Minimally Invasive Surgery in the Management of Anorectal Malformations

Prediction of anorectal malformations with bladder-neck/urethral-prostatic fistula using classification and regression tree analysis

BACKGROUND

The anorectal malformations (ARMs) with bladder-neck/urethral-prostatic fistula in males are the most complex groups in ARMs. It is essential to diagnose them effectively before the primary operation for both surgical modalities and future functional prognosis can be quite different from other types. Our study aimed to develop a classification and regression tree (CART) model for the prediction of ARMs with bladder-neck/urethral-prostatic fistula.

METHODS

A total of 132 newborns with ARMs were included retrospectively and randomly assigned to the training sample and test sample in a 3:1 ratio. The pouch-perineum distance of ultrasound (PPDU), the pouch-perineum distance of invertogram (PPDI), and the rectum gas above the coccyx (RGAC) on the invertogram were hypothesized can serve as individual predictors. The CART analysis was used to determine the best combination of candidate predictors. The model's performance was assessed by the area under the receiver operating characteristic curve (AUC) and validated in the test sample.

RESULTS

All three individual predictors were included in the CART model to predict the ARMs with bladder-neck/urethral-prostatic fistula in the derivation cohort with the following test characteristics (95% CI): sensitivity 75.6% (60.1 to 86.6); specificity 88.9% (76.7 to 95.4); AUC 0.909 (0.854 to 0.965). The model's predicted accuracy was validated in the test cohort (AUC = 0.883). In all 132 subjects, the AUC of the tree model was significantly superior to that of the best individual index: PPDU (0.901 vs. 0.819; p = 0.005).

CONCLUSIONS

A predictive model that consists of PPDU, PPDI, and RGAC may be useful in predicting ARMs with bladder-neck/urethral-prostatic fistula.

Percutaneous Anorectoplasty (PARP)—An Adaptable, Minimal-Invasive Technique for Anorectal Malformation Repair

Background: Anorectal malformations comprise a broad spectrum of disease. We developed a percutaneous anorectoplasty (PARP) technique as a minimal-invasive option for repair of amenable types of lesions. Methods: Patients who underwent PARP at five institutions from 2008 through 2021 were retrospectively analyzed. Demographic information, details of the operative procedure, and perioperative complications and outcomes were collected. Results: A total of 10 patients underwent the PARP procedure during the study interval. Patients either had low perineal malformations or no appreciable fistula. Most procedures were guided by ultrasound, fluoroscopy, or endoscopy. Median age at PARP was 3 days (range 1 to 311) days; eight patients were male. Only one intraoperative complication occurred, prompting conversion to posterior sagittal anorectoplasty. Functional outcomes in most children were highly satisfactory in terms of continence and functionality. Conclusions: The PARP technique is an excellent minimal-invasive alternative for boys born with perineal fistulae, as well as patients of both sexes without fistulae. The optimal type of guidance (ultrasound, fluoroscopy, or endoscopy) depends on the anatomy of the lesion and the presence of a colostomy at the time of repair.

Refinements in surgical techniques for visualized tunnel formation in laparoscopic-assisted anorectoplasty

PURPOSE

Laparoscopic-assisted anorectoplasty (LAARP) is becoming a more popular procedure for anorectal malformation (ARM) repair. However, the conventional technique for creating pull-through tunnel between the perineal skin and the pelvic floor has been criticized as being semi-blind. This study aims to present a refined version of our previously reported clamp introduction technique for visualized tunnel formation in the center of the sphincter muscle complex (SMC) for rectal pull- through for ARMs.

METHODS

A retrospective review was performed for ARM patients who underwent LAARP from Jan 2019 to Jun 2020. Longitudinal muscle tube (LMT) tunnel was created using the clamp-dilator introduction technique: a laparoscopic dilator was used to create a pelvic tunnel within LMT in high ARM, and the clamp introduction under the direct vision technique was performed for creating the perineal tunnel of LMT for both high and intermediate ARMs.

RESULTS

Seventy patients (1-198 days) with high-type (27cases) and intermediate-type (43 cases) ARM underwent LAARP using clamp-dilation introduction technique. No patients suffered from urinary tract injury, recurrent rectourethral fistula, urethral diverticulum and urinary incontinence. One patient suffered from wound infection and rectal retraction which required a redo pull-through on postoperative day 7. Rectal prolapse requiring surgical intervention developed in one patient. Postoperative MRI examination confirmed central placement of the rectum within the LMT in all cases.

CONCLUSION

Our experience demonstrates that a visualized tunnel formation in the LMT center can be achieved by the clamp-dilator introduction technique in LAARP for both high and intermediate ARMs.

Robot-assisted anorectal pull-through for anorectal malformations with rectourethral and rectovesical fistula: feasibility and short-term outcome

BACKGROUND

Multiple structures in the anorectal area are closely related to defecation, voiding and sexual function. Although laparoscopic-assisted anorectal pull-through is widely accepted as a minimally invasive surgical technique, controversy still exists for ARMs with rectourethral fistulas. Intraoperative injuries more or less involve the perirectal sphincters and neurovascular tissue.

METHODS

Seventeen selected infants with ARMs underwent robot-assisted anorectal pull-through (RAARP) between October 2016 and January 2018. The application of nerve- and sphincter-sparing technique in RAARP was detailed. The feasibility and early outcomes were evaluated.

RESULTS

All procedures were completed without conversion. The robotic system facilitated clear dissections between different anatomical layers. Under direct vision, the fistula was easier to repair, and the rectal pouch was precisely placed in the center of the striated muscle complex. During the follow-up of 11.6 months, 13 patients resumed normal defecation. The other four children experienced mild constipation or fecal incontinence. Their continence and defecation functions showed favorable evolution.

CONCLUSION

RAARP is a safe and effective alternative for the treatment of ARMs, which provides an advantage in further minimizing the injury to perirectal nerves and sphincters.

Laparoscopic surgical technique to enhance the management of anorectal malformations: 330 cases' experience in a single center

PURPOSE

Laparoscopic-assisted anorectoplasty (LAARP) is considered to benefit the patients with vesico-prostatic fistula. The aim of this study is to present the details of our LAARP technique for improving the short- and long-term outcomes in the patients with high and intermediate types of anorectal malformations (ARMs).

METHODS

330 patients with high-type (174 cases) and intermediate-type (156 cases) anorectal malformation (aged 8 days to 15 years) underwent LAARP from 2001 to 2019. LAARP was performed for full mobilization and resection of the dilated rectum, intra-rectal closure of the fistula, visualization, and enlargement of the center of the longitudinal muscle tube (LMT) from pelvic and perineal aspects.

RESULTS

LAARP was performed in all patients and no patient was converted to open procedure. The urethral diverticulum was found in three patients (1.02%, 3/294) according to postoperative protocol voiding cystourethrogram but was not associated with any symptoms such as urinary tract infection and dysuria. Rectal prolapse requiring surgical intervention developed in 25 (7.6%) of 330 patients. Anal stricture occurred in three patients and re-do anoplasty was performed 5 months after LAARP. Anal retraction occurred in two patients and re-pull-through was conducted at 5 and 6 days, respectively, after LAARP. 228 patients who were older than 3 years were followed up. The median follow-up period was 5.8 years (range 3-15 years). 217 patients (95.2%) had voluntary bowel movements; 202 patients (88.6%) were free from soiling or with grade 1 soiling; 30 patients (13.6%) and 25 patients (11.3%) suffered from grade 1 and grade 2 constipation, respectively, while no patient had grade 3 constipation.

CONCLUSION

Our experience demonstrates that the LAARP has advantages on rectal mobilization and resection, intra-rectal fistula closure and accurate tunnel formation in the LMT with minimal trauma. The improvement of the short-term and long-term outcomes after LAARP has been shown not only for high-type ARM but also for intermediate-type ARM.

Normal anorectal musculatures and changes in anorectal malformation

PURPOSE

We investigated the anorectal musclulature in normal children and anorectal malformations (ARM) to evaluate its role in bowel control mechanism.

METHODS

Pelves of 50 neonates died of ARM-unrelated diseases and 16 patients with anorectal malformations (8 high, 5 intermediate, and 3 low ARMs) were dissected and analyzed.

RESULTS

Normal anorectal musculature was divided into three muscular tubes: the internal sphincter tube (IAST), longitudinal muscle tube (LMT) and transverse muscle tube (TMT). The LMT came from the outer longitudinal smooth muscle fiber of the rectum and the striated muscle fiber of the levator ani, and the TMT composed of the puborectalis and the external anal sphincter. However, in ARM, the IAST was absent and the LMT, the center of the sphincter muscle complex, was only from the levator ani and could be divided into the pelvic portion and the perineal portion. The former, from the upper rim of the puborectalis to the bulbar urethral, became narrowed and dislocated anteriorly near to the posterior urethra in high ARM and rectal pouch in intermediate ARM. The latter, below the bulbar urethra to the anal dimple, was fused to a column both in high and intermediate ARM. The columnar perineal LMT run downwards and then split, penetrated the superficial part of EAS and terminated at the deep aspect of the skin, to form the anal dimple, which represents the center of the perineal LMT from the perineal aspect. The length of the LMT was longer in high and intermediate ARM than the normal neonate. The columnar perineal LMT and narrowed pelvic LMT could be possibly identified by laparoscopic and perineal approaches retrospectively and widened to allow the passage of the rectum through.

CONCLUSIONS

The anorectal musculature in ARM is composed of agenesic LMT and TMT and the narrowed LMT gives anatomical evidence of the center, where the neorectum should pull through.

Laparoscopic Technique in the Management of High Anorectal Malformations: A Propensity Score-Matched Outcome Study Using a Large Inpatient Database

Background: Posterior sagittal anorectoplasty (PSARP) has been the standard for management of children with high anorectal malformations (ARMs). Recently, there has been an increase in the use of laparoscopy in its management. We analyzed the outcomes of laparoscopically assisted anorectal pull-through (LAARP) compared to PSARP using a large inpatient database. Methods: Kids' Inpatient Database was analyzed for ARM (ICD-9-CM 751.2) between 1997 and 2012. Perineal fistulas and low/intermediate ARM were excluded. Propensity score (PS)-matched analyses were performed using 37 variables. Cases were weighted to provide national estimates. Results: Of the overall 29,106 cases, 7428 patients <2 years underwent surgical repair. LAARP was performed in 178 patients. Eighty-eight percent were male. Most were of Caucasian (n = 71; 45%), followed by Hispanic (n = 41; 26%) descent. Most were performed in 2009 and 2012 (n = 149; 83%). Most were covered by Medicaid (88; 49%), followed by private insurance (80; 45%). Median length of stay (LOS) was 4 (interquartile range = 3) days. The majority were performed in a children's hospital (n = 90; 88%). On PS-matched analysis, LAARP had shorter median LOS (4 [3]) compared to PSARP (6 [15]) days, P = .003. Rates of reoperation, wound infection, wound dehiscence, and mortality were unchanged between approaches. Cost was lower for LAARP (47,969 [49,450]) versus PSARP (56,110 [160,314]) U.S. dollar , P = .002, whereas total charges did not differ significantly. Conclusions: A minimal access approach to a complex procedure requires significant time and resources to be adopted as standard. PSARP is an important example, as increased availability of laparoscopy, and therefore, access to the procedure for patients will greatly affect resource utilization and recovery for the patient. As demonstrated, the LOS and cost is significantly lower for the LAARP procedure in comparison to the traditional approach. Future research will clarify boundaries to introducing the laparoscopic approach as a potential standard technique in the next decade.

Single-incision laparoscopic-assisted anorectoplasty for treating children with intermediate-type anorectal malformations and rectobulbar fistula: a comparative study

PURPOSE

Single-incision laparoscopic-assisted anorectoplasty (SILAARP) was compared to posterior sagittal anorectoplasty (PSARP) for treating intermediate-type anorectal malformations (ARMs) with rectobulbar fistula.

METHODS

Between December 2011 and January 2016, 48 children with intermediate-type ARMS were treated with SILAARP (n = 34) or PSARP (n = 14) in our centre. Data including demographics, complications, and long-term outcomes were retrospectively compared.

RESULTS

No significant difference was observed between both groups in terms of median operative time and complications. The length of postoperative hospital stay was shorter in the SILAARP group than in the PSARP group (6.15 ± 1.10 vs 9.64 ± 4.13 days; p = 0.008). After a mean follow-up of 59.38 ± 13.68 months, the rates of voluntary bowel movements, soiling, and constipation were similar in both groups. Anorectal manometry was performed in 15 and 7 children from the SILAARP and PSARP groups, respectively. Although there were no significant differences in the presence of rectoanal relaxation reflex and high-pressure-zone length, anal canal resting pressure was higher in the SILAARP group than in the PSARP group (33.35 ± 12.95 vs 23.06 ± 8.40 mmHg; p = 0.039).

CONCLUSIONS

Both SILAARP and PSARP seemed feasible and effective for treating intermediate-type ARMs with rectobulbar fistula in children. However, SILAARP significantly reduced the length of postoperative hospital stay and improved anal canal resting pressure.