- Email: [email protected]
Variability of the transition zone length in Hirschsprung disease
YJPSU-59409; No of Pages 4 Journal of Pediatric Surgery xxx (xxxx) xxx
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Variability of the transition zone length in Hirschsprung’s disease☆ Hemanshoo S Thakkar a, Simon Blackburn a, Joe Curry a, Paolo De Coppi a, Stefano Giuliani a, Neil Sebire b, Kate Cross a,⁎ a b
Department of Specialist Neonatal and Paediatric Surgery, Great Ormond Street Hospital for Children, London, UK Paediatric & Developmental Pathology, UCL Institute of Child Health, Great Ormond Street Hospital, London, UK
a r t i c l e
i n f o
Article history: Received 5 September 2019 Accepted 29 September 2019 Available online xxxx Key words: Hirschsprung’s disease Transition zone Frozen section Proximal donut
a b s t r a c t Background: Surgical management of Hirschsprung’s disease (HD) involves fully excising the transition zone (TZ). The literature suggests that resection of ≥5 cm of ganglionic bowel proximal to the aganglionic segment is sufficient. Our primary aim was to evaluate the lengths of the TZ in a cohort of consecutive patients with HD. We reviewed the impact this had on the need for revision surgery. We hypothesized that the TZ can be highly variable and may lead to a TZ pull-through when the proximal donut is not reviewed intraoperatively. Methods: A retrospective review was conducted for all patients undergoing primary pull-through surgery between January 2012 and September 2018. Data was collected on demographics, need for staged surgery, and complications following surgery. Results: Forty-eight patients were eligible for inclusion. 11/48 (23%) patients presented late (N 6 months). 27/48 (56%) patients needed a stoma prior to definitive surgery. The median age at pull-through was 6 months (1–84 months). The median TZ length was 1.7 cm (0.3–22.9 cm). 11/48 (23%) had a TZ N5 cm. 36/48 (75%) patients did not have intraoperative review of the donut resulting in three TZ pull-throughs. Conclusions: We would advocate circumferential intraoperative frozen section review of the proximal donut to minimize the risk of a TZ pull-through. Level of Evidence: Level III © 2019 Published by Elsevier Inc.
1. Background The surgical management of HD involves excision of at least part of the aganglionic bowel and the transition zone (TZ). Histologically, the transition zone is characterized by three main features; partial circumferential aganglionosis, myenteric hypoganglionosis and submucosal nerve hypertrophy [1]. Transitional zone pull-through has been cited as an important etiological factor in persistent post-operative obstructive symptoms [2]. A systematic review conducted over a 26-year period of patients who have undergone revision surgery identified abnormal histology on repeat rectal biopsy in nearly a 1/3 of cases, of which the large proportion of patients either had residual aganglionosis or evidence of a TZ pull-through [3]. The TZ has been reported in the literature to be limited to b5 cm bowel length [1]. However, intraoperatively determining the true segment of ganglionic bowel proximal to
☆ How this paper will improve care: Our results demonstrate the significant variability in the length of the TZ in HD. Circumferential intraoperative frozen section review of the proximal donut can help mitigate against a TZ pull-through in keeping with the latest APSA consensus statement. ⁎ Corresponding author at: Department of Specialist Neonatal & Paediatric Surgery, Great Ormond Street Hospital for Children, Great Ormond Street, , London WC1N 3JH, UK E-mail address: [email protected] (K. Cross).
the TZ can be difficult to identify if the bowel is not histologically examined in a circumferential fashion [2]. In our experience, the length of the TZ zone can be significantly longer than has been cited in the literature. 2. Methods A retrospective review was conducted for all patients with HD undergoing surgery between January 2012 and September 2018 at our institution. Any patients who had previously undergone a pull-through procedure elsewhere were excluded. Our preference has been to perform a single-stage pull-through where possible at the age of 3 months when diagnosed in the neonatal period. We do not routinely perform a contrast enema in our patients but use it as a diagnostic/therapeutic tool in cases which do not respond to washouts. The majority of surgeons within the department perform a Duhamel reconstruction. Intraoperative frozen section biopsies are sent in all cases, however not all surgeons also await a frozen section review of the proximal donut prior to completing the pull-through. If a frozen section review of the proximal donut is sought, the histopathologist will examine the specimen circumferentially en face. Within the histopathological department, all resected specimens are then reviewed with the length of the aganglionic bowel and transition zone formally reported. Further data was collected on patient demographics, age at presentation, need for
https://doi.org/10.1016/j.jpedsurg.2019.09.056 0022-3468/© 2019 Published by Elsevier Inc.
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
2
H.S. Thakkar et al. / Journal of Pediatric Surgery xxx (xxxx) xxx
Table 1 Patient demographics.
Table 3 Pre- and post-operative outcomes for patients as stratified by the TZ length
Demographics
Frequency (n=48)
Male Pre-term Syndromic Late presentation (N6 months) Stoma prior to pull-through surgery
36 (75%) 4 (8%) 10 (21%) 11 (23%) 27 (56%)
Table 2 Reasons for staged surgery. Clinical reason
Frequency (n=27)
Gross abdominal distension/failed washouts Late diagnosis (age N6 months) Dilated bowel noted at time of surgery – pull-through abandoned Perforation Failure to thrive Suspected hypoganglionosis at local hospital Unclear frozen-section histology at time of pull-through Fecaloma noted at time of surgery
15 (55%) 4 (15%) 3 (11%) 1(4%) 1 (4%) 1 (4%) 1 (4%) 1 (4%)
staged-surgery, and complications following surgery including the need for any revision surgery. Chi-squared test was used for statistical analysis with a p-value b 0.05 considered statistically significant. The study received institutional ethical approval (#2395). 3. Results 48 patients underwent primary pull-through surgery during the study period. The demographics for these patients are as summarized in Table 1. The median gestational age was 38 weeks (IQR 3). 27/48 (56%) patients needed a stoma prior to their definitive pull-through surgery (Table 2). The commonest reason for this was the presence of gross abdominal distension despite washouts. 15% of our patients presented after the age of 6 months and a further 21% were syndromic. The median age at pull-through was 6 months (1-84 months) with 44/48 (92%) of patients undergoing a Duhamel procedure.
Outcome
TZ length ≤5 cm (n=37)
TZ length N5cm (n=11)
p-Value
Pre-operative stoma TZ pull-through Need for any further surgical procedures Revision surgery
19/37 (51%) 1/37 (3%) 3/37 (8%)
8/11 (73%) 2/11 (18%) 1/11 (9%)
0.21 0.06 0.91
2/37 (5%)
2/11 (18%)
0.18
The median length of the TZ was 1.7 cm (0.3-22.9 cm) (Fig. 1). There was a positive trend between the length of aganglionosis and the TZ length but did not reach statistical significance. 11/48 (23%) of patients had a TZ length N 5cm (5.5-22.9 cm). Of these patients, 5/11 (45%) presented outside the neonatal period, 8/11 (72%) needed staged surgery and 3/11 (27%) have needed further surgery. Of these, one patient developed a rectal stricture requiring dilatations which has now resolved. Two patients have needed revision surgery (one for a rectal perforation following dilatation and one following TZ pull-through). The patient who had a TZ pull-through had intraoperative mid-sigmoid frozen section biopsy which was reported to be ganglionic without any hypertrophied nerves. There was no intraoperative frozen donut review. The proximal resection margin was formally then found to have ganglion cells with hypertrophied nerves. The TZ length was reported to be 5.5 cm and the length of aganglionosis was 6.0 cm. Two further patients in our study have also had a TZ-pull through. Neither of these patients had a frozen section review of the proximal donut. One patient underwent staged surgery and has had their stoma reversed. This patient remains clinically well and is under close follow-up. The second patient is currently symptomatic following closure of stoma with soiling and has had an episode of enterocolitis. This patient is awaiting further investigation with a biopsy and may need revision surgery. Overall when comparing patients who had a TZ length b5 cm with those above, there was no statistical difference between the need for staged-surgery, TZ pull-through, post-pull through surgery for complications or the need for revision surgery (Table 3). 12/48 (25%) patients had an intraoperative frozen section review of the proximal donut. Of these, three patients were found to have
25
TZ length (cms)
20
15
10 R² = 0.0698 5
0 0
5
10
15
20
25
30
Length of aganglionosis (cms)
Fig. 1. Relationship between length of aganglionosis and the TZ length
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
H.S. Thakkar et al. / Journal of Pediatric Surgery xxx (xxxx) xxx
3
Fig. 2. Technical completion of the pull-through procedures
evidence of transition zone in the proximal margin informing a moreproximal ganglionic pull-through. In the remaining 36/48 (75%) of cases which did not have frozen section review of the donut, three patients as described above underwent a TZ pull-through (p = 0.56), (Fig. 2). 4. Discussion Hirschsprung’s disease is characterized by the presence of submucosal and myenteric aganglionosis with nerve hypertrophy [1]. As per published literature, the male: female ratio of patients in our study was 4:1. In 2017, the British Association of Paediatric Surgeons (BAPS-CASS) reported national outcomes in the UK across a two-year cohort of 305 patients newly diagnosed with HD [4]. In keeping with our practice, rectal washouts were used as the initial management in 86% of patients with the remainder receiving a stoma as their initial treatment. In our series, over 50% of patients received a stoma prior to their definitive surgery which was higher than reported in this cohort of patients (36%). As encountered in our series, the commonest reason cited was due to a failure of washouts. However, 23% of patients in our series presented beyond 6 months of age which was the cut-off in the applied in the BAPS-CASS study. The majority of these patients in our cohort had a stoma fashioned prior to their definitive surgery. TZ pull-through has been cited as an important etiological factor in persistent post-operative obstructive symptoms as well as enterocolitis [2]. The incidence of TZ pull-through has been reported in the literature to be between 14-18% [5]. In a recently published series from New South Wales, Australia, the authors report their incidence of TZ pull-through to be 16% [5]. In two of their patients, ganglion cells were not present in the entire circumference of the proximal margin. In another series from the UK in 2003, the reported incidence of TZ pull-through was 19% [6]. Of the 18 children in this cohort who had a TZ pull-through, 61% of patients were re-admitted with one or more episodes of enterocolitis, 33% had problems with recurrent abdominal distension and 28% at the time of publication had undergone revision surgery. In our series, the TZ pull-through rate was much lower at 6% (three patients) all in patients who did not have intraoperative donut evaluation. One patient was symptomatic in the immediate postoperative period requiring a stoma. The other two patients remain under close follow-up. Histologically, in our three TZ cases, routine intraoperative frozen section biopsies were sent but not the full donut. Subsequently TZ was confirmed on the formal report with abnormal nerves identified at the proximal margin of the pull-through. The reliability of intraoperative frozen sections has been assessed in a study by Shayan et al. with a quoted discrepancy rate of 3% between the intraoperative and formal reports [7]. It is well-recognized that the distribution of ganglion cells in the TZ is uneven with a leading-edge of ganglion cells extending into aganglionic bowel [8]. In our series, the median
length of the TZ was 2.0 cm, however nearly a quarter of patients in our series had a length of N5 cm with a maximum of 22.9 cm. In view of the literature, general recommendations are to conduct the pull-through between at least 2–5 cm proximal to the distal most ganglionic biopsy [5]. However, when taking into account TZ lengths much greater than 5 cm, this idiom alone may not prevent a TZ pullthrough. These findings are also in accordance with another recently published series of patients in whom the TZ length was found to be extending up to 13 cm [10]. Boman et al. [9] have further conducted a semi-quantitative evaluation of the myenteric plexus at the proximal resection margin and identified significant variability in the percentage of the circumference of the muscularis propria that contained plexuses (30% - 95%). The authors of the Australian series [5] as well as Boman et al. [9] have both changed their institutional practice to integrate this into their practice. Within our institution, only a quarter of the cohort had frozen section review of the proximal donut. In our series, we avoided three cases of a TZ pull-through by conducting a frozen section review of the donut and a further three likely could have been avoided. This guidance for frozen donut evaluation is also in keeping with the most recent recommendations from the APSA Hirschsprung Disease Interest Group [11]. In conclusion, we have demonstrated the significant variability in the length of the TZ in HD and would mandate an intraoperative frozen section review of the proximal resection margin in all pull-through procedures to avoid a TZ pull-through. Author Contribution Study conception and design: Kate Cross Data acquisition: Hemanshoo Thakkar Analysis and data interpretation: Hemanshoo Thakkar, Kate Cross Drafting of the manuscript: Hemanshoo Thakkar, Simon Blackburn, Joe Curry, Paolo De Coppi, Stefano Giuliani, Neil Sebire, Kate Cross Critical revision: Simon Blackburn, Joe Curry, Paolo De Coppi, Stefano Giuliani, Neil Sebire, Kate Cross References [1] Kapur RP. Histology of the transition zone in Hirschsprung disease. Am J Surg Pathol 2016;40(12):1637–46. [2] Kapur RP, Kennedy AJ. Transitional zone pull through: surgical pathology considerations. Semin Pediatr Surg 2012;21:291–301. [3] Friedmacher F, Puri P. Residual aganglionosis after pull-through operation for Hirschsprung’s disease: a systematic review and meta-analysis. Pediatr Surg Int 2011;27:1053–7. [4] Bradnock TJ, Knight M, Kenny S, et al. The use of stomas in the early management of Hirschsprung disease: Findings of a national, prospective cohort study. J Pediatr Surg 2017;52(9):1451–7. [5] Ghosh DN, Liu Y, Cass DT, et al. Transition zone pull-through in Hirschsprung's disease: a tertiary hospital experience. ANZ J Surg 2017;87(10):780–3. [6] Farrugia MK, Alexander N, Clarke S, et al. Does transitional zone pull-through in Hirschsprung’s disease imply a poor prognosis? J Pediatr Surg 2003;38(12):1766–9. [7] Shayan K, Smith C, Langer JC, et al. Reliability of intraoperative frozen sections in the management of Hirschsprung's disease. J Pediatr Surg 2004;39(9):1345–8.
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
4
H.S. Thakkar et al. / Journal of Pediatric Surgery xxx (xxxx) xxx
[8] White FV, Langer JC. Circumferential distribution of ganglion cells in the transition zone of children with Hirschsprung disease. Pediatr Dev Pathol 2000;3(3):216–22. [9] Boman F, Sfeir R, Priso R, et al. Advantages of intraoperative semiquantitative evaluation of myenteric nervous plexuses in patients with Hirschsprung disease. J Pediatr Surg 2007;42(6):1089–94.
[10] Coyle D, O'Donnell AM, Tomuschat C, Gillick J, et al. The Extent of the Transition Zone in Hirschsprung's Disease. J Pediatr Surg. 2019 Apr 26. pii: S0022-3468(19)30314-8. [11] Veras LV, Arnold M, Avansino JR, Bove K et al. Guidelines for synoptic reporting of surgery and pathology in Hirschsprung disease. J Pediatr Surg. 2019 Mar 21. pii: S0022-3468(19)30212-X.
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Variability of the transition zone length in Hirschsprung’s disease☆ Hemanshoo S Thakkar a, Simon Blackburn a, Joe Curry a, Paolo De Coppi a, Stefano Giuliani a, Neil Sebire b, Kate Cross a,⁎ a b
Department of Specialist Neonatal and Paediatric Surgery, Great Ormond Street Hospital for Children, London, UK Paediatric & Developmental Pathology, UCL Institute of Child Health, Great Ormond Street Hospital, London, UK
a r t i c l e
i n f o
Article history: Received 5 September 2019 Accepted 29 September 2019 Available online xxxx Key words: Hirschsprung’s disease Transition zone Frozen section Proximal donut
a b s t r a c t Background: Surgical management of Hirschsprung’s disease (HD) involves fully excising the transition zone (TZ). The literature suggests that resection of ≥5 cm of ganglionic bowel proximal to the aganglionic segment is sufficient. Our primary aim was to evaluate the lengths of the TZ in a cohort of consecutive patients with HD. We reviewed the impact this had on the need for revision surgery. We hypothesized that the TZ can be highly variable and may lead to a TZ pull-through when the proximal donut is not reviewed intraoperatively. Methods: A retrospective review was conducted for all patients undergoing primary pull-through surgery between January 2012 and September 2018. Data was collected on demographics, need for staged surgery, and complications following surgery. Results: Forty-eight patients were eligible for inclusion. 11/48 (23%) patients presented late (N 6 months). 27/48 (56%) patients needed a stoma prior to definitive surgery. The median age at pull-through was 6 months (1–84 months). The median TZ length was 1.7 cm (0.3–22.9 cm). 11/48 (23%) had a TZ N5 cm. 36/48 (75%) patients did not have intraoperative review of the donut resulting in three TZ pull-throughs. Conclusions: We would advocate circumferential intraoperative frozen section review of the proximal donut to minimize the risk of a TZ pull-through. Level of Evidence: Level III © 2019 Published by Elsevier Inc.
1. Background The surgical management of HD involves excision of at least part of the aganglionic bowel and the transition zone (TZ). Histologically, the transition zone is characterized by three main features; partial circumferential aganglionosis, myenteric hypoganglionosis and submucosal nerve hypertrophy [1]. Transitional zone pull-through has been cited as an important etiological factor in persistent post-operative obstructive symptoms [2]. A systematic review conducted over a 26-year period of patients who have undergone revision surgery identified abnormal histology on repeat rectal biopsy in nearly a 1/3 of cases, of which the large proportion of patients either had residual aganglionosis or evidence of a TZ pull-through [3]. The TZ has been reported in the literature to be limited to b5 cm bowel length [1]. However, intraoperatively determining the true segment of ganglionic bowel proximal to
☆ How this paper will improve care: Our results demonstrate the significant variability in the length of the TZ in HD. Circumferential intraoperative frozen section review of the proximal donut can help mitigate against a TZ pull-through in keeping with the latest APSA consensus statement. ⁎ Corresponding author at: Department of Specialist Neonatal & Paediatric Surgery, Great Ormond Street Hospital for Children, Great Ormond Street, , London WC1N 3JH, UK E-mail address: [email protected] (K. Cross).
the TZ can be difficult to identify if the bowel is not histologically examined in a circumferential fashion [2]. In our experience, the length of the TZ zone can be significantly longer than has been cited in the literature. 2. Methods A retrospective review was conducted for all patients with HD undergoing surgery between January 2012 and September 2018 at our institution. Any patients who had previously undergone a pull-through procedure elsewhere were excluded. Our preference has been to perform a single-stage pull-through where possible at the age of 3 months when diagnosed in the neonatal period. We do not routinely perform a contrast enema in our patients but use it as a diagnostic/therapeutic tool in cases which do not respond to washouts. The majority of surgeons within the department perform a Duhamel reconstruction. Intraoperative frozen section biopsies are sent in all cases, however not all surgeons also await a frozen section review of the proximal donut prior to completing the pull-through. If a frozen section review of the proximal donut is sought, the histopathologist will examine the specimen circumferentially en face. Within the histopathological department, all resected specimens are then reviewed with the length of the aganglionic bowel and transition zone formally reported. Further data was collected on patient demographics, age at presentation, need for
https://doi.org/10.1016/j.jpedsurg.2019.09.056 0022-3468/© 2019 Published by Elsevier Inc.
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
2
H.S. Thakkar et al. / Journal of Pediatric Surgery xxx (xxxx) xxx
Table 1 Patient demographics.
Table 3 Pre- and post-operative outcomes for patients as stratified by the TZ length
Demographics
Frequency (n=48)
Male Pre-term Syndromic Late presentation (N6 months) Stoma prior to pull-through surgery
36 (75%) 4 (8%) 10 (21%) 11 (23%) 27 (56%)
Table 2 Reasons for staged surgery. Clinical reason
Frequency (n=27)
Gross abdominal distension/failed washouts Late diagnosis (age N6 months) Dilated bowel noted at time of surgery – pull-through abandoned Perforation Failure to thrive Suspected hypoganglionosis at local hospital Unclear frozen-section histology at time of pull-through Fecaloma noted at time of surgery
15 (55%) 4 (15%) 3 (11%) 1(4%) 1 (4%) 1 (4%) 1 (4%) 1 (4%)
staged-surgery, and complications following surgery including the need for any revision surgery. Chi-squared test was used for statistical analysis with a p-value b 0.05 considered statistically significant. The study received institutional ethical approval (#2395). 3. Results 48 patients underwent primary pull-through surgery during the study period. The demographics for these patients are as summarized in Table 1. The median gestational age was 38 weeks (IQR 3). 27/48 (56%) patients needed a stoma prior to their definitive pull-through surgery (Table 2). The commonest reason for this was the presence of gross abdominal distension despite washouts. 15% of our patients presented after the age of 6 months and a further 21% were syndromic. The median age at pull-through was 6 months (1-84 months) with 44/48 (92%) of patients undergoing a Duhamel procedure.
Outcome
TZ length ≤5 cm (n=37)
TZ length N5cm (n=11)
p-Value
Pre-operative stoma TZ pull-through Need for any further surgical procedures Revision surgery
19/37 (51%) 1/37 (3%) 3/37 (8%)
8/11 (73%) 2/11 (18%) 1/11 (9%)
0.21 0.06 0.91
2/37 (5%)
2/11 (18%)
0.18
The median length of the TZ was 1.7 cm (0.3-22.9 cm) (Fig. 1). There was a positive trend between the length of aganglionosis and the TZ length but did not reach statistical significance. 11/48 (23%) of patients had a TZ length N 5cm (5.5-22.9 cm). Of these patients, 5/11 (45%) presented outside the neonatal period, 8/11 (72%) needed staged surgery and 3/11 (27%) have needed further surgery. Of these, one patient developed a rectal stricture requiring dilatations which has now resolved. Two patients have needed revision surgery (one for a rectal perforation following dilatation and one following TZ pull-through). The patient who had a TZ pull-through had intraoperative mid-sigmoid frozen section biopsy which was reported to be ganglionic without any hypertrophied nerves. There was no intraoperative frozen donut review. The proximal resection margin was formally then found to have ganglion cells with hypertrophied nerves. The TZ length was reported to be 5.5 cm and the length of aganglionosis was 6.0 cm. Two further patients in our study have also had a TZ-pull through. Neither of these patients had a frozen section review of the proximal donut. One patient underwent staged surgery and has had their stoma reversed. This patient remains clinically well and is under close follow-up. The second patient is currently symptomatic following closure of stoma with soiling and has had an episode of enterocolitis. This patient is awaiting further investigation with a biopsy and may need revision surgery. Overall when comparing patients who had a TZ length b5 cm with those above, there was no statistical difference between the need for staged-surgery, TZ pull-through, post-pull through surgery for complications or the need for revision surgery (Table 3). 12/48 (25%) patients had an intraoperative frozen section review of the proximal donut. Of these, three patients were found to have
25
TZ length (cms)
20
15
10 R² = 0.0698 5
0 0
5
10
15
20
25
30
Length of aganglionosis (cms)
Fig. 1. Relationship between length of aganglionosis and the TZ length
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
H.S. Thakkar et al. / Journal of Pediatric Surgery xxx (xxxx) xxx
3
Fig. 2. Technical completion of the pull-through procedures
evidence of transition zone in the proximal margin informing a moreproximal ganglionic pull-through. In the remaining 36/48 (75%) of cases which did not have frozen section review of the donut, three patients as described above underwent a TZ pull-through (p = 0.56), (Fig. 2). 4. Discussion Hirschsprung’s disease is characterized by the presence of submucosal and myenteric aganglionosis with nerve hypertrophy [1]. As per published literature, the male: female ratio of patients in our study was 4:1. In 2017, the British Association of Paediatric Surgeons (BAPS-CASS) reported national outcomes in the UK across a two-year cohort of 305 patients newly diagnosed with HD [4]. In keeping with our practice, rectal washouts were used as the initial management in 86% of patients with the remainder receiving a stoma as their initial treatment. In our series, over 50% of patients received a stoma prior to their definitive surgery which was higher than reported in this cohort of patients (36%). As encountered in our series, the commonest reason cited was due to a failure of washouts. However, 23% of patients in our series presented beyond 6 months of age which was the cut-off in the applied in the BAPS-CASS study. The majority of these patients in our cohort had a stoma fashioned prior to their definitive surgery. TZ pull-through has been cited as an important etiological factor in persistent post-operative obstructive symptoms as well as enterocolitis [2]. The incidence of TZ pull-through has been reported in the literature to be between 14-18% [5]. In a recently published series from New South Wales, Australia, the authors report their incidence of TZ pull-through to be 16% [5]. In two of their patients, ganglion cells were not present in the entire circumference of the proximal margin. In another series from the UK in 2003, the reported incidence of TZ pull-through was 19% [6]. Of the 18 children in this cohort who had a TZ pull-through, 61% of patients were re-admitted with one or more episodes of enterocolitis, 33% had problems with recurrent abdominal distension and 28% at the time of publication had undergone revision surgery. In our series, the TZ pull-through rate was much lower at 6% (three patients) all in patients who did not have intraoperative donut evaluation. One patient was symptomatic in the immediate postoperative period requiring a stoma. The other two patients remain under close follow-up. Histologically, in our three TZ cases, routine intraoperative frozen section biopsies were sent but not the full donut. Subsequently TZ was confirmed on the formal report with abnormal nerves identified at the proximal margin of the pull-through. The reliability of intraoperative frozen sections has been assessed in a study by Shayan et al. with a quoted discrepancy rate of 3% between the intraoperative and formal reports [7]. It is well-recognized that the distribution of ganglion cells in the TZ is uneven with a leading-edge of ganglion cells extending into aganglionic bowel [8]. In our series, the median
length of the TZ was 2.0 cm, however nearly a quarter of patients in our series had a length of N5 cm with a maximum of 22.9 cm. In view of the literature, general recommendations are to conduct the pull-through between at least 2–5 cm proximal to the distal most ganglionic biopsy [5]. However, when taking into account TZ lengths much greater than 5 cm, this idiom alone may not prevent a TZ pullthrough. These findings are also in accordance with another recently published series of patients in whom the TZ length was found to be extending up to 13 cm [10]. Boman et al. [9] have further conducted a semi-quantitative evaluation of the myenteric plexus at the proximal resection margin and identified significant variability in the percentage of the circumference of the muscularis propria that contained plexuses (30% - 95%). The authors of the Australian series [5] as well as Boman et al. [9] have both changed their institutional practice to integrate this into their practice. Within our institution, only a quarter of the cohort had frozen section review of the proximal donut. In our series, we avoided three cases of a TZ pull-through by conducting a frozen section review of the donut and a further three likely could have been avoided. This guidance for frozen donut evaluation is also in keeping with the most recent recommendations from the APSA Hirschsprung Disease Interest Group [11]. In conclusion, we have demonstrated the significant variability in the length of the TZ in HD and would mandate an intraoperative frozen section review of the proximal resection margin in all pull-through procedures to avoid a TZ pull-through. Author Contribution Study conception and design: Kate Cross Data acquisition: Hemanshoo Thakkar Analysis and data interpretation: Hemanshoo Thakkar, Kate Cross Drafting of the manuscript: Hemanshoo Thakkar, Simon Blackburn, Joe Curry, Paolo De Coppi, Stefano Giuliani, Neil Sebire, Kate Cross Critical revision: Simon Blackburn, Joe Curry, Paolo De Coppi, Stefano Giuliani, Neil Sebire, Kate Cross References [1] Kapur RP. Histology of the transition zone in Hirschsprung disease. Am J Surg Pathol 2016;40(12):1637–46. [2] Kapur RP, Kennedy AJ. Transitional zone pull through: surgical pathology considerations. Semin Pediatr Surg 2012;21:291–301. [3] Friedmacher F, Puri P. Residual aganglionosis after pull-through operation for Hirschsprung’s disease: a systematic review and meta-analysis. Pediatr Surg Int 2011;27:1053–7. [4] Bradnock TJ, Knight M, Kenny S, et al. The use of stomas in the early management of Hirschsprung disease: Findings of a national, prospective cohort study. J Pediatr Surg 2017;52(9):1451–7. [5] Ghosh DN, Liu Y, Cass DT, et al. Transition zone pull-through in Hirschsprung's disease: a tertiary hospital experience. ANZ J Surg 2017;87(10):780–3. [6] Farrugia MK, Alexander N, Clarke S, et al. Does transitional zone pull-through in Hirschsprung’s disease imply a poor prognosis? J Pediatr Surg 2003;38(12):1766–9. [7] Shayan K, Smith C, Langer JC, et al. Reliability of intraoperative frozen sections in the management of Hirschsprung's disease. J Pediatr Surg 2004;39(9):1345–8.
Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056
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Please cite this article as: H.S. Thakkar, S. Blackburn, J. Curry, et al., Variability of the transition zone length in Hirschsprung’s disease, Journal of Pediatric Surgery, https://doi.org/10.1016/j.jpedsurg.2019.09.056