intracorporeal power morcellation may lead to scattering of benign tissues, with the risk of spreading leiomyoma or endometriosis. In cases of unsuspected malignancy, power morcellation can cause unintentional dissemination of malignant cells, and lead to a poorer prognosis by upstaging the occult cancer.

A strategy to optimise women's safety is to morcellate the specimens inside a bag. In-bag morcellation may avoid the dissemination of tissue fragments.

Objectives: 

To evaluate the effectiveness and safety of protected in-bag extracorporeal manual morcellation during laparoscopic myomectomy compared to intra-abdominal uncontained power morcellation.

Search strategy: 

On 1 July 2019, we searched; the Cochrane Gynaecology and Fertility Group Specialized Register of Controlled Trials, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, PubMed, Google Scholar, and two trials registers.

We reviewed the reference lists of all retrieved full-text articles, and contacted experts in the field for additional and ongoing trials.

Selection criteria: 

We included all randomised controlled trials comparing in-bag extracorporeal manual morcellation versus intracorporeal uncontained power morcellation during laparoscopic myomectomy in premenopausal women.

Data collection and analysis: 

We followed standard Cochrane methods.

Two review authors independently reviewed the eligibility of trials, extracted data, and evaluated the risk of bias. Data were checked for accuracy.

The summary measures were reported as risk ratios (RR) or mean differences (MD) with 95% confidence interval (CI).

The outcomes of interest were a composite of intraoperative and postoperative complications, operative times, ease of morcellation, length of hospital stay, postoperative pain, conversion to laparotomy, and postoperative diagnosis of leiomyosarcoma. Results for the five main outcomes follow.

Main results: 

We included two trials, enrolling 176 premenopausal women with fibroids, who underwent laparoscopic myomectomy.

The experimental group received in-bag manual morcellation, during which each enucleated myoma was placed into a specimen retrieval bag, and manually morcellated with scalpel or scissors. In the control group, intracorporeal uncontained power morcellation was used to reduce the size of the myomas.

No intraoperative complications, including accidental morcellation of the liver, conversion to laparotomy, endoscopic bag disruption, bowel injury, bleeding, accidental injury to any viscus or vessel, were reported in either group in either trial.

We found very low-quality evidence of inconclusive results for total operative time (MD 9.93 minutes, 95% CI -1.35 to 21.20; 2 studies, 176 participants; I² = 35%), and ease of morcellation (MD -0.73 points, 95% CI -1.64 to 0.18; 1 study, 104 participants). The morcellation operative time was a little longer for the in-bag manual morcellation group, however the quality of the evidence was very low (MD 2.59 minutes, 95% CI 0.45 to 4.72; 2 studies, 176 participants; I² = 0%). There were no postoperative diagnoses of leiomyosarcoma made in either group in either trial.

We are very uncertain of any of these results. We downgraded the quality of the evidence due to indirectness and imprecision, because of limited sites in high-income settings and countries, small sample sizes, wide confidence intervals, and few events.