This video presents a stepwise approach to the hysteroscopic resection of a cesarean scar isthmocele. Two cases are presented to highlight the surgical steps and technical tips in successfully performing this procedure.
University of Toronto, Mount Sinai Hospital & Women’s College Hospital
Read More: Hysteroscopic Repair of Cesarean Scar Isthmocele
I am Ari Sanders, this is Ally Murji, and this is our video on cesarean scar isthmocele.
Cesarean scar isthmocele is also referred to as a cesarean scar defect or niche. It is defined as a wedge-shaped defect with a depth of at least 1-2mm on the uterus at the prior cesarean scar site.
Isthmocele incidence depends on the imaging modality used for diagnosis. Importantly, identifying an isthmocele on imaging does not imply the presence of symptoms.
Patients may be asymptomatic or present most commonly with abnormal uterine bleeding, usually in the form of postmenstrual or intermenstrual spotting.
Diagnosis is primarily with transvaginal ultrasound or sonohysterogram. Important measurements include the length, width, depth, and residual myometrial thickness.
Current evidence supports surgical management of symptomatic isthmoceles over expectant or medical management. Surgical approaches to the repair can be performed hysteroscopically, laparoscopically, or vaginally.
Approach Number One: Hysteroscopic Isthmoplasty.
Candidates include patients with a symptomatic isthmocele and a residual myometrial thickness of at least 3 millimetres. This reduces the risk of uterine perforation and thermal injury to adjacent structures.
The steps of the procedure include first identifying relevant anatomy, second resecting the cephalad edge of fibrosis, third resecting the caudad edge of fibrosis, and finally, ablating the endometrium and abnormal vessels within the defect.
The first case is a 43-year-old gravida 3 para 3 who has had postmenstrual spotting since her third cesarean section. Sonohysterogram revealed an isthmocele with a depth of 8 millimetres and a residual myometrial thickness of 8 millimetres.
Step One: Identify the Anatomy
This figure shows a uterus with an isthmocele bordered by cephalad and caudad edges of fibrosis. Blood pools within the isthmocele leading to spotting and pain. This uterus is retroverted as this is a risk factor for isthmocele formation.
Step Two: Resect the Cephalad Edge
The surgery aims to flatten the cesarean scar defect to restore the continuity of the cervical canal with the uterine cavity.
Step Three: Resect the Caudad Edge
We then resect the caudad edge of fibrosis to smoothen out the contour between the isthmocele and cervical canal.
Step Four: Ablate the Isthmocele
Abnormal vascularity, which may play a role in abnormal bleeding, is often present within the isthmocele.
To review the steps of the procedure, step one is identifying the anatomy, step two is the resection of the cephalad edge of fibrosis, step three is the resection of the caudad edge of fibrosis, and step four is the ablation of the isthmocele.
We present a second case of a 42-year-old gravida 2 para 2 who has been experiencing postmenstrual spotting since her second cesarean section. Sonohysterogram revealed an isthmocele with a depth of 5 millimetres and a residual myometrial thickness of 10 millimetres.
Technical tips include emptying the bladder with a Foley catheter during the procedure to aid in visualizing the isthmocele and reducing bladder injury.
To help maintain cavity distension, avoid over-dilation of the cervix. Also, due to the use of electrosurgery just within the cervical os, there is a risk of thermal perineal injuries from the capacitative coupling. To mitigate this risk, avoid over-dilation and use sims or weighted speculum during the procedure.
Rotate the hysteroscope light post to focus on the anterior uterine wall.
And consider ultrasound or laparoscopic guidance if the residual overlying myometrium is thin.
A randomized controlled trial between hysteroscopic isthmocele repair and expectant management showed significantly better symptomatic control in the group undergoing hysteroscopic repair. Similar findings have been reported in other prospective studies.
A case series on 41 patients with secondary infertility treated with a hysteroscopic isthmoplasty found that all 41 patients successfully conceived within 24 months of the procedure.
Again similar findings have been reported in other prospective studies, although sample sizes are quite small.
In the literature, 85% of women with secondary infertility and an isthmocele have successfully conceived after hysteroscopic repair.
In conclusion, the surgical treatment appears more effective than medical treatment.
Symptom resolution rates in the literature approach 60-100%
And if the residual myometrial thickness is less than 3 mm, consider laparoscopic revision or guidance.
Approach Number Two: Laparoscopic Isthmoplasty
Candidates include patients with a symptomatic isthmocele and any residual myometrial thickness; and those who failed hysteroscopic repair.
The steps of the procedure include the bladder dissection, then identifying relevant anatomy, resecting the isthmocele, and then suturing the defect.
Step 1: Bladder Dissection
We start by dissecting the bladder off of the anterior aspect of the cervix and lower uterine segment.
Step 2: Identify the Anatomy
The primary goal in this step is to identify and delineate the location of the isthmocele.
Step 3: Resect the Isthmocele
Using a laparoscopic L hook with monopolar electrosurgery, we then excise the entire isthmocele.
Step 4: Suture the Defect
We then suture the defect closed, often with a barbed suture, in one or two layers.
To review the steps of the procedure, step one is the bladder dissection, step two is identifying relevant anatomy, step three is the resection of the isthmocele, and step four is suturing the defect.
A case series of 38 women who underwent laparoscopic isthmoplasty for symptomatic isthmoceles found that 87% of these patients were symptom-free at 1 to 6 years postoperatively. 44% of the patients with secondary infertility went on to have a live birth.
Another case series found that in patients with secondary infertility treated with either hysteroscopic or laparoscopic isthmoplasty, the pregnancy and live birth rate postoperatively was 63%
Again, surgical treatment is indicated for symptomatic isthmoceles
Symptom resolution rates in the literature approach 80-100%
And the laparoscopic approach may be best for patients who desire fertility since this approach increases the residual myometrial thickness and minimizes electrosurgery in the uterine cavity.
In conclusion, isthmoceles are a relatively common radiologic finding. Their presence does not imply the presence of symptoms. Ultrasound or sono is first line for diagnosis. And currently, treatment is only indicated if symptoms are present.
Consider a hysteroscopic isthmoplasty in symptomatic patients with a RMT greater than 3mm, and ideally do not desire future fertility.
Consider a laparoscopic isthmoplasty in patients who are symptomatic, regardless of RMT, and desire future fertility.