DELIVERY AFTER MYOMECTOMY

Uterine fibroid is the commonest benign tumor of the uterus.  It can be associated with difficulty to conceive.  For those women who have uterine fibroid in pregnancy, it may cause pain due to degeneration, fetal malpresentation, or placenta previa. Most women with uterine fibroid may have undergone a myomectomy (surgical removal of the fibroid) prior to conception.  The scar from myomectomy surgery may be associated with the uterine wall weakness and increases the risk of uterine rupture.

How common is uterine rupture after a myomectomy?

Uterine rupture is an obstetrical emergency that can be catastrophic for the mother and fetus. Previous uterine surgery, including previous cesarean delivery or myomectomy, is an established risk factor, although the exact magnitude of the associated risk remains uncertain.

The consequences of uterine rupture affect both the mother and the fetus. Maternal consequences of uterine rupture include severe internal bleeding (hypovolaemic shock), genitourinary injury, potential need for hysterectomy, and maternal death. The fetal sequelae include fetal hypoxia and fetal or neonatal death. In 2003, Chauhan (2003) estimated that the overall rate of hysterectomy secondary to uterine rupture is 0.09% with a perinatal mortality rate of 0.04% and a maternal mortality rate of 0.02%.

 

The reported prevalence of uterine rupture following a Caesarean section is about 1%.  The frequency of uterine rupture is generally lower in developed countries compared undeveloped countries.  Meanwhile, the incidence of uterine rupture following myomectomy  is 0.79 %, which is comparable with that after cesarean section.

This risk is estimated to be lower than a classical Caesarean scar (incision on the muscular part of uterus).  The American College of Obstetricians and Gynecologists (ACOG) has cited a uterine rupture risk of 4%-9% for women with prior classical caesarean and a trial of vaginal delivery is contraindicated.

 

The current available evidence shows no significant difference between the incidences of a rupture during pregnancy following a laparoscopic (1.2 %) versus an open myomectomy (0.4 %).  The location, size of the fibroids and breach of the uterine cavity, surgical skills and technique (of suturing) also affect the likelihood of uterine rupture following previous myomectomy.

 

However, most studies on the safety of vaginal delivery after a myomectomy have several important limitations including non prospective, selection bias, under-reporting of iatrogenic complications and publication bias.  The under-estimated true risk of uterine rupture, a potentially life-threatening event is possibly contributed by more primary Caesarean section performed to avert medicolegal litigation.

 

Should women with myomectomy have trial of vaginal delivery?

 

The mode of delivery following myomectomy is controversial. Though the risk for uterine rupture is low (less than 1%) following a myomectomy, regardless of the technique used, the evidence is not robust.  It is clear that randomized studies are needed to study the effectiveness of laparoscopic myomectomy for the adverse outcome of uterine rupture before conclusive evidence can be used to present evidence-based recommendations for daily clinical practice.

 

This estimation of the incidence might be used for counseling women wishing to conceive after a myomectomy, but it should be done with utmost caution.

Some physicians will allow labor, as long as the uterine cavity has not been breached or less 50 percent of the uterine wall has been incised during myomectomy. However, ACOG currently recommends cesarean section following myomectomy be performed between 37 and 38 week to decrease the chance of the patient first going into labor with its risk of uterine rupture

Milton (2015) states that although there are limited data to support an elective Caesarean delivery, it should be offered to pregnant women who had myomectomies, in which large defects in the active segment of the uterus were created by removal of the fibroids. He feels that the total extent of the defect has a more significant impact on the risk of rupture compare to breach of the uterine cavity during the procedure.

There is currently insufficient evidence to determine the recommended mode of delivery following myomectomy. Some women are offered an elective Caesarean delivery by clinicians with the intention of reducing the risk of uterine rupture.

Conclusions

Uterine rupture during subsequent pregnancy seems to be a rare event.  Due to paucity of robust evidence and given the potentially devastating consequences of uterine rupture, a scheduled delivery at 38 weeks should be offered to women with myomectomy. However, this does not preclude a trial of vaginal delivery after an informed decision.

References

  1. ACOG Practice Bulletin, 2004.
  2. Bernardi TS et al., Archives of Gynecology & Obstetrics. 2014
  3. Chauhan SP et al., American J Obstet Gyne 2003.
  4. Milton, SH. In: eMedicine, ME Rivlin (ed). 2015

 

 

 

 

 

 

 

MRI GUIDED FOCUSED ULTRASOUND (MRIGFUS)- A NOVEL APPROACH TO THE TREATMENT OF UTERINE FIBROID?

Uterine fibroid is one of the commonest benign tumor amongst women.  It is present in 30%  of premenopausal women and is the main indication for hysterectomy.  Currently, there is no effective medical treatment available.  The uterine artery ablation has been offered as alternatives to surgical treatment (hysterectomy) but its clinical application is limited.

The MRI guided focused ultrasound is a minimally invasive fibroid treatment that uses a tightly focused ultrasound waves to deliver heat that instantaneously destroys fibroid tissue.  It is performed as an outpatient procedure with sedation.  The fibroid location is identified using T2-weighted MR imaging followed by a pretreatment planning and application of multiple therapeutic sonications to a temperature of at least 65 degree Celsius.  The heat generated basically ablates the fibroid tissue. The whole procedure takes about two to three hours.  The recovery time of about one to three days appears promising as a viable alternative to the current surgical option.

There are many reports of the experience with this treatment modality.  These reports were not from a high quality study design and occasionally sponsored by industry that are prone to bias and confounding.

There is only one randomized, placebo-controlled trial (PROMISe) to date, that assess the effectiveness of MRIgFUS therapy.  This is a high quality study and has a post treatment follow-up period of 2 years duration.  The result shows there is no diffence between MRIgFUS and placebo group, in terms of symptom improvement and quality of life at 4 to 12 weeks post procedure.  However, about a third (30%) of all women who had MRIgFUS therapy opted for hysterectomy by 2 years post treatment.

In summary, the MRIgFUS treatment for uterine seems promising and avoids the need for surgery.  Currently, the available results suggest its role as a temporary alternative treatment prior to the decision for hysterectomy, at best.

Reference

PROMISe trial (Pilot Randomized trial of MRIgFUS for symptomatic fibroid) trial. Fert Steril 2016

Alternative therapies in management of leiomyomas. Fert Steril 2014

Clinical improvement and shrinkage of uterine fibroids after thermal ablation by magnetic resonance-guided focused ultrasound surgery. Ultrasound Obstet Gynecol 2007.

Clinical outcomes of focused ultrasound surgery for the treatment of uterine fibroids.  Fert Steril 2006

 

 

 

FIBROIDS IN PREGNANCY

Uterine fibroids are the most common benign (noncancerous) gynecologic tumors, and are found in 1%–10% of women during pregnancy. Women with fibroids are more likely to have pregnancies with complications such as fetal malpresentation, preterm delivery, preterm premature rupture of membranes (PPROM), placenta previa, placental abruption, cesarean delivery, and severe postpartum hemorrhage. Babies born to women with fibroids may weigh less at birth than those born to women without fibroids.