Metroplasty of Uterine Septae

• Embryonic failure of absorption of the septum formed by the fusion of the paired Müllerian ducts results in a congenital anomaly that can adversely impact implantation.
• The CONUTA system of classification provides increased granularity allowing for more accurate description of Müllerian anomalies affecting the uterine corpus, particularly when they affect the cervix and the vagina.
  
• The CONUTA U2-C0/1 (rAFS Va/b) version of "septate uterus" can generally be treated with hysteroscopically-directed transection of the septum.
  
• There exist a spectrum of techniques and instruments available for the task but surgeons should not be concerned that radiofrequency based techniques compromise outcome
• In most instances, these anomalies can be treated in an office environment under local anesthesia; surgeons should consider direct injection of anesthetic into the septum and/or for the performance of a fundal block
• For optimal outcomes, including the prevention of perforation, it is paramount that these procedures are accomplished with optimal visualization of the entire internal anatomy of the uterus.
• Controversy exists regarding the management of the C1 lesions - either transection or preservation of the septum are options.
• Any U2 anomaly combined with a C2 cervical anomaly ("double cervix") should be treated with transection limited only to the uterine corpus.

INTRODUCTION

Hysteroscopy is not only a means for assessment of the uterine cavity, it is also the method of access for reconstructive surgical intervention on selected women. However, careful patient selection using appropriate imaging techniques in the context of proper indications is paramount. The Müllerian anomaly most suitable for hysteroscopically directed technique is the septum that, depending on the classification system is a Class V (rAFS system) or U2-C-0 or 1 (CONUTA System). 

While there are no randomized trials, available evidence supports surgical management of women with uterine septae in the context of recurrent pregnancy loss (1-3). Furthermore, given the low morbidity of hysteroscopic surgery here is a reasonable for prophylactic transection of at least the “large septum” in patients with primary infertility(4). For example, in a series of women undergoing IVF and Embryo Transfer (ET) before and after transection of a large septum (rAFS Va; CONUTA U2b) the preprocedure spontaneous loss rate was 83.3% while post transection it was 30.6%. This is in contradistinction to the smaller septum(rAFS Vb; CONUTA U2a) where the baseline compared to post transection spontaneous loss rates were 28.9% and 28.1% respectively (4).

First of all, it is important to clarify that despite the name in CPT coding, the surgical technique is NOT septum resection but hysteroscopic transection. Applied correctly, transection of the uterine septum appears to result in an “almost normal prognosis for pregnancy outcomes and term delivery rates” (5). Discussed above is the apparent distinction in outcomes between the “partial septum” (ASRM Class Vb or CONUTA U2a) from the septum that reaches the internal os of the cervix (ASRM Class Va or CONUTA U2b).

There is no published evidence evaluating the utility of endometrial preparation for transection of the uterine septum. However, it is apparent that thickened endometrium can obscure the tissue landmarks necessary for this surgery, and also can fragment during the procedure an obscure visualization and potentially clog the outflow channels of the hysteroscopic system. Consequently, we use medical preparation on all of our patients, typically using oral progestins that are not converted to ethinyl estradiol such as is the case for norethindrone (in some areas called norethisterone), or norethindrone acetate and in doses adequate to suppress endogenous estradiol production from the ovary. Consequently, since there is evidence that medroxyprogesterone acetate (MPA) in daily doses of 30 mg or more does suppress ovulation, we use MPA, 20 mg twice daily for four weeks prior to the procedure. Alternatives could include danazol, or GnRH agonists or antagonists although the latter are expensive and not likely superior for the purpose at hand.

Septum transection is a procedure particularly suited for performance under local anesthesia and in an office setting, particularly for rAFS Va and Vb without cervical and vaginal involvement (CONUTA U2-C0-V0) anomalies. Of course such an approach is based upon the existence of an accurate diagnosis from imaging studies, or, perhaps, prior laparoscopic evaluation. More than a decade ago a multicenter Italian group published a series using no anesthesia (7); but our experience is that anesthesia involving the septum makes the process consistently acceptable for the patient. Indeed, we also use the technique when there is a cervical component as well (CONUTA U2-C1-V0). For those without access to a clinic or office procedure environment, the procedure can obviously be performed with alternate regional or systemic anesthetic techniques. 

The technical requirements are relatively modest, in part depending on the method used for transection. Required is a hysteroscope and a matching 5- or 5.5-mm OD continuous flow operative sheath with a 5 Fr operating channel and either 5 Fr hysteroscopic scissors or a RF needle that is preferably bipolar in design. While 25-30° foreoblique (angled) lenses were formerly suggested as being preferable, we suggest a less angled lens either 12° or 15° and angle that facilitates visualization for keeping the transection instrument central on the septum yet preserves the ability to observe the cornua. An alternate approach is the use of a resectoscope – that should be the narrowest available, which is generally 22 Fr; larger instruments may be up to 27 Fr typically requiring dilation up to about 9 mm.

Many seem to feel that RF instrumentation is inappropriate in this setting because of associated risk and thermal injury. However, both experience and available evidence suggest other Radiofrequency based technique may be associated with reduced operating time and complications but equivalent surgical and clinical outcomes (8). The specific approach utilizing hysteroscopic scissors, laser energy or RF monopolar or bipolar devices is one that is based upon some combination of available instrumentation and surgeon preference.  

The distending media used should be compatible with the method of transection. Electrolyte containing media, usually normal saline or Ringer’s lactate, should be used when mechanical or bipolar RF instruments are used. Media solutions without electrolytes such as sorbitol, glycine, mannitol or dextrose in water must be used distention when monopolar RF instrumentation is selected. 

After the patient is properly positioned, and appropriate anesthesia is instituted the cervix is accessed either vaginoscopically or using a speculum and tenaculum technique. Preferably, the hysteroscopic system is inserted without blind dilation, which should be performed only if necessary, to accommodate the OD of the hysteroscopic system to be used in the procedure. 

After accessing the cervical canal, and initiating the continuous flow of media, the hysteroscopic system is advanced until the leading edge of the septum is identified, typically characterized by the presence of two “tunnels” representing the dual “endometrial cavities” present on each side of the corpus. It is useful to explore both sides, if possible, to aid in orientation prior to starting the procedure. 

If the procedure is being performed under local or “no” anesthesia we suggest anesthetizing the septum as described in the section on analgesia and anesthesia. We use a 4 Fr “Williams” or similar needle primed and passed through the operating channel to inject, under direct visualization, ½% lidocaine (or mepivacaine), with 1/200,000 adrenaline directly into the septum, typically 3-4 mL at a time. We also add 2-3 mL as a fundal or cornual block around the ostia on the left and right sides. The patient is instructed to inform the team if pain is being perceived. In such instances, additional local anesthetic is used. For large septae, we often add anesthesia to the septum once or twice each case. 

Operating Channel Technique – 5 mm Instruments

Before starting the transection, the surgeon should ensure that visualization is optimal, that the leading edge of the septum is clearly visible on the screen bounded laterally by the two endometrial canals. Transection of the septum should start as precisely as possible at the midpoint between the anterior and posterior “attachment” to the normal cervix or myometrium depending upon the most caudal extent of the septum. The RF generator is activated and the needle electrode, or the scissors if RF is not used, are used to divide the tissue in a progressive fashion while continually ensuring that the plane of transection is midway between the anterior and posterior aspects of the endometrial cavity. 

 In general, the transection will be of relatively avascular tissue, so if bleeding is encountered, the incision has probably deviated off plane in either an anterior or posterior orientation. Some surgeons like to mark the most cephalic aspect of the dissection by forming incisions on either side of the septum that serve as guides both for the anterio-posterior orientation and the cephalic extent of the transection. It is obvious from MR and other imaging that as the transaction extends cephalically, the width of the septum increases – sometimes dramatically.  

There are a number of features that must be considered when determining the endpoint - cephalic extent of transection. It is important to remember that available evidence suggests that there is questionable value operating on Class Vb (CONUTA-U2a) septae. Consequently, we aim to leave several mm of the base, rather than risk entering into the myometrium. With this in mind, and using a combination of interpretation of images, the observation of bleeding, being aware of the location of the cornua and vigilant of seeing a pink hue to the tissue, can help define this qualitative but important end point. Regardless, if muscular tissue is observed, the procedure should be stopped (8). Remember, it is better to leave a small amount of the septum, than to go too far.

Resectoscopic Technique

Laparoscopic Guidance

CONUTA U2-C1

A randomized trial compared cervical septum transection and retention and demonstrated total operative time and the volume of distending media to be reduced in the transaction group because of improved visibility and the inherent and relative ease of creating the incision in the uterine septum. Importantly, no difference was found in subsequent pregnancy rates, first trimester abortions, the need for cerclage, or the proportion of preterm deliveries. The group with cervical septum retention had a significantly higher number of cesarean sections, but the reasons for this are not clear. 

Concurrent laparoscopy may be used as a method designed to monitor and protect against the risks of perforation of the corpus or cervix. However with the preprocedure imaging described, maintenance of good hysteroscopic visualization, and, if necessary, intraoperative transabdominal ultrasound, such a step is generally unnecessary – unless of course there is another indication for the laparoscopic procedure. 

Cervical Septum Preservation

A pediatric #8 Foley catheter or metal probe is inserted through one hemicervix into the endometrial cavity while the operative hysteroscope or resectoscope is then positioned in the contralateral hemicervix and the other hemicervix is distended with fluid media. I It is suggested that some combination of transvaginal and transabdominal ultrasound be present to facilitate proper positioning of these instruments. It is also recommended that methylene blue or indigo carmine dye be used to inflate the balloon – this allows confirmation that septum transaction has occurred if the balloon is inadvertently ruptured during the dissection. 

In this case, the recommended hysteroscope would be a 25ᴼ to 30ᴼ device to facilitate the lateral visualization required in this technique. After the hysteroscope or resectoscopic assembly is positioned in the cavity contralateral to the balloon or dilator and the pointed electrode oriented medially, in the direction of the other cavity. Manipulation of the dilator or serial inflation and partial deflation of the balloon can be helpful in identifying the thinnest aspect of the septum which is located in the region of the lower uterine segment. Transabdominal ultrasound can be helpful in this regard as well. The uterus can rotate in a fashion that can disorient the surgeon. Care should be taken to maintain the uterus in an orientation parallel to the floor to reduce this concern. The septum is then incised the electrode just above the internal cervical os until the Foley bulb or metal rod is visualized. If the Foley Balloon is still intact, it can be withdrawn into the contralateral cervical canal to maintain distension while continued transection of the septum is performed. This transaction is continued in a cephalad direction until both tubal ostia are visualized and the hysteroscope can move freely about the now unified endometrial cavity (73). 

Cervical Septum Transection

Controversy exists regarding the utility of adjuvant systemic therapy or intrauterine stents or barriers including balloons even though estrogens, progestins, intra-uterine devices and pediatric Foley catheters, are used by many (10). The available evidence is limited but there exists a randomized clinical trial compared an intra-uterine device (IUD) vs no placement immediately upon completion of hysteroscopic metroplasty. All of these patients received post-operative conjugated equine estrogens 1.2 mg twice daily for 30 days and oral medroxyprogesterone acetate was taken 10 mg daily on days 26-30. There was no difference in any outcome that could be ascribed to the IUD (11). Available evidence shows that no tested adjuvant - postoperative estrogens, a copper IUD, intrauterine balloon - have any utility in the preventing postoperative adhesion formation following transaction of a uterine septum.  

1. Homer HA, Li TC, Cooke ID. The septate uterus: a review of management and reproductive outcome. Fertil Steril. 2000;73(1):1-14. 

2. Pabuccu R, Gomel V. Reproductive outcome after hysteroscopic metroplasty in women with septate uterus and otherwise unexplained infertility. Fertil Steril. 2004;81(6):1675-8. 

3. Mollo A, De Franciscis P, Colacurci N, Cobellis L, Perino A, Venezia R, et al. Hysteroscopic resection of the septum improves the pregnancy rate of women with unexplained infertility: a prospective controlled trial. Fertil Steril. 2009;91(6):2628-31. 

4. Ban-Frangez H, Tomazevic T, Virant-Klun I, Verdenik I, Ribic-Pucelj M, Bokal EV. The outcome of singleton pregnancies after IVF/ICSI in women before and after hysteroscopic resection of a uterine septum compared to normal controls. Eur J Obstet Gynecol Reprod Biol. 2009;146(2):184-7. 

5. Grimbizis GF, Camus M, Tarlatzis BC, Bontis JN, Devroey P. Clinical implications of uterine malformations and hysteroscopic treatment results. Hum Reprod Update. 2001;7(2):161-74.

7. Bettocchi S, Ceci O, Nappi L, Pontrelli G, Pinto L, Vicino M. Office hysteroscopic metroplasty: three "diagnostic criteria" to differentiate between septate and bicornuate uteri. J Minim Invasive Gynecol. 2007;14(3):324-8. 

8. Colacurci N, De Franciscis P, Mollo A, Litta P, Perino A, Cobellis L, et al. Small-diameter hysteroscopy with Versapoint versus resectoscopy with a unipolar knife for the treatment of septate uterus: a prospective randomized study. J Minim Invasive Gynecol. 2007;14(5):622-7. 

9. Worldwide AAMIG, Munro MG, Storz K, Abbott JA, Falcone T, Jacobs VR, et al. AAGL Practice Report: Practice Guidelines for the Management of Hysteroscopic Distending Media: (Replaces Hysteroscopic Fluid Monitoring Guidelines. J Am Assoc Gynecol Laparosc. 2000;7:167-168.). J Minim Invasive Gynecol. 2013;20(2):137-48. 

10. Valle RF, Ekpo GE. Hysteroscopic metroplasty for the septate uterus: review and meta-analysis. J Minim Invasive Gynecol. 2013;20(1):22-42. 

11. Vercellini P, Fedele L, Arcaini L, Rognoni MT, Candiani GB. Value of intrauterine device insertion and estrogen administration after hysteroscopic metroplasty. J Reprod Med. 1989;34(7):447-50.