INTRODUCTION

Simulation based training, which is hypothesized to increase skill proficiency among trainees, is currently gaining popularity in pediatric surgical training. High-fidelity simulators are expensive and not easily replicable in low to middle income countries; thus, the use of low-fidelity simulators are being suggested. This type of educational technique may have a role in complex procedures such as pull-through procedure among patients with Hirschsprung's disease. This study aimed to ascertain the development and associated validity of low-fidelity simulators for transanal pull-through among pediatric patients.

This is a validation study of a low-fidelity simulator for transanal pullthrough in pediatric surgery. The model was assembled by carefully harvesting the anus, colon and rectum from a pig cadaver, ensuring the tissues remained intact including the perianal skin. These tissues were then mounted onto a specially designed basket that simulates the human pelvic cavity. The prototype model underwent initial testing to ensure anatomical accuracy and durability. A panel of five pediatric surgeons were tapped for content validation.

The overall validity index of the simulator was 1.00 which was high. All panel experts agreed on the anatomical realism, educational value, and alignment with training objectives. Some positive feedback on its use included its ability to accurately simulate the surgical procedure and its potential to reduce the learning curve for trainees. Another feedback is that it can help clinicians feel more prepared and comfortable when performing the procedure on actual patients after practicing on the simulator. No negative feedback were reported.

The study showed that the use of an animal simulator for practicing transanal pullthrough in pediatric surgery is feasible and valid. This model has the potential to be adapted for educational purposes and hands-on training before doing actual case surgeries. The realistic anatomy and tactile feedback provided by the simulator can help trainees improve their skills and confidence in performing transanal pullthrough.

Transanal bowel evisceration is a rare, life-threatening condition requiring urgent surgical intervention, with approximately 100 cases documented globally since 1827. While research predominantly addresses spontaneous cases, traumatic occurrences—often associated with stab wounds—remain underreported. The prevalence of traumatic small bowel evisceration is low, ranging from 0.2-1% worldwide, with no documented studies from Northern Luzon or the entire Philippines. Prompt diagnosis and immediate surgical management are essential to prevent serious complications, underscoring the importance of timely intervention for a successful outcome.

This is a rare case of small bowel evisceration secondary to traumatic rectal perforation. A 56-year-old male presented with intestinal protrusion through the anus, illustrating a rare instance of transanal small bowel evisceration. The patient's case provides important insights into the diagnosis and treatment of this uncommon condition.

Early detection was crucial for managing the transanal evisceration of the small bowel, a rare and life-threatening emergency, as timely surgical intervention is essential to prevent severe complications. This case underscores the importance of clinical awareness and prompt diagnosis, particularly given the rarity of traumatic transanal evisceration, to enhance patient outcomes.

OBJECTIVES: To investigate the characteristics and clinical significance of anorectal manometry measurements in children with tethered cord syndrome (TCS) before and after surgery. METHODS: A retrospective study was conducted on 44 children with TCS treated at the Children's Hospital of Zhejiang University School of Medicine from January 2022 to September 2023. These patients were divided into effective subgroup (n=34) and non-effective subgroup (n=10) based on postoperative symptom improvement. Additionally, 34 children with functional constipation were selected as a control group. Baseline data and manometry measurements were compared between the preoperative TCS group and the control group, as well as between the non-effective and effective subgroups. RESULTS: The TCS group had lower short contraction time and defecation relaxation rate compared to the control group (P<0.05), while defecation residual pressure and maximum rectal tolerable threshold were higher than the control group (P<0.05). The length of the anal canal in the high-pressure zone in the effective subgroup was greater postoperatively than preoperatively (P<0.05), and the initial rectal sensation threshold decreased postoperatively (P<0.05). The non-effective subgroup had lower preoperative maximum rectal expulsion pressure compared to the effective subgroup (P<0.05). Postoperative rectal anal inhibition reflex values in the effective subgroup were higher than those in the non-effective subgroup (P<0.05). CONCLUSIONS There are some differences in anorectal dynamics between children with TCS and those with functional constipation. Maximum rectal expulsion pressure may be a key predictor of surgical outcomes. Surgery can alter certain defecation functions in some children.
Humans ; Male ; Anal Canal/physiopathology* ; Female ; Rectum/physiopathology* ; Child ; Child, Preschool ; Retrospective Studies ; Manometry ; Neural Tube Defects/physiopathology* ; Infant ; Defecation ; Adolescent ; Constipation/physiopathology* ; Clinical Relevance

Tianhe procedure^® is a functional sphincter-preserving surgical approach developed for rectal cancer patients following radiotherapy. This technique involves extended proximal resection of the colon beyond the pelvic cavity, followed by anastomosis of the non-irradiated proximal colon to the distal rectum or anal canal. This strategy aims to reduce the incidence of anastomotic complications and postoperative bowel dysfunction. However, there is currently a lack of standardized practice guideline for implementing Tianhe procedure^® in China. Therefore, the Chinese Radiation Intestinal Injury Research Group, the Colorectal Surgery Group of Surgery Branch of the Chinese Medical Association, the Anorectal Branch of Chinese Medical Doctor Association, the Colorectal Cancer Committee of the Chinese Medical Doctor Association, and the Colorectal Cancer Committee of China Anti-cancer Association, and the Gastrointestinal Surgical Branch of Guangdong Medical Doctor Association, have jointly convened a panel of national experts to discuss and establish this standardized surgical procedure. This standard, based on the latest evidence from literature, research advancements, and expert experience, focuses on key aspects of the Tianhe procedure^®, including its precise definition, indications, critical procedural steps, postoperative complications, and functional rehabilitation strategies. It aims to promote standardized implementation and broader clinical adoption of this innovative surgical technique.
Humans ; Rectal Neoplasms/radiotherapy* ; Anal Canal/surgery* ; Anastomosis, Surgical/methods* ; Organ Sparing Treatments/methods* ; Rectum/surgery* ; Postoperative Complications/prevention & control* ; Digestive System Surgical Procedures/methods*

The modified Bacon procedure is a staged, sphincter-preserving surgical technique for low rectal tumors, which involves transanal or transabdominal division of the tumor, extraction of the specimen via the anus or abdomen, exteriorization and fixation of the proximal colon through the anus, followed by a second-stage resection of the exteriorized colon to restore intestinal continuity. This approach offers advantages such as a reduced risk of anastomotic leakage and operational safety. However, several clinical aspects lack consensus, including indications for the procedure, the optimal length of the exteriorized colon, methods of anal fixation, and the timing of the second-stage resection. To address these issues, the Colorectal Cancer Committee of the Chinese Medical Doctor Association, the Colorectal Cancer Committee of China Anti-Cancer Association, and the NOSES Committee of China Anti-Cancer Association jointly initiated a collaborative effort to convene experts in the field. Through discussions, 10 key clinical questions were identified, and based on a systematic review of relevant domestic and international clinical studies combined with expert opinions, 13 recommendations were formulated. These recommendations cover indications, contraindications, technical details, surgical complications, functional outcomes related to anal function, and oncological efficacy of the modified Bacon procedure. This consensus aims to provide guidance for the clinical practice of the modified Bacon procedure in China, thereby promoting its standardized and evidence-based implementation.
Humans ; Rectal Neoplasms/surgery* ; Consensus ; Anal Canal/surgery*

Intersphincteric resection (ISR) is the ultimate sphincter-preserving surgical technique for low rectal cancer. To promote the standardized implementation of ISR, this review discusses the important issues regarding the clinical application of ISR with reference to the latest Chinese expert consensus on ISR. In terms of ISR-related pelvic anatomy of the rectum/anal canal, hiatal ligament is not identical with the anococcygeal ligament. At the level where the rectourethralis muscle continuously extends to the posteroinferior area of the membranous urethra from the rectum, the neurovascular bundle is identified between the posterior edge of rectourethralis muscle and the anterior edge of the longitudinal muscle of the rectum. This knowledge is crucial to detect the anterior dissection plane during ISR at the levator hiatus level. The indication criteria for ISR included: (1) stage I early low rectal cancer; (2) stage II-III low rectal cancer undergoing neoadjuvant treatment, and supra-anal tumors and juxta-anal tumors of stage ycT3NxM0, or intra-anal tumors of stage ycT2NxM0. However, signet ring cell carcinoma, mucinous adenocarcinoma and undifferentiated carcinoma should be contraindicated to ISR. For locally advanced low rectal cancer (especially anteriorly located tumor), neoadjuvant treatment should be carried out in a standardized manner. However, it should be recognized that neoadjuvant chemoradiotherapy was a risk factor for poor anal function after ISR. For surgical approaches for ISR, including transanal, transabdominal, and transanal transabdominal approaches, the choice should be based on oncological safety and functional consequences. While ensuring the negative margin, maximal preservation of rectal walls and anal canal contributs to better postoperative anorectal function. Careful attention must be paid to complications regarding ISR, with special focus on the anastomotic complications. The incidence of low anterior resection syndrome (LARS) was higher than 40%. However, this issue is often neglected by clinicians. Thus, management and rehabilitation strategies for LARS with longer follow-ups were required.
Humans ; Rectal Neoplasms/pathology* ; Postoperative Complications ; Laparoscopy/methods* ; Anal Canal/pathology* ; Anus Neoplasms/pathology* ; Anus Diseases/surgery* ; Low Anterior Resection Syndrome ; Carcinoma, Signet Ring Cell/pathology* ; Treatment Outcome

ISR is the most widely used anal-preserving operation for ultra-low rectal cancer. It can be divided into total ISR, subtotal ISR and partial ISR according to the resection range of internal sphincter. The advantage of ISR is that it can preserve the sphincter while ensuring the safety of oncology for ultra-low rectal cancer, representing the state of the art. However, it still needs to face the problem that the quality of life will decline due to poor postoperative anal function. The conformal sphincter-preserving operation (CSPO) is a functional anal-preserving surgery improved on the basis of ISR. It is superior to ISR in the postoperative anal function and patients' quality of life. So it can be a new choice for ultra-low rectal cancer.
Humans ; Quality of Life ; Rectal Neoplasms/surgery* ; Anal Canal/surgery* ; Digestive System Surgical Procedures/methods* ; Anastomosis, Surgical ; Treatment Outcome

The anatomical studies of intersphincteric resection (ISR) have made remarkable progress in recent years. The anatomy of internal, external sphincter and hiatal ligament has been further understood. In this paper, the generation and functional mechanism of ISR related anatomy are described from the embryonic development process, and then the influence of hiatal ligament and internal sphincter on ISR surgery is analyzed respectively according to the anatomical characteristics. Finally, the correlation analysis of anatomical factors on the common problems of mucosal bleeding and instrument anastomosis in ISR is carried out. The objective of this paper is to improve the safety of ISR surgery by providing detailed anatomical explanations.
Humans ; Anal Canal/surgery* ; Rectal Neoplasms/surgery* ; Clinical Relevance ; Anastomosis, Surgical

Intersphincteric resection (ISR) surgery increases the rate of anal sphincter preservation in patients with ultra-low rectal cancers. However, the anastomotic site of ISR surgery is at risk for structural healing complications such as anastomotic leakage, anastomotic dehiscence, secondary anastomotic stenosis, chronic presacral sinus, rectovaginal fistula, and rectourethral fistula, which can lead to a persistent defunctioning ostomy or a secondary permanent colostomy. This article systematically describes the preoperative high-risk factors and characteristics of anastomotic site structural healing complications after ISR surgery, as well as the management of the anastomotic site during various stages including hospitalization, from discharge to one month after surgery, from one month after surgery to before stoma reversal, and after stoma reversal. This is to provide a clearer understanding of the risks associated with the anastomotic site at different stages of the healing process and to timely detect and actively manage related complications, thereby reducing the rate of permanent colostomy and truly achieving the dual goals of "survival benefit" and "quality of life improvement" in ISR surgery.
Female ; Humans ; Anal Canal/surgery* ; Quality of Life ; Anastomosis, Surgical/adverse effects* ; Anastomotic Leak/etiology* ; Rectal Neoplasms/complications* ; Retrospective Studies

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles. Results: (1) It was found that the rectourethralis muscle is closest to the deep transverse perineal muscle where the longitudinal muscle of the rectum extends into the posteroinferior area of the membranous urethra. The communicating branches of the neurovascular bundle (NVB) were identified at the posterior edge of the rectourethralis muscle on both sides. The rectum was found to be fixed to the membranous urethra through the rectourethral muscle, contributing to the anorectal angle of the anterior rectal wall. (2) Serial cross-sections from the anal to the oral side were examined. At the level of the external anal sphincter, the longitudinal muscle of the rectum was found to extend caudally and divide into two muscle bundles on the oral side of the external anal sphincter. One of these muscle bundles angled dorsally and caudally, forming the conjoined longitudinal muscle, which was found to insert into the intersphincteric space (between the internal and external anal sphincters). The other muscle bundle angled ventrally and caudally, filling the gap between the external anal sphincter and the bulbocavernosus muscle, forming the perineal body. At the level of the superficial transverse perineal muscle, this small muscle bundle headed laterally and intertwined with the longitudinal muscle in the region of the perineal body. At the level of the rectourethralis and deep transverse perineal muscle, the external urethral sphincter was found to occupy an almost completely circular space along the membranous part of the urethra. The dorsal part of the external urethral sphincter was found to be thin at the point of attachment of the rectourethralis muscle, the ventral part of the longitudinal muscle of the rectum. We identified a venous plexus from the NVB located close to the oral and ventral side of the deep transverse perineal muscle. Many vascular branches from the NVB were found to be penetrating the longitudinal muscle and the ventral part of rectourethralis muscle at the level of the apex of the prostate. The rectourethral muscle was wrapped ventrally around the membranous urethra and apex of the prostate. The boundary between the longitudinal muscle and prostate gradually became more distinct, being located at the anterior end of the transabdominal dissection plane. (3) Histological examination showed that the dorsal part of the external urethral sphincter (striated muscle) is thin adjacent to the striated muscle fibers from the deep transverse perineal muscle and the NVB dorsally and close by. The rectourethral muscle was found to fill the space created by the internal anal sphincter, deep transverse perineal muscle, and both levator ani muscles. Many tortuous vessels and tiny nerve fibers from the NVB were identified penetrating the muscle fibers of the deep transverse perineal and rectourethral muscles. The structure of the superficial transverse perineal muscle was typical of striated muscle. These findings were reconstructed three-dimensionally. Conclusions: In intersphincteric resection or abdominoperineal resection for very low rectal cancer, the anterior dissection plane behind Denonvilliers' fascia disappears at the level of the apex of the prostate. The prostate and both NVBs should be used as landmarks during transanal dissection of the non-surgical plane. The rectourethralis muscle should be divided near the rectum side unless tumor involvement is suspected. The superficial and deep transverse perineal muscles, as well as their supplied vessels and nerve fibers from the NVB. In addition, the cutting direction should be adjusted according to the anorectal angle to minimize urethral injury.
Humans ; Male ; Rectum/surgery* ; Anal Canal/anatomy & histology* ; Rectal Neoplasms/surgery* ; Proctectomy ; Urethra/surgery*