Laparoscopic-Assisted Anorectal Pull-Through for Anorectal Malformations



Fig. 37.1.
Trocar sites [18]. From Lima M, Pull-through for high imperforate anus. In: Essentials of Pediatric Endoscopic Surgery. Saxena AK, Hollwarth ME, eds. Austria, Springer; 2009:281–288. Reprinted with permission.



Suspending the bladder with a large monofilament U-stitch facilitates visualization of the pelvis. The initial step in the surgery is dissection of the peritoneal reflection at the distal rectum. It is crucial during this circumferential rectal dissection to stay close to the muscular wall to prevent inadvertent damage to ureters or the vas. Utilizing traction to the rectal wall, the dissection is continued distally until a fistula or the blind end of the rectum is reached. At the point of the rectovesical/urethral fistula, a clear tapering can be noted. The fistula is then divided and tied off with a pre-tied Endoloop. The divided rectal stump is closed in an identical fashion (Figs. 37.2, 37.3, and 37.4).

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Fig. 37.2.
Recto-bladder neck malformation . From Peña A, Bischoff A. Recto-bladder Neck Fistula. In: Surgical Treatment of Colorectal Problems in Children. 2015. Reprinted with permission from Springer.


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Fig. 37.3.
Tying off recto-bladder fistula . From Peña A, Bischoff A. Recto-bladder Neck Fistula. In: Surgical Treatment of Colorectal Problems in Children. 2015. Reprinted with permission from Springer.


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Fig. 37.4.
Divided rectourethral fistula . From Inge TH. Georgeson’s Procedure: Laparoscopically Assisted Anorectoplasty for High Anorectal Malformations. In: Endoscopic Surgery in Infants and Children. Klaas MA, et al. eds. 2008: 391–398. Reprinted with permission from Springer.

Once the rectum is mobilized, the other bowel loops should be retracted out of the pelvis. This will allow the surgeon to visualize the pelvic anatomy , including the prostate, levator muscles, and the pubococcygeus in the pelvic floor. The midline is easily identified and lies in the same plane as the distal end of the fistula and the urethra (Fig. 37.5).

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Fig. 37.5.
Schematic and intraoperative view after division of rectourethral fistula. From Inge TH. Georgeson’s Procedure: Laparoscopically Assisted Anorectoplasty for High Anorectal Malformations. In: Endoscopic Surgery in Infants and Children. Klaas MA, et al. eds. 2008: 391–398. Reprinted with permission from Springer.

The perineal dissection is the next step. The patient’s knees are flexed and the feet are secured on an ether screen over the chest. This allows easy access to the perineum. The external anal area should be mapped using the transcutaneous electrostimulator. The area of maximal contraction should be marked with sutures and represents the site of the future anus.

A 1 cm vertical incision is created in the perineum and a plane strictly staying in the midline is identified by dividing muscular fibers of the muscle complex. Mostly blunt dissection is carried to a depth of approximately 2–2.5 cm. Under laparoscopic surveillance, a Veress needle on an expandable sheath is subsequently advanced through the perineal channel into the pelvis and guided behind the urethra, through the levator fascia, and into the space between urethra and the anterior aspect of the encircling levator ani muscles. Once in position, the needle is removed and replaced with a 10–12 mm cannula, radially expanding the pelvic floor. A blunt 5 mm clamp is advanced through this port, and the proximal end of the divided rectourethral fistula is exteriorized and secured to the perineal skin with absorbable sutures (Figs. 37.6 and 37.7).

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Fig. 37.6.
Perineal pull-through of the distal rectum. From Inge TH. Georgeson’s Procedure: Laparoscopically Assisted Anorectoplasty for High Anorectal Malformations. In: Endoscopic Surgery in Infants and Children. Klaas MA, et al. eds. 2008: 391–398. Reprinted with permission from Springer.


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Fig. 37.7.
Anoplasty and laparoscopic placement of the anchoring sutures . From Inge TH. Georgeson’s Procedure: Laparoscopically Assisted Anorectoplasty for High Anorectal Malformations. In: Endoscopic Surgery in Infants and Children. Klaas MA, et al. eds. 2008: 391–398. Reprinted with permission from Springer.

The rectum should then be laparoscopically suspended to the presacral fascia to prevent future prolapse of the rectum. These sutures are also believed to pull the rectocutaneous junction in a cephalad direction and to sharpen the anorectal angle. Abdominal ports are removed after desufflation of the abdomen, and the three small incisions are closed with absorbable sutures [6].



Instruments






  • Veress needle


  • Three trocars (3–5 mm)


  • Hook cautery


  • 10–12 mm expandable port


  • Laparoscopic dissection instruments


Pearls/Pitfalls






  • A high-pressure distal colostogram should be performed prior to this procedure to clearly identify the anatomy and the level of the rectal urethral fistula.


  • Elevation of the bladder with a large transcutaneous stitch allows better visualization of the pelvic floor.


  • Rectal dissection should be strictly performed at the outer muscular wall of the rectum to prevent damage to the vas and the urethra. Following the vas helps to identify the prostate.


  • The anorectal angle changes when the knees are flexed onto the torso. Aiming the Veress needle too anteriorly carries the risk for urethral injury [7].


  • Proper positioning of the divided colostomy is essential to perform a tension-free pull-through procedure. The initial sigmoid colostomy should be placed as proximal as possible. If placed too distally, takedown might be necessary to gain adequate length for the pull-through.



Postoperative Care


To prevent strictures, anorectal dilation starts 2–3 weeks after the pull-through procedure. Over an 8–12 week period, the anus and rectum are serially dilated with Hegar dilators from 8 to 14 mm diameter. The colostomy is reversed once the neo-rectum is consistently patent [7].

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Oct 25, 2017 | Posted by in PEDIATRICS | Comments Off on Laparoscopic-Assisted Anorectal Pull-Through for Anorectal Malformations
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