Journal of Indian Association of Pediatric Surgeons
Journal of Indian Association of Pediatric Surgeons
                                                   Official journal of the Indian Association of Pediatric Surgeons                           
Year : 2021  |  Volume : 26  |  Issue : 1  |  Page : 16--22

Optimism for the Single-stage Transanal Swenson in Neonates


Wesam Mohamed1, Mohamed I Elsawaf2, Aly I Shalaby1, Ahmed E Arafat1, Mahmoud M Marei1, Mohamed H Aboulfadl1, Sherif N Kaddah1, Gamal H El Tagy1, Khaled H K. Bahaaeldin1,  
1 Department of Pediatric Surgery, Cairo University Specialized Pediatric Hospital, Cairo, Egypt
2 Department of Pediatric Surgery, Tanta University, Tanta, Egypt

Correspondence Address:
Prof. Mohamed I Elsawaf
Department of Pediatric Surgery, Tanta University, Tanta
Egypt

Abstract

Background: Hirschsprung's disease (HD) has been traditionally treated from infancy onward and different techniques have been used including Swenson, Soave, and Duhamel procedures. The purpose of this study was to evaluate the transanal Swenson's procedure for classical rectosigmoid HD in neonates. Patient and Methods: This was a prospective study in which neonates diagnosed with HD were recruited from January 2017 to December 2018. Cases with a transition zone proximal to the midsigmoid were excluded. All patients underwent a transanal Swenson's procedure in the neonatal period using a unified protocol. Intraoperative course and postoperative outcomes such as leak, pelvic abscess, soiling, perianal excoriation, stricture, enterocolitis, and constipation were evaluated and all patients were followed for at least 6 months. Results: Twenty-three patients (17 males and 6 females) underwent transanal Swenson's procedure. The mean age was 22 ± 5.7 days. Follow-up ranged from 6 to 30 months. No anastomotic leak, retraction, or prolapse was reported. Mild perianal excoriations occurred early in 9 (39%) cases and all responded to medical treatment and disappeared before 2 months postoperatively. Stricture occurred in 2 (8%) patients, enterocolitis in 3 (13%), and constipation in 3 (13%). Conclusion: Transanal Swenson's procedure is feasible and can be performed safely in neonates with rectosigmoid HD with good short-term outcomes. Proper patient selection and standard protocol following fine procedural hall-marks and details are keys for optimal results and patient satisfaction.



How to cite this article:
Mohamed W, Elsawaf MI, Shalaby AI, Arafat AE, Marei MM, Aboulfadl MH, Kaddah SN, El Tagy GH, K. Bahaaeldin KH. Optimism for the Single-stage Transanal Swenson in Neonates.J Indian Assoc Pediatr Surg 2021;26:16-22


How to cite this URL:
Mohamed W, Elsawaf MI, Shalaby AI, Arafat AE, Marei MM, Aboulfadl MH, Kaddah SN, El Tagy GH, K. Bahaaeldin KH. Optimism for the Single-stage Transanal Swenson in Neonates. J Indian Assoc Pediatr Surg [serial online] 2021 [cited 2022 Oct 2 ];26:16-22
Available from: https://www.jiaps.com/text.asp?2021/26/1/16/306696


Full Text



 Introduction



The surgical treatment of Hirschsprung's disease (HD) has evolved from the historical three-stage procedure to a single-stage technique. Since then, multiple series reported its safety, efficacy, and feasibility in the management of HD in the neonatal period.[1],[2],[3],[4],[5],[6] Swenson and Bill,[7] Soave,[8] and Duhamel[9] are the most common procedures for HD. However, there is a heated debate about which technique gives the best short- and long-term outcomes.[10]

Although Soave and Duhamel procedures avoid the potential complications of Swenson, the retained aganglionic tissues may cause problems: muscular cuff complications in Soave and fecaloma formation in Duhamel.[11],[12] Over the past decades, continuous evolution and modifications of Soave's procedure were attempted mainly through shortening of the muscular cuff to avoid complications, by time cuff was as short as 2 cm to resemble Swenson's pullthrough. After the introduction of transanal Soave's pullthrough, the procedure become easier and complete excision of the aganglionic segment become feasible and reproducible. Hence, Swenson's-like pullthrough regained popularity and is gradually replacing Soave's because it offers complete excision of the pathology. Weinder and Waldhausen, in 2003, described the first transanal Swenson-like pullthrough for HD with promising preliminary results.[13] Based on their experience of full-thickness rectal dissection in anorectal malformations, Levitt et al. used the same approach and reported good short- and long-term outcomes.[10] The above experience favored our choice of the single-stage transanal Swenson's approach in neonates with rectosigmoid HD. We believe that optimization of the surgical approach and sticking to a specific protocol in diagnosis and treatment of neonatal HD improves the outcome.

The purpose of this study was therefore to evaluate the feasibility and short-term outcomes of this approach in neonatal age group.

 Patient and Methods



Neonates admitted to the surgical neonatal intensive care unit with a clinical picture of HD were recruited for this prospective study starting from January 2017. The protocol was approved by the research ethics committee. Written informed consent was obtained from all parents. Patients with a histological and a radiological diagnosis of rectosigmoid HD (transition zone distal to the midsigmoid) were included. Neonates with intestinal obstruction not relieved by conservative management, neonates weighing <2.5 kg, cases associated with severe respiratory or cardiac comorbidities, and cases with ill-defined transition zone were excluded. Patients' characteristics such as age, gender, history, clinical examination, and preoperative investigations were recorded.

The preoperative preparation, operative technique, and postoperative follow-up were standardized as possible. All neonates had water-soluble contrast enema once suspected to have HD looking for the confirmation of the diagnosis and detection of the transitional zone (TZ). All cases with TZ proximal to the midsigmoid colon or not clear were excluded from our study. Histological confirmation by mucosal rectal biopsy was obtained in all cases.

Preoperative preparation

Rectal washouts with saline 10 ml/kg three times daily the day before the surgery was done. Fasting and intravenous fluids 6 h were given preoperatively, then antibiotics administration in the form of third-generation cephalosporin (cefotaxime 50 mg/kg) and metronidazole 7.5 mg/kg at the induction of anesthesia.

Procedure

General anesthesia was given. The patient was first dilated using a Hegar dilator two sizes larger than the appropriate one for age. An appropriate size urethral catheter was fixed, and total body preparation was done, then the patient was placed prone with pelvis slightly elevated with a towel roll. Lone Star® retractor using neonatal size hooks was then applied. Frist, we applied the hooks to the junction between the skin and anoderm [Figure 1] and after exposure and identification of the dentate line, hooks were repositioned one centimeter above it assuming protection of the anal sphincter and the very important rectal mucosa for better continence outcome. Multiple circumferential 4/0 silk stay sutures were placed 1 cm above the pectinate zone to exert a uniform traction. A full-thickness rectal incision immediately below the stay sutures was then made using a fine diathermy needle with pure cut mood on law settings. Then, rectal dissection sticking to the rectal wall within Waldeyer's fascia for the preservation of urogenital autonomic nerves using monopolar diathermy needle [Figure 2] was continued till the peritoneal reflection. Peritoneum was then divided all around to enter the peritoneal cavity [Figure 3]. Then, we move proximally till reaching the TZ and completing devascularization at least 5 cm proximal to it. Either bipolar diathermy or suture ligation of the rectal blood vessels was used. Great care should be directed to avoid twist of the colon during devascularization. Full-thickness colonic biopsies were taken and sent for frozen section pathological examination every 5 cm till normoganglionic nondilated colon is reached, and then at this level, the distal colon was resected. The length of the resected segment was measured. The pulled-through colon was confirmed to be ganglionated, well vascularized, not twisted, and tension free before starting the anastomosis. A double-layer colorectal anastomosis with 4/0 absorbable interrupted sutures (Polyglactin 910) was constructed. The first layer is formed of 8 interrupted sutures placed between the seromuscular layer of the colon 1 cm above the resection margin and the opposite perirectal tissue [Figure 4]. Now, the hooks can be repositioned to expose the edge of rectal incision. Then, a second layer of multiple interrupted sutures is placed between the edge of the colon and the margin of rectal mucosa above the anal canal [Figure 5]. Intraoperative details and complications were recorded. A piece of Vaseline gauze soaked with povidone iodine 10% was then introduced into the neorectum. Postoperative care and follow-up: All patients were kept on intravenous fluids and antibiotics (cefotaxime 100 mg/kg/day and metronidazole 7.5 mg/kg/dose). Oral feeding was started on the 2nd postoperative day and patients were ready to discharge 48 h postoperatively unless otherwise specified by the pediatrician. Rectal irrigation regimen was started routinely on the 2nd postoperative day for 6 consecutive weeks: initially daily for 2 weeks, then every other day for the following 2 weeks, and finally every 3rd day for the last 2 weeks as described by De La Torre (personal communication with De la Torre). Discharge medication included ampicillin/clavulanic 30 mg/kg/day and oral metronidazole for 5 days.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}

Postoperative course, hospital stay, and complications were documented. The feasibility of the procedure was assessed regarding the colorectal dissection, colorectal anastomosis, intraoperative complications, and operative time. Dilatation was routinely started 2 weeks postoperatively: twice daily for 1 week, then once daily for 1 week, and every other day for 2 weeks using Hegar dilators #9 and gradually increasing to #12. Following this, the patient was reassessed by digital rectal examination to detect any stricture, and if any, dilatations were continued as indicated.

All patients were reviewed at 2 weeks, 6 weeks, 3 months, and 6 months' intervals in the outpatient clinic. They were evaluated for the following postoperative complications: soiling, perianal excoriation, stricture, enterocolitis, and constipation. The assessment included history taking, physical examination including digital rectal examination, and investigations as indicated if obstructive symptoms developed.

A high index of suspicion toward enterocolitis was kept and parents were advised to seek medical advice if the infant developed fever, abdominal distension, and foul-smelling explosive diarrhea. Parents were also trained on rectal dilatations and irrigation regimens if indicated. Enterocolitis was graded according to the clinical grading system.[14]

 Results



Twenty-three neonates with a definite histological and radiological diagnosis of rectosigmoid HD were included in this study: 17 (73%) males and 6 (27%) females. The mean age at operation was 22 ± 5.7 days (range: 14–30 days) and the mean weight was 3.2 ± 0.43 kg (range: 2.7–4 kg). Patients presented with delayed passage of meconium in 3 (13%) cases, lower GI obstruction in 19 (83%) cases, and enterocolitis in 1 (4%) case. Only one case (4%) had an associated Trisomy 21.

All cases underwent a single-stage transanal Swenson's pullthrough following the described protocol. The mean operative time was 106 ± 15 min (range, 80–135 min). Intraoperatively, there was no significant blood loss or visible pelvic organ injury. The resected colon length ranged from 17 to 30 cm (mean 22 ± 3.4 cm), while the aganglionic segment ranged from 11 to 20 cm (mean 17.6 ± 2.6 cm) [Figure 6]. The colorectal anastomosis was done proximal to the transition zone guided by frozen section, joining the nondilated normoganglionic colon to the rectal wall. The specimens were sent for histopathological evaluation of the surgical margin, which proved to be normoganglionic in all patients. Postoperatively, all patients had an uneventful course, passed stool on the 2nd postoperative day, and started oral feeding accordingly. The frequency of postoperative bowel motions ranged between 1 and 3/day (mean 1.9 ± 0.3).{Figure 6}

Postoperative hospital stay ranged from 3 to 4 days (mean, 3.1 ± 1 days). Follow-up period ranged from 6 to 30 months (median, 11 ± 4.6 months). No anastomotic leaks, retraction, prolapse, or pelvic abscesses were encountered. Mild perianal excoriations occurred early in 9 cases (39%) and all responded to medical treatment and disappeared before 2 months postoperatively. Two (8%) patients developed strictures: one responded to conservative management after 3 months of serial Hegar dilatations, while the other had a refractory stricture which required dilatation under anesthesia followed by topical application of mitomycin C at the stricture site and he finally responded adequately as well.

Enterocolitis occurred in three (13%) patients. The first patient had grade II enterocolitis, presented 2 weeks postoperatively, and was therefore readmitted. This baby was managed by intravenous fluids, antibiotics (amoxicillin/clavulanic acid, gentamycin, and metronidazole), and repeated rectal washouts. He was discharged after 5 days following cessation of the watery stools, resumption of oral feeding, and improvement of his general condition. The same patient had another attack of enterocolitis a month later, diagnosed as grade I, and was managed at home with daily rectal washouts and oral metronidazole with subsidence of symptoms in 48 h. The second patient presented 3 weeks postoperatively with grade II enterocolitis that also required hospitalization and was discharged after 4 days. The third patient presented 1 month postoperatively with grade I enterocolitis and was treated at home by frequent rectal washouts and oral metronidazole. His symptoms resolved after 3 days. These 3 cases were investigated 1 month after resolution of the attack by gastrografin enema to exclude anatomical causes for these enterocolitis attacks and revealed no strictures or twist.

Three (13%) patients developed constipation. None of them had a stricture on digital rectal examination or residual aganglionosis on redo rectal biopsy. The three patients responded to lactulose and Senna-based laxatives as a part of bowel management program.

 Discussion



Management of HD has evolved from staged[15] to single-stage procedures,[16] from abdominal to laparoscopic-assisted[17] or totally transanal approaches[18] and from delayed definitive management to early primary intervention in the neonatal period.[16] HD management started with Swenson's procedure in the fifties, then moved to Soave's, Duhamel's, and passed through lots of modifications, and finally transanal approach was introduced in 1998. Last decade, after Weidner and Waldhausen described transanal like Swenson's procedure,[13] the technique is regaining popularity because it follows the classical idea of removing the entire aganglionic bowel and at the same time easy, feasible, and importantly reproducible.

So et al. were the first to describe single-stage treatment for HD in neonates.[16] There are some concerns about neonatal management of HD, including anesthetic complications, physiological instability, and technical issues such as the delicate sphincter muscles and a narrow pelvis with the relatively small operative field. However, the great advancement of anesthesia,[1] neonatal intensive care units' facilities, and fine intraoperative technical considerations, including meticulous dissection, magnification, and the use of appropriate anal retractors (Lone Star® Cooper Surgical Inc., Trumbull, CT USA) have paved the way for successful neonatal management of HD.[19]

Despite concerns about technical difficulties, anatomical factors, and perioperative care, the definitive management of HD in neonates is now gaining acceptance among pediatric surgeons and many series have advocated the definitive treatment of HD in the neonatal period.[1],[2],[3],[4],[5],[6] Moreover, early management has been proposed to decrease the liability for obstructive attacks, enterocolitis, and their consequences of hospitalization and associated mortality and morbidity including stoma complications if the definitive treatment is delayed. In addition, hugely dilated colon in infants and children with thickened wall and mesentery warrants excessive traction over anal sphincter and makes transanal dissection and colorectal anastomosis somewhat technically difficult when compared to small-size caliber and thin-wall colon in neonates.[20] Shallow pelvis in neonates is also another technical factor that contributes to a shorter transanal dissection and consequently decreases mean operative time.[19]

We found this approach feasible in neonates as all surgical steps necessary for safe outcomes were fulfilled. Intraoperative complications mentioned in the literature such as urethral, vaginal, or bowel injuries[21],[22],[23] were not encountered in our series. In this study, the mean operating time and postoperative hospital stay compared favorably with other series[13],[21],[22],[23] and with series of transanal Soave's endorectal pullthrough.[24],[25] We think that prone position was of a great benefit as it offered more effective control of mesenteric vessels and under vision anterior dissection of the rectum off very important structures. In addition, the use of magnification, strict hemostasis, dissection intimately to the rectal wall to avoid pelvic nerve damage, and avoidance of overstretch of anal sphincter were critically important steps for the success of the procedure [Figure 1],[Figure 2],[Figure 3]. In a trial to optimize the transanal Swenson's procedure, we concluded that meticulously sticking to detailed protocol (preoperative preparation, operative steps, and postoperative care and follow-up) shortened the learning curve and to our minds was the most important key factor responsible for better results.

Anastomotic leak is a serious complication in the early postoperative period. Teitelbaum et al.[4] reported a leak rate of 2.6%, while Levitt et al.[10] reported two cases of anastomotic leak (3%), one of them being diagnosed with HD at the age of 5 years and the other at seven. Besides the delayed diagnosis, both patients had very dilated proximal bowel, which is usually not the case in neonates. In the current study, we had no anastomotic leaks or pelvic abscesses. Absence of hugely dilated colon and lack of size discrepancy in neonates were very important factors that allowed a perfectly constructed colorectal anastomosis. Furthermore, maintaining good vascularity of the pulled-through bowel, fashioning a tension-free double-layer anastomosis [Figure 4] and [Figure 5], meticulous hemostasis, fine technique, and a good general condition of the patient are all prerequisites to minimize anastomotic leaks.

Postoperative excoriations are usually due to frequent motions after surgery that may reach up to 6–10 per day and lack of adaptation of perianal skin to stool. This may normally occur early postoperatively or abnormally in incontinent cases. It can persist for a long time and be intractable or it may be mild and easily treated. In our study, we encountered only mild perianal excoriations occurred early in 9 (39%) neonates and all responded easily to medical treatment and disappeared before 2 months postoperatively. We may explain this in two points. First, we left 1 cm of intact rectal mucosa protected under the Lone Star retractor and avoided undue stretch of the anal sphincter which leads to somewhat stronger anal sphincter and less frequent motions (ranged between 1 and 3/day). Second, we applied strict rectal irrigations protocol starting from 2nd postoperative day and continued for 6 weeks (personal communication with De La Torre). These irrigations were very important factors in preventing postoperative Hirschsprung's Associated Entero-Colitis (HAEC) and lead to reduced exposure of the perianal skin to stools and almost prevented excoriations.

It is difficult to perfectly judge continence before the age of 3 years, but soiling may be considered as a bad prognostic factor for sphincter control. Soiling was reported variably from 13% to 45% after Swenson's operation.[26],[27] Unfortunately, one of the limitations in our study was short follow-up period ranged from 6 to 30 months (median, 11 ± 4.6). Despite this short follow-up, none of our patients developed soiling postoperatively. This was classically due to avoiding overstretching of the anal sphincters achieved by Lone Star retractor, and meticulous dissection, in addition to preserving the very critical anal canal mucosa which lead to better continence outcome.

In the current study, we faced strictures in 2 (8%) patients, while the reported incidence in the literature ranges from 7% to 22% using transanal Swenson's technique[21],[23] and from 4% to 22% using transanal Soave's one.[5],[24],[25] The predisposing factors for a stricture include a long muscular cuff, ischemia, anastomotic leak, and noncompliance to dilatation regimens.[28] One of the two patients who developed a stricture responded to dilatations, while the other had a refractory stricture which failed to respond to serial dilatations. This case was managed by dilatation under anesthesia, followed by topical application of mitomycin C at the stricture site. This recalcitrant stricture of this particular patient may be partly due to ischemia of the pulled-through colon and partly due to failure to comply with the dilatation regimen.

Enterocolitis is a common complication of HD that may occur pre- or postoperatively even in a perfectly done pullthrough. Three (13%) patients developed postoperative enterocolitis in the current study, which is comparable to reports by Weidner and Waldhausen[13] and Levitt et al.[10] who used the transanal Swenson's approach and reported an incidence of 13% and 14%, respectively. On the other hand, the rate of enterocolitis varies widely from 6%[24] to 42%[4] among reported series of endorectal pullthrough. None of the patients with enterocolitis in the current study had a stricture or residual aganglionosis. Two patients had grade II enterocolitis and required hospitalization for frequent rectal irrigations, intravenous fluids, and antibiotics. The third patient had grade I and responded to medical treatment at home in the form of rectal irrigations and oral metronidazole.

A younger age at diagnosis and anastomotic complications (e.g., stricture) were found to increase the risk of postoperative enterocolitis.[29],[30] These factors may be associated with immature intestinal mucosal immunity and fecal stasis, resulting in bacterial overgrowth and consequent enterocolitis. Marty et al. reported that postoperative rectal irrigation decreases the incidence of enterocolitis.[31] Accordingly, postoperative dilatation and irrigation regimens were adopted in the current study. The authors believe that both regimens in addition to the transanal Swenson's technique which leaves no mechanical obstructive factors such as a muscular cuff or rectal pouch may have contributed to decrease the incidence of postoperative enterocolitis in this study.

Constipation is also considered a common complication after surgery for HD. In the current study, constipation occurred in three (13%) patients. Weidner and Waldhausen[13] reported that out of fifteen infants, one (6.6%) suffered from poor emptying despite dilatation and therefore underwent posterior internal sphincter myectomy, while Levitt et al. reported a constipation rate of 32% (21 cases out of 67) across different ages.[10] A similarly high rate of 42% was reported by Teitelbaum et al.[4] The three patients who developed constipation in our study did not have a stricture or any residual aganglionosis and all responded well to laxatives (lactulose and Senna) as a part of bowel management program.

 Conclusion



Promising results of the current study encouraged the authors to conclude that transanal Swenson's procedure for neonates with rectosigmoid HD, who are adequately decompressed and without severe enterocolitis is feasible, reproducible and the results are comparable to those reported in literature. Optimization of Swenson's approach for HD management including proper patient selection, preoperative preparation, standard protocol following fine procedural hall-marks and details, and proper postoperative follow-up is the key for optimal results and patient satisfaction. To the best of our knowledge, this is the largest case series of this approach in neonates to date in the English literature. A longer follow-up period is required to evaluate the long-term outcomes.

Acknowledgment

The authors wish to thank Ashraf Elkholy, MD, Professor of Pediatric Surgery, Cairo University, for his valuable insight in reviewing the manuscript.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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