Complete Tubular Colonic Duplication ending in a Common Channel as a Recto vestibular Fistula: A Case Report and Literature Review of Management Options.

Colon duplication (CD) is a rare congenital abnormality with varied presentations. We present a neonatal case with complete tubular CD terminating uniquely as a common channel, a single rectovestibular fistula. We summarize surgical management options in CD as well as factors that will help to decide the best surgical treatment in individual cases. Copyright:

INTRODUCTION

Gastrointestinal duplications occur anywhere from the mouth to anus. They have been observed in 1 in 4500 autopsies. They are hollow attachments to the gastrointestinal tract, with a smooth muscle coat and an epithelial lining which may consist of ectopic gastric mucosa. Duplications vary in size, site, symptoms and can be associated with genitourinary, vertebral, and anorectal malformations. About 15% of duplications are colonic; these may be cystic or tubular.[12] We present a case and summarize from the literature, for the first time, surgical management options in tubular colon duplication (CD) as well as factors that may influence the surgeon's choice of procedure.

CASE REPORT

A neonate, born at 40 + 6 weeks gestation, had normal antenatal scans. No significant family history or abnormality was noted on her newborn baby check and she was discharged at 12 h of age from her local hospital. She re-presented at 22 h of life with apparent passage of stool from her vestibulum, was found to have an imperforate anus, and was referred to our surgical unit. A renal and spinal ultrasound as well as cardiac ECHO were normal. During the formation of a sigmoid colostomy, as part of the management for the imperforate anus, a duplicated colon was unexpectedly found. Subsequent contrast study suggested complete tubular CD.

At 10 months of age, at laparotomy, the duplication was seen to extend from the ileocaecal valve (with single appendix) to the rectum with a common mesentery. Distally, both colon limbs formed a common channel below the peritoneal reflection, opening as a rectovestibular fistula. The whole of the common wall was stapled to create a single wider colon lumen [Figure 1]. A posterior sagittal anorectoplasty corrected the anorectal malformation.

Figure 1

(a) A urinary catheter, through the vestibular fistula passed into the medial and lateral colon limbs. The catheter balloon is seen as a bulge. (b) The stapler enters the two lumen of the ascending colon, dividing the common wall towards the descending colon

At 15 months of age, during stoma reversal, it was seen that the staple lines of a short segment of the CD had re-fused and was again divided. At 18 months of age, the patient was noted to have poor weight gain and developed constipation. She was also not yet walking. At 3 years of age, she had a noticeable prominence of her lower thoracic vertebrae and was still in nappies due to urinary incontinence. An MRI showed a prepontine cyst and spinal dysraphism with a tethered cord. Her constipation had initially improved with laxatives but became challenging to treat medically. A contrast enema showed marked distension and fecal loading of the rectum with normal colon caliber proximally. An antegrade continence enema (ACE) procedure at 3.5 years of age helped improve her bowel emptying and enuresis. Currently, she is nearly 10 years of age and manages her bowel emptying through her ACE stoma. She is under neurosurgical follow-up for her tethered cord but has no symptoms requiring surgery.

DISCUSSION & LITERATURE REVIEW

CD in neonates is a very rare condition with no clear consensus in literature about the best treatment option. The presence of a CD may be asymptomatic and only found incidentally. However, if the duplication is narrow or blind-ending, it may present as an abdominal mass and can lead to intestinal obstruction with the risk of perforation. There have also been reports of malignant tumors in duplications and bleeding from ectopic gastric mucosa.[12]

Treatment of these symptoms and/or prevention of complications is the main reason for surgery. Several cases have been discussed in the literature, each treated variably.

Surgical options are summarized in Table 1.

Table 1

Benefits and risks of the various surgical procedures in colon duplication and when to consider each

Surgical procedure	Advantages	Disadvantages	Consider when
1. Stapling of the common wall to produce a single wider lumen	Preserves bowel lengthTreats and prevents symptoms that may be related to double lumens[3]	Does not reduce the risk of complications from duplication tissue, such as bleeding from any ectopic gastric mucosa or associated malignancyIf the distal most septum is not reached, then this can become a site of fecal impaction and therefore a perineal or posterior sagittal approach is recommended to reach this area[4]	Symptoms can be treated by widening the lumenA large extent of bowel is affectedThere’s a shared blood supply between the duplication and normal colon
2. Resection of the duplicated lumen only	Potentially curative	If the duplicated lumen is not clearly identified, risk of removing the normal colon or compromising its blood supply[35]	Duplicated lumen can be clearly identified and vascular blood supply is clearly separate between the duplication and normal colon
3. Resection of both lumens (normal and duplicated) at the site of duplication	Potentially curative	Short bowel if large amount removed and likely associated side effects of this, such as diarrhea	A short area of bowel is affected
4. Mucosectomy (excision of the mucosal layer with sparing of the muscular and serosal layers)	Avoids extensive resection of bowelPrevents acid peptic ulceration and bleeding if areas of ectopic gastric mucosa[6]	Cannot widen a narrowed colon lumen, as would stapling	Concerned re: Ulceration or bleeding from ectopic gastric mucosaResection is not possible due to shared blood supply, but there is a need to remove the duplicated lumen

The following factors can be used to guide the choice of procedure:

The presence of symptoms or complications

Identifying the exact cause of the symptoms or complications will help to know what will relieve them

In asymptomatic patients, extensive resection risks other problems and has to be balanced carefully against the benefits.[7] No intervention, as alternative may be an option in these patients.

Extent of the duplication (complete or partial)

Where a larger extent of bowel is affected, as much of the bowel should be preserved as possible considering alternatives to extensive resection.

Shared or separate mesenteric blood supply between duplicated and normal bowel

Where it is shared, resection of the duplicated lumen would compromise blood supply to the normal colon and so alternative procedures should be considered.[8]

Clear identification of the CD

Where there is a blind-ending lumen and a fistula, the duplicated segment will have the blind-ending lumen.[4] However, if one lumen is ending as anus and the other as fistula, the fistula leads to the duplication.[9] If the two cannot be clearly identified then alternatives to large resection may be more appropriate,[5] to again preserve as much normal colon as possible.

A combination of approaches may be the ideal option in individual cases.[4] In our case with complete tubular CD, both lumens ended as a common channel, a rectovestibular fistula. The entire dividing septum was stapled, creating a single lumen, preserving the normal colon, and without compromising its blood supply. Our neonate may have remained asymptomatic without this; however, it was thought that stapling would help prevent future complications of two smaller lumens rather than one wider lumen. During stoma reversal, a short distal septum was incidentally found to have re-fused. Being easily accessible, it was re-divided despite the patient being asymptomatic as literature reports have highlighted these septa as possible sites of fecal impaction.[49] Another consideration in CD, is a nuclear scan to assess for ectopic gastric mucosa. Our patient did not have one as she was asymptomatic.

Our follow-up of nearly 10 years is greater than most, in similar cases. It is often reported as unspecified or <1 year by the time the case reports are published. We found that after a promising early postoperative period with regular stooling, our patient developed problems later, requiring intensified bowel management. It is uncertain whether her symptoms of constipation were caused mainly by her anorectal malformation, the tethered cord, and bowel dysmotility or her duplicated colon, maybe a combination. A rare but more severe condition, caudal duplication syndrome has also been described where there is a diverse spectrum of symptoms involving gastrointestinal, genitourinary, and spinal anomalies associated with a greater morbidity.[10] We decided in her case, to proceed with ACE formation which helped to establish regular bowel movements and resolve her enuresis and so early bowel management with bowel irrigation may help improve the quality of life in such cases.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.