Single-stage Reconstruction in a Rare Case of Female Caudal Duplication Syndrome

ABSTRACT

Caudal duplication syndrome is exceptionally rare. We report a female infant with complex genitourinary and colorectal duplication managed by detailed imaging and single-stage definitive reconstruction. Excision of nonfunctional duplicated organs, transureteroureterostomy, bowel reconstruction, and perineal unification achieved good urinary, bowel, and cosmetic outcomes at short-term follow-up without significant complications.

INTRODUCTION

Caudal duplication syndrome (CDS) is a rare condition (incidence <1 in 100,000) with partial or complete duplicated caudal structures, including the distal gastrointestinal (GI) tract, genitourinary system, external genitalia, and the lumbosacral spine. There are only 23 female CDS cases reported[1,2,3,4,5] until 2020. We herewith report successful definitive reconstruction surgery in a rare case of female CDS.

CASE REPORT

At the age of 15 months, a female infant presented with duplication of the external female genitalia. The clinical evaluation revealed complete duplication of the external female genitalia on both sides, with two perineal complexes. In the right vestibule, there were two openings: the right urethra and a rectovestibular fistula. Good sphincter tone and reflex noted at the right imperforate anus site. On the left vestibule, there was a single long-atretic urogenital (UG) sinus [Figure 1a and d]. There was a left anterior ectopic anus, and the child was able to pass stools via this opening [Figure 1c]. On examination of the back, the sacrum was found to be bifid without any swelling, tuft of hair, dermal sinus, or mass. During urination, the infant emptied via the right urethra (left stenotic), while stools were emptying through the right rectovestibular fistula and left ectopic anus.

Figure 1.

Anatomical illustration of female caudal duplication. (a) diagrammatic representation of duplicated structures; (b) diagrammatic representation of surgical correction – the left descending colon and left bladder excised, left-to-right transureteroureterostomy and right ureteric reimplantation done; right rectal stump opening as rectovestibular fistula retained as neovagina and both vagina anastomosed to this, small retained limb of the left descending colon brought out as end colostomy (chimney vent) while the right descending colon pulled through (abdominoperineal pull through) to create right-sided anus, all left-sided perineal structures were excised; (c) clinical picture of perineum before surgery; (d) clinical picture of perineum after surgery

X-ray of the lumbosacral spine indicated a bifid sacrum, corresponding to a caudal duplication. There was mild right-sided hydronephrosis, while the left kidney was normal on ultrasound. On the left UG sinus, the catheter could not be passed; a blind pouch was noted [Figure 2a]. A micturating cystourethrogram via the right urethra revealed Grade 4 vesicoureteral reflux on the right side; bladder contour was normal [Figure 2b]. Computed tomography (CT) urography revealed normal morphology of both kidneys and confirmed that the right ureter drained into the right urinary bladder, whereas the left ureter appeared to open near the bladder neck, although its exact site of insertion could not be clearly delineated. A CT contrast enema demonstrated a markedly dilated right colonic system, involving the transverse colon, descending colon, sigmoid colon, and rectum, while the left colonic system was minimally dilated; the proximal colon was single up to the ascending colon; beyond the transverse colon, it was divided into two separate colonic channels, forming duplicated right and left descending colons. Virtual reality reconstruction enabled a thorough delineation of the anatomy [Figure 2c]. Magnetic resonance imaging of the spine and pelvis confirmed a bifid sacrum and identified a small lipomeningocele, without gross evidence of tethered cord.

Figure 2.

Radiological and surgical findings: (a) left urogenital structures atretic, bifid sacrum seen; (b) right bladder normal contour and function, vesicoureteric reflux into right ureter noted; (c) Virtual reality reconstruction revealed two descending colon and two bladder; right kidney was entering right bladder; the left kidney was entering the left bladder; (d) operative finding revealed distal to transverse colon; there were two descending colons (DC1 and DC2); bladder also duplicated (UB1 and UB2)

Surgical management

Under general anesthesia and epidural analgesia, the patient was positioned in lithotomy and prepared for both abdominal and perineal access. On genitoscopy on the right side, the right urethra allowed easy negotiation of the scope into the right urinary bladder, which appeared normal in capacity/mucosal pattern; the right ureteric orifice was patulous and ectopic at the bladder neck. On the left side, entry into the left urinary bladder could not be achieved, as the left UG sinus was stenotic.

A midline vertical laparotomy was performed, and intra-abdominal inspection confirmed the radiologic findings. There was a single cecum, a single appendix, and a single ascending colon. Distal to the transverse colon, a Y-shaped bifurcation gave rise to two colonic channels, a right descending colon and a left descending colon [Figure 2d].

Since the left urethra was stenotic, the left urinary bladder was completely mobilized and excised. The left ureter was preserved, mobilized, and carefully transposed to the right side through a window created in the colonic mesentery; left-to-right transureteroureterostomy (TUU) was performed after spatulation to match sizes (the left ureter was too short to reach the right bladder for reimplantation). The ectopic refluxing right ureter was reimplanted into the right urinary bladder; a feeding tube was placed across the TUU as an internal stent, and a suprapubic catheter was inserted to ensure adequate bladder drainage (video link: https://youtu.be/zlIaENqZAu4).

The left descending colon was resected; a short segment of the left colon was left for an end colostomy (as a chimney vent). The right descending colon, above the rectal stump, was brought down through the pelvis and sphincter muscle complex as a standard abdominoperineal pull-through to create a neoanus on the right side. The right rectal stump opening into the right vestibule was kept as a neovaginal pouch [Figure 1b]. Both right and left vaginas (attached to the right and left hemiuteri) were 1.5 cm apart and were anastomosed to the neovaginal pouch separately. The left female perineum, along with the clitoris, stenotic UG sinus, and anterior ectopic anus, was completely excised, and perineal reconstruction was done in layers meticulously to make a single external genital appearance [Figure 1d].

The total operative time was 4.5 h (blood loss 50 ml); no intraoperative complications. The immediate postoperative recovery was uneventful. The left-sided venting colostomy had minimal output only during the first few weeks, after which the child started passing stools via pulled-through anus; it was closed after 3 months. At 6-month follow-up, the child was passing urine well (maximum voided volume: 90 ml) without any dribbling or incontinence and also had a good bowel habit without constipation. Cosmetic outcome was satisfactory. Further long-term evaluation with uroflowmetry/urodynamics/manometry is planned in view of complex pull-through and lipomeningocele.

DISCUSSION

Female CDS is a very rare complex congenital anomaly resulting from abnormal development of the caudal embryonic axis.[1,2,3,4,5] Bekere et al.[1] emphasized the need for individualized surgical planning focused on functional outcomes rather than anatomic normalization alone. Gastol et al.[2] felt delayed, staged reconstruction allows identification of the dominant bladder unit, improving continence outcomes while preserving renal function. Mei et al.[3] cautioned that functional asymmetry between duplicated systems may only become evident with growth. We felt single-stage reconstruction of the genital and GI tract would be easier as staging them would entail a difficult dissection in the pelvis due to fibrosis, risking bladder denervation. The present case demonstrates that single-stage comprehensive reconstruction can be achieved safely in infancy with a well-planned multidisciplinary approach. In the index case, instead of uniting the duplicated bladders and risking damage to the bladder neck/innervation, we opted to preserve the functioning of the right bladder. We were unsure of the emptying mechanism of the left bladder, and we feared that uniting two bladders might result in a large, dysfunctional bladder. Wisenbaugh et al.,[4] on the contrary, showed that combined duplicated bladders after maturation can successfully achieve urinary continence and reflux resolution.

We used the principle of bowel vaginoplasty and preserved the stump of the rectovestibular fistula as a future neovagina. We elected to excise the redundant, duplicated left descending colon, as the right descending colon was adequate and could be pulled through into a right anal sphincter complex. While early continence and cosmetic outcomes are satisfactory, we do agree with other authors[5] that long-term follow-up is essential, as early management may fail to address evolving functional deficits. The present case adds to the limited available evidence supporting early single-stage reconstruction in CDS.

CONCLUSION

CDS is a rare anomaly that warrants meticulous anatomical evaluation and careful planning. A single-stage surgery avoids the difficult access associated with staging UG/anorectal components. Long-term follow-up is essential to assess functional and cosmetic outcomes.

Ethical clearance

Obtained for the reproduction of clinical images.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.