doi: 10.56294/saludcyt2023576

ORIGINAL

Resection of the extravertebral portion of the filum terminale with posterior internal sphincterotomy, a surgical technique for managing chronic constipation and encopresis in children

Resección de la porción extravertebral del filum terminale con esfinterotomía interna posterior, una técnica quirúrgica para el tratamiento del estreñimiento crónico y la encopresis en niños

Freddy Alexander Aldaz Vallejo¹ *, Victor Sebastian Encalada Vasconez² *, Johanna Mosquera Moscoso² *, Jennifer Carolina Martínez³ *, Pablo Javier Castillo Herrera⁴ *

¹Baca Ortiz Hospital, Specialist in Pediatric Surgery. Quito, Ecuador.

²One Health Research Group, Faculty of Medicine, Universidad de las Américas. Quito, Ecuador.

³Saint-Petersburg State Pediatric Medical University, Specialist in Pediatric Surgery, Saint- Petersburg, Russia.

⁴Trauma- Hospital, Specialist in Pediatric Surgery, El Oro, Ecuador.

Cite as: Aldaz Vallejo FA, Encalada Vasconez VS, Mosquera Moscoso J, Martínez JC, Castillo Herrera PJ. Resección de la porción extravertebral del filum terminale con esfinterotomía interna posterior, una técnica quirúrgica para el tratamiento del estreñimiento crónico y la encopresis en niños. Salud, Ciencia y Tecnología. 2023; 3:576. https://doi.org/10.56294/saludcyt2023576

Received: 03-07-2023                           Revised: 11-08-2023                           Accepted: 24-09-2023                         Published: 25-09-2023

Editor: Dra. Nairobi Hernández Bridón

ABSTRACT

Background: constipation is a frequent digestive complaint in children and can be refractory to treatment in approximately 30 % of patients. Etiologies that are linked to this pathology include rectal hyporeflexia, achalasia of the internal anal sphincter, and neurological disorders such as tight filum terminale syndrome. For these conditions, the resection of the extra vertebral portion of the filum terminale and posterior internal sphincterotomy has shown potential benefits for management.

Methods: we conducted a cross-sectional descriptive study between 2020 and 2021. We collected data from 219 children’s medical records at Saint Petersburg State Pediatric Hospital, Russia, that fulfilled the diagnostic criteria and were managed surgically. We analyze their demographic characteristics and clinical outcomes.

Results: we found that 83,6 % (n=183) of participants showed improvement, while 16,4 % (n=36) experienced no improvement or complications. Patients in the 16-17 age group had the highest proportion of lack of improvement or complications, with 12,8 % and the 1-5 age group exhibited a 100 % improvement rate. Male patients exhibited a decreased probability of experiencing complications in the postoperative period.

Conclusion: resection of the extravertebral portion of the filum terminale with posterior internal sphincterotomy has shown potential benefits in managing chronic constipation and encopresis in pediatric patients. However, further research is warranted to investigate the benefits and risks of this surgical technique.

Keywords: Chronic Constipation; Tight Filum Terminale Syndrome; Encopresis.

RESUMEN

Antecedentes: el estreñimiento es una dolencia digestiva frecuente en los niños y puede ser refractario al tratamiento en aproximadamente el 30 % de los pacientes. Entre las etiologías relacionadas con esta patología se encuentran la hiporreflexia rectal, la acalasia del esfínter anal interno y trastornos neurológicos como el síndrome del filum terminale tenso. Para estas afecciones, la resección de la porción extravertebral del filum terminale y la esfinterotomía interna posterior han mostrado beneficios potenciales para su manejo.

Métodos: realizamos un estudio descriptivo transversal entre 2020 y 2021. Recopilamos datos de 219 historias clínicas de niños en el Hospital Pediátrico Estatal de San Petersburgo, Rusia, que cumplían los criterios diagnósticos y fueron manejados quirúrgicamente. Analizamos sus características demográficas y resultados clínicos.

Resultados: encontramos que el 83,6 % (n=183) de los participantes mostraron mejoría, mientras que el 16,4 % (n=36) no experimentaron mejoría ni complicaciones. Los pacientes del grupo de edad de 16-17 años presentaron la mayor proporción de ausencia de mejoría o complicaciones, con un 12,8 %, y el grupo de edad de 1-5 años exhibió una tasa de mejoría del 100 %. Los pacientes varones mostraron una menor probabilidad de experimentar complicaciones en el postoperatorio.

Conclusiones: la resección de la porción extravertebral del filum terminale con esfinterotomía interna posterior ha mostrado beneficios potenciales en el manejo del estreñimiento crónico y la encopresis en pacientes pediátricos. Sin embargo, es necesario seguir investigando los beneficios y riesgos de esta técnica quirúrgica.

Palabras clave: Estreñimiento Crónico; Síndrome del Filum Terminal Estrecho; Encopresis.

INTRODUCTION

Constipation is a frequent digestive complaint in the pediatric population, with a wide prevalence ranging from 0,7 % to 29,6 %.⁽¹⁾ Research findings have shown that over 40 % of pediatricians' office visits are attributed to this complaint, making it challenging for physicians to face this condition in their daily practice.⁽²⁾ Effective management depends on many factors, including a correct initial assessment, particularly when determining the cause.⁽³⁾ Chronic refractory constipation poses a challenge for approximately 30 % of patients experiencing constipation.⁽⁴⁾ It can be linked to various underlying or coexisting conditions, with poor treatment compliance being a common factor. Additionally, conditions such as Hirschsprung's disease, celiac disease, cow milk allergy, primary hyperparathyroidism, and connective tissue disorders may be associated.⁽⁴⁾ Rectal hyporeflexia, resulting from structural abnormalities affecting rectal innervation in the parasympathetic center of the spinal cord, can also contribute to these etiologies.⁽⁵⁾ Another contributing factor is achalasia of the internal anal sphincter, where the lack of parasympathetic innervation at the internal anal sphincter hinders proper emptying during defecation.^(6,7) Additionally, neurological disorders such as Tight filum terminale syndrome can result in spinal flexion with a rigid filum terminale, stretching the nerves that innervate the rectum and bladder. This can lead to ischemia, causing degeneration of nerve elements and reduced conduction of nerve impulses.^(8,9) In contrast to chronic constipation, encopresis is a disorder characterized by involuntary stool loss caused by a stricture at the internal anal sphincter. The prevalence of encopresis varies across different stages of childhood, with higher rates observed among preschoolers, estimated to be around 1-3 %.⁽¹⁰⁾

In the case of chronic constipation and encopresis, a surgical procedure that aims to resect the extravertebral portion of the filum terminale has shown potential for management.^(11,12,13) This procedure objective is to release the tension exerted on the sacral plexus in the parasympathetic pathway (S2-S4).^(8,14) Additionally, a posterior internal sphincterotomy is performed to alleviate the narrowness of the anal canal while preserving structures important for anal continence.

A surgical technique based on the patent issued by the Russian Federation, known as "Method of surgical treatment of chronic constipation and encopresis in children" (2019), number 2717216, developed by Dr. Kolesnikova N. G., Dr. Komissarov I. A., and Dr. Kovalev F. S, has shown potential benefits for managing chronic constipation and encopresis, demonstrating promising outcomes in treatment.⁽¹⁵⁾

METHODS

We conducted a cross-sectional descriptive study between 2020 and 2021. Prior to obtaining authorization and informed consent from parents or legal representatives, we collected data from 219 children's medical records at Saint Petersburg State Pediatric Hospital, Russia to analyze their demographic characteristics and clinical outcomes. We selected patients who met the inclusion criteria and were diagnosed with either chronic constipation refractory to treatment or encopresis. The causes of their chronic constipation were later subdivided into rectal hyporeflexia, achalasia of the internal anal sphincter, and tight filum terminale syndrome. They also fulfilled the criteria for surgical management and underwent surgical treatment involving resection of the extravertebral portion of the filum terminale, posterior internal sphincterotomy, and a combination of both. Patients were followed during a 6-month window. We categorized them based on their clinical outcomes and gastrointestinal transit tests. We observed two groups: patients who showed improvement and those who did not. Additionally, any complications that arose during this period were monitored and recorded. We utilized Microsoft Office™ Excel to collect the data, and the statistical analysis was performed using STATA version 17. The data analysis involved chi-square tests and logistic regression.

RESULTS

The data analysis involved 219 patients, with females accounting for 58,0 % (n=127) and males representing 42,0 % (n=92) of the sample. The age distribution revealed the highest prevalence in the 1-5 years age group (39,3 %, n=86), followed by the 6-10 years group (34,2 %, n=75), 11-15 years group (11,0 %, n=24), and 16-17 years group (15,5 %, n=34). The most prevalent condition observed was Tight filum terminale syndrome, and neurogenic hyporeflective dysfunction of the rectum collectively accounting for 43,8 % (n=96) of all cases, followed by achalasia of the internal anal sphincter, and encopresis with 35,6 % (n=78) and 20,5 % (n=45) respectively. Statistical analysis indicated no significant associations between age groups and diagnoses (p=0,105). Likewise, no notable gender-based differences were found in the distribution of diagnoses (p=0,623) table 1.

Table 1. Chi-square tests for diagnostic categories by age and gender
Characteristics	Total n (%)	Diagnosis			p-value Chi2*
		Achalasia of the internal anal sphincter n (%)	Encopresis n (%)	Tight Filum Terminale Syndrome n (%)
Age
1 - 5	86 (39,3)	21 (24,4)	23 (26,7)	42 (48,8)	0,105
6 - 10	75 (34,2)	32 (42,7)	11 (14,7)	32 (42,7)
11 - 15	24 (11,0)	12 (50,0)	3 (12,5)	9 (37,5)
16 - 17	34 (15,5)	13 (38,2)	8 (23,5)	13 (38,2)
Gender
Male	92 (42,0)	26 (28,3)	21 (22,8)	45 (48,9)	0,623
Female	127 (58,0)	52 (40,9)	24 (18,9)	51 (40,2)
Total	219 (100,0)	78 (35,6)	45 (20,5)	96 (43,8)
Note. (*) Chi-square test with statistical significance at <0,05.

The most frequent surgical procedure performed was resection of the extravertebral portion of the filum terminale with posterior internal sphincterotomy accounting for 53,4 % (n=117) of cases. Posterior internal sphincterotomy was performed in 21,0 % (n=46) of cases, while resection of the extravertebral portion of the filum terminale, was observed in 25,6 % (n=56) of cases. Statistical analysis using Chi-square tests revealed a significant association between age groups and surgical procedures (p<0,01). The highest prevalence of extravertebral resection of the filum terminale was found in the 1-5 age group (64,0 %, n=71), while the combination procedure was more common in the 16-17 age group (42,9 %, n=15).

No significant gender-based differences were found in the distribution of surgical procedures (p=0,164). Both males and females underwent procedures 1 and 2 to a similar extent table 2.

Table 2. Chi-square tests for surgical procedures by age and gender
Characteristics	Total n (%)	Surgical Procedures			p-value Chi2*
		1. Extravertebral Resection of the Terminal Filum n (%)	2. Posterior internal sphincterotomy n (%)	3. Extravertebral Resection of the Terminal Filum + Posterior internal sphincterotomy of rigid terminal filum (%)
Age
1 - 5	111 (50,7)	29 (26,1)	11 (9,9)	71 (64,0)	<0,01
6 - 10	43 (19,6)	10 (23,3)	13 (30,2)	20 (46,5)
11 - 15	30 (13,7)	9 (30,0)	10 (33,3)	11 (36,7)
16 - 17	35 (16,0)	8 (22,9)	12 (34,3)	15 (42,9)
Gender
Male	117 (53,4)	30 (25,6)	30 (25,6)	57 (48,7)	0,164
Female	102 (46,6)	26 (25,5)	16 (15,7)	60 (58,8)
Total	219 (100,0)	56 (25,6)	46 (21,0)	117 (53,4)
Note. (*) Chi-square test with statistical significance at <0,05.

From our findings on clinical outcomes, 83,6 % (n=183) of participants showed improvement, while 16,4 % (n=36) experienced no improvement or complications. We established a significant link between age groups and clinical outcomes (p<0,01). Notably, the 16-17 age group had the highest proportion of patients with no improvement or complications at 12,8 % (n=5). Conversely, the 1-5 age group exhibited a 100 % improvement rate (n=98).

Table 3. Chi-square tests and Odds Ratio for surgical outcomes by age and gender
Characteristics	Total n (%)	Results		p-value Chi2*
		No improvement And / Or Complications n (%)	With improvement n (%)
Age
1 - 5	98 (44,7)	0 (0,0)	98 (100,0)	<0,01
6 - 10	73 (33,3)	2 (2,7)	71 (97,3)
11 - 15	9 (4,1)	0 (0,0)	9 (100,0)
16 - 17	39 (17,8)	34 (87,2)	5 (12,8)
Gender
Male	113 (51,6)	17 (15,0)	96 (85,0)	0,565
Female	106 (48,4)	19 (17,9)	87 (82,1)
Total	219 (100,0)	36 (16,4)	183 (83,6)
Note. (*) Chi-square test with statistical significance at <0,05.

The odds ratio analysis reveals that males have a protective factor compared to females, indicating a higher probability of not experiencing complications. Similarly, patients aged 6-10 years have a protective factor. Patients diagnosed with encopresis have a higher probability of postoperative complications compared to other diagnoses. Resection of the extravertebral portion of the filum terminale alone has the highest risk, with an odds ratio of 12,60, of postoperative complications.

The logistic regression model employed in this study demonstrated statistical significance, with the Maximum Likelihood statistic (LR Chi2 = 115,79) surpassing the threshold of 3 and a p-value of less than 0,05. In terms of the impact of variables, gender was a significant factor. Male patients exhibited a decreased probability of experiencing complications in the postoperative period (-14,67), suggesting a protective effect compared to females. Age also played a role, with patients aged 6 to 10 years showing reduced chances of complications (-58,18). Diagnoses of encopresis were associated with a higher probability (67,57) of lack of improvement or complications, emphasizing the challenges faced by patients with this diagnosis.

Regarding surgical procedures, Resection of the extravertebral portion of the filum terminale alone and posterior internal sphincterotomy was found to have a higher incidence of poor improvement or complications.

DISCUSSION

Resection of the filum terminale has been used to treat various conditions, including occult tight filum terminale syndrome, part of the tethered cord syndrome.⁽¹⁶⁾ Patients with this syndrome can exhibit a range of clinical manifestations, such as sensory-motor disturbances and parasympathetic instability leading to fecal incontinence, chronic constipation, and bladder instability.⁽¹⁶⁾ Sectioning the rigid filum terminale has shown benefits for patients experiencing fecal incontinence and chronic constipation.⁽¹⁷⁾ A study by Wehby et al. demonstrated that this procedure resolved fecal incontinence in 56 % of patients and showed improvement in 41 % of those with tight filum terminale syndrome and bowel disturbances.^(17,18,19) Similarly, our results indicate an overall improvement in most patients (83,6 %) after a 6-month follow-up period. While these findings are promising, further research is necessary to determine the efficacy, risks, and long-term outcomes of this procedure. There is limited scientific information available regarding the use of this procedure alone for the treatment of chronic refractory constipation. Therefore, caution and a thorough evaluation of patients who may benefit from this procedure are recommended, especially in the pediatric population. Currently, there is no clear indication for surgical management in cases of chronic constipation, and careful consideration is needed before proceeding with this intervention.

CONCLUSION

We observed a potential benefit in patients who underwent the resection of the extravertebral portion of the filum terminale with posterior internal sphincterotomy for the management of chronic constipation and encopresis in the pediatric population. The majority of patients experienced improvement after the procedure, but we found a relationship between minimal improvement and specific diagnoses before the surgery, such as encopresis.

Age and gender play significant roles in the outcomes, with younger age groups, particularly the 1-5 year group, showing higher improvement rates than other age groups. Early detection can play a role in improving management outcomes. On the other hand, gender influenced the results, with males having a lower likelihood of postoperative complications than females.

Furthermore, the choice of intervention affected clinical results. Notably, extravertebral resection of the filum terminale with posterior internal sphincterotomy was the most frequently performed procedure with better outcomes. However, further research is necessary to explore this procedure's effectiveness and potential risks.

Given these findings, a multidisciplinary approach is needed to manage chronic constipation refractory to treatment and encopresis, considering individual patient characteristics, including age, gender, and specific diagnoses. Additionally, further research is warranted to investigate the benefits and risks of this surgical technique, which may contribute to beneficial outcomes in children.

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CONSENT

The respective authorizations were obtained to carry out this work.

FINANCING

There is no funding for this work.

Conflict of interests

The authors declare that there is no conflict of interest.

AUTHORSHIP CONTRIBUTION

Conceptualization: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Data curation: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Formal analysis: Victor Sebastian Encalada Vasconez.

Research: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez, Johanna Mosquera Moscoso, Jennifer Carolina Martìnez, Pablo Javier Castillo Herrera.

Methodology: Victor Sebastian Encalada Vasconez.

Project administration: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Supervision: Victor Sebastian Encalada Vasconez.

Validation: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Writing – original draft: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Writing – review and editing: Freddy Alexander Aldaz Vallejo, Victor Sebastian Encalada Vasconez.

Supplementary Material 1. Logistic regression estimated model

Supplementary Material 2. Matrix of partial regression coefficients (betas) ODDS