Thoracic Musculoskeletal Deformities Following Surgical Treatment of Esophageal Atresia - Thoracoscopic Versus Open Approach: A Retrospective Two Centers Cohort Study.

INTRODUCTION: Thoracic musculoskeletal deformities are significant complications following open correction of esophageal atresia (EA) during long-term follow-up. We aimed to compare the frequency and severity of thoracic musculoskeletal deformities after open and thoracoscopic repair of EA. We hypothesized that fewer deformities would occur following the less invasive thoracoscopic approach. METHODS: This retrospective study analyzed patients treated at two pediatric surgery departments in Poland between 2005 and 2021. The patient groups differed in surgical approach, operative techniques, indications for multi-staged surgery, and postoperative complications. The study encompassed all types of EA/TEF. The first group comprised 68 patients who underwent thoracoscopic esophageal atresia repair (Wroclaw), while the second group involved 44 patients who underwent open repair (Warsaw). Clinical data were retrospectively reviewed, with results considered significant at p < 0.05. RESULTS: The median age at examination was 6 years in the thoracoscopy group and 5.5 years in the thoracotomy group. In the thoracoscopy group, 53 out of 68 patients (77.9%) and in the thoracotomy group - 35 out of 44 patients (79.5%) were treated in one stage. The incidence of thoracic musculoskeletal deformities was significantly lower in the thoracoscopy group (1.5%) compared to the thoracotomy group (34.1%, p < 0.001). Scoliosis occurred significantly more often after thoracotomy (13.6% vs 1.5%, p = 0.016). There was no rib fusion (0% vs 37.1%, p < 0.001) and no scoliosis of =>20° (0% vs 6.8%, p = 0.058) after thoracoscopy. The coincidence of rib fusion and scoliosis was significant (9.1%, p = 0.022) for the open approach. In the thoracotomy group, multi-staged surgery and more frequent reoperations due to major complications were significantly associated with an increased occurrence of deformities. None of the patients after thoracoscopic multi-stage or complicated EA/TEF repair developed scoliosis. CONCLUSIONS: The frequency and severity of thoracic musculoskeletal deformities were significantly lower after the thoracoscopic approach. Thoracoscopy may be a more advantageous and preferred surgical approach for the EA/TEF treatment, although further randomized, controlled studies are necessary. Post-thoracotomy scoliosis may progress to a severity requiring surgery.

Interstitial Cells of Cajal and P2X3 Receptors at Ureteropelvic Junction Obstruction and Their Relationship with Pain Response.

Introduction: Etiopathogenesis and the symptomatology of ureteropelvic junction obstruction (UPJO) in the pediatric population has not yet been definitely clarified, suggesting a multifactorial nature of the condition. The aim was to analyze the association between the number of Interstitial Cells of Cajal (ICCs), as well as P2X3 receptors in ureteropelvic junction (UPJ) and the pain response in pediatric patients with hydronephrosis. Methods: 50 patients with congenital hydronephrosis underwent open or laparoscopic pyeloplasty at one of two departments of pediatric surgery and urology in Poland. Patients were divided into two groups according to the pain symptoms before surgery. A total of 50 samples of UPJ were obtained intraoperatively and underwent histopathological and immunohistochemical (IHC) analysis. Quantitative assessment of ICCs was based on the number of CD117(+) cells of adequate morphology in the subepithelial layer and the muscularis propria. Expression of P2X3 receptors was evaluated as the intensity of IHC staining. Results: Patients with hydronephrosis and accompanying pain were on average 60 months older (77 vs. 17 months) than children with asymptomatic hydronephrosis (p = 0.017). Symptomatic children revealed higher numbers of ICCs in both the subepithelial layer and in the lamina muscularis propria. In particular, symptomatic patients aged 2 years or more exhibited significantly higher numbers of ICCs in the subepithelial layer. Significant differences in the distribution of ICCs between the subepithelial layer and the lamina muscularis propria were observed in both groups. Expression of P2X3 receptors was limited to the urothelium and the muscle layer and correlated between these structures. There was no relationship between pain response and the expression of P2X3 receptors. Conclusions: ICCs and P2X3 receptors may participate in the pathogenesis of UPJO and in the modulation of pain response to a dilatation of the pyelocaliceal system. Explanation of the role of ICCs and P2X3 receptors in propagation of ureteral peristaltic wave and the modulation of pain stimuli requires further studies.

Thoracoscopic Stage Internal Traction Repair Reduces Time to Achieve Esophageal Continuity in Long Gap Esophageal Atresia.

OBJECTIVE: Management of long gap esophageal atresia (LGOA) is controversial. This study aims at comparing the management of LGOA between two high-volume centers. METHODS: We included patients with LGOA (type A and B) between 2008 and 2022. Demographics, surgical methods, and outcomes were collected and compared. RESULTS: The study population involved 28 patients in center A and 24 patients in center B. A surgical approach was thoracoscopic in center A, only for one patient was open for final procedure. In center B, 3 patients were treated only thoracoscopically, 2 converted to open, and 19 as open surgery. In center A primary esophageal anastomosis concerned 1 case, two-staged esophageal lengthening using external traction 1 patient, and 26 were treated with the multistaged internal traction technique. In 24 patients a full anastomosis was achieved: in 23 patients only the internal traction technique was used, while 1 patient required open Collis-Nissen procedure as final management. In center B primary anastomosis was performed in 7 patients, delayed esophageal anastomosis in 8 patients, esophageal lengthening using external traction in 1 case, and 9 infants required esophageal replacement with gastric tube. Analyzed postoperative complications included: early mortality, 2/28 due to accompanied malformations (center A) and 0/24 (center B); anastomotic leakage, 4/26 (center A) treated conservatively-all patients had a contrast study-and 0/24 (center B), 1 case of pleural effusion, but no routine contrast study; recurrent strictures, 13/26 (center A) and 7/15 (center B); and need for fundoplication, 5/26 (center A) and 2/15 (center B). Age at esophageal continuity was as a median of 31 days in center A and 110 days in center B. Median time between initial procedure and esophageal anastomosis was 11 days in center A and 92 days in center B. CONCLUSION: Thoracoscopic internal traction technique reduces time to achieve esophageal continuity and the need for esophageal substitution while maintaining a similar early complication rate.

Novel Left-Sided Thoracoscopic Approach to Recurrent Tracheoesophageal Fistula and Post-Fistula Tracheal Diverticula.

BACKGROUND: Recurrent tracheoesophageal fistula (RTEF) is usually a consequence of leakage or other complications after esophageal atresia repair performed through right-sided access. This results in extensive intrapleural adhesions, and open redo surgery poses a challenge. Alternatively, endoscopic endotracheal fistula obliteration usually requires repetitive procedures, and its success rate varies significantly between centers. We present a novel approach to recurrent fistulas. The innovation is in reaching the fistula through the virgin field via left-sided three-port thoracoscopy instead of classical right-sided thoracotomy. METHODS: This is a presentation of a new operative technique based on a retrospective case series of patients operated on at our department between 2016 and 2023. RESULTS: Eight patients after esophageal atresia repair (six with RTEF and two with post-fistula tracheal diverticula) were successfully treated with left-sided thoracoscopy. There were no conversions. One patient required rethoracoscopy for chylothorax. Another one, after RTEF closure, underwent multiple endoscopic obliterations of subsequent tracheal diverticulum. No other major complications nor re-recurrences were noted. CONCLUSIONS: Left-sided thoracoscopy in redo esophageal atresia has the advantage of a "virgin" operative field and grants feasible access to the RTEF or tracheal diverticulum. We believe that this approach is worth further exploration because it combines minimal invasiveness with high effectiveness without all the consequences of a thoracotomy.

Laparoscopic ureteroneocystostomy in the treatment of urinary incontinence due to ectopy of the ureters in female dogs: A pilot study.

Ureteral ectopia is rare and requires surgical treatment after a thorough diagnostic workup. Open surgical techniques for repositioning ectopic ureters have been known for many years and are well described in the literature. However, to the best of our knowledge, no laparoscopic method of correcting this pathology has been described, which, in our opinion, would benefit the animal in terms of the healing process and overall clinical outcomes. This study aimed to evaluate the possibility of laparoscopic treatment of ureteral ectopia, which causes urinary incontinence in dogs. All of the operated ten dogs presented in this study were client-owned females with symptoms of urinary incontinence due to a unilateral intramural ectopic ureter. A three-trocar laparoscopic technique was used to perform the ureteroneocystostomy of the ectopic ureter. In this article, clinicopathological data, imaging features, procedural findings, complications, and short- and long-term outcomes are presented. The procedure was feasible in all cases. No major postoperative complications were observed. Among the minor complications, slight hematuria was observed in three dogs, which resolved spontaneously. In the period of at least one year after surgery, no negative impact of the procedure was observed. Seven of the ten operated dogs regained urinary continence. The remaining three dogs required additional surgery (urethral bulking) because of a lack of improvement after adjuvant pharmacological treatment. Overall, good-to-excellent long-term outcomes can be achieved; however, dogs that remain incontinent after laparoscopic ureteroneocystostomy may require additional treatment.

Epigenetic Findings in Twins with Esophageal Atresia.

Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently observed in boys and in twins. The exact cause of isolated EA remains unknown; a multifactorial etiology, including epigenetic gene expression modifications, is considered. The study included six pairs of twins (three pairs of monozygotic twins and three pairs of dizygotic twins) in which one child was born with EA as an isolated defect, while the other twin was healthy. DNA samples were obtained from the blood and esophageal tissue of the child with EA as well as from the blood of the healthy twin. The reduced representation bisulfite sequencing (RRBS) technique was employed for a whole-genome methylation analysis. The analyses focused on comparing the CpG island methylation profiles between patients with EA and their healthy siblings. Hypermethylation in the promoters of 219 genes and hypomethylation in the promoters of 78 genes were observed. A pathway enrichment analysis revealed the statistically significant differences in methylation profile of 10 hypermethylated genes in the Rho GTPase pathway, previously undescribed in the field of EA (ARHGAP36, ARHGAP4, ARHGAP6, ARHGEF6, ARHGEF9, FGD1, GDI1, MCF2, OCRL, and STARD8).

Thoracoscopic approach for oesophageal atresia: A real game changer?

Almost 23 years have passed since the first thoracoscopic procedure was done. However, according to the recent study in USA, only 16% of newborns with oesophageal atresia and distal tracheooesophageal fistula are managed by thoracoscopic approach with a very high 53% conversion rate. The aim of presentation based on experience of one paediatric surgery centre is to prove that thoracoscopic approach for this malformation is a powerful tool with a potential to change the current results. It requires considerable experience that comes only from the high number of operated cases. The technique is one amongst the many others means which taken together may really help to improve the results. Thus, the question of centralisation for special rare congenital malformations comes back to mind. Is it rational to operate on only 2 or 3 cases a year in a single centre, or is it the time for centralisation and close co-operation, as has been done with biliary atresia treatment in the UK? LEVEL OF EVIDENCE: III.

Long-Gap Esophageal Atresia Repair Using Staged Thoracoscopic Internal Traction: The First Kazakhstan Experience.

Introduction: The treatment of long-gap esophageal atresia (LGEA) remains an important issue for pediatric surgeons. There are several methods of treating LGEA with various advantages and disadvantages. Thoracoscopic esophageal elongation using internal traction sutures has been developed more recently. Therefore, we wanted to report on our first experience in treating such pathology using staged thoracoscopic internal traction. Objective: To share our first experience in the treatment of LGEA using staged thoracoscopic internal traction. Methods: Three children with LGEA were treated at the University Medical Center "National Scientific Center for Maternal and Child Health" in the Pediatric Surgery Department, Nur-Sultan, Kazakhstan, using the method of staged thoracoscopic internal traction. Results: At the age of 3-4 months, 3 patients were operated on successfully using staged thoracoscopic internal traction. In any case, converting to an open thoracotomy was not needed and no anastomotic leakage was observed. In 2 cases, stenosis occurred that was treated by dilatation at least twice, 1 child had no stenosis. Conclusions: Thoracoscopic internal traction technique for LGEA was performed for the first time in Kazakhstan that showed its safety and possible future use in the surgical treatment of this congenital malformation.

Reliability and Validity of the Polish Version of the Esophageal-Atresia-Quality-of-Life Questionnaires to Assess Condition-Specific Quality of Life in Children and Adolescents Born with Esophageal Atresia.

Aim: This study reports the reliability and validity of the Polish version of the Esophageal Atresia Quality of Life (EA-QOL) questionnaires, which were originally developed in Sweden and Germany. Methods: A total of 50 families of children (23 aged 2 to 7, and 27 aged 8 to 17) with EA/TEF (esophageal atresia/tracheoesophageal fistula) participated in the study. The development and validation of the Polish version of the EA-QOL involved forward-backward translation of the survey items following the guidelines for cross-cultural translation, cognitive debriefing and evaluation of psychometric properties, including assessment of internal and retest reliability, linguistic validity, content validity, known-group validity and convergent validity. The medical records of patients and standardized questionnaires were used to obtain clinical data. The level of significance was p < 0.05. Results: The Polish versions of the EA-QOL questionnaires demonstrated strong linguistic and content validity, are slightly discriminative for esophageal and respiratory problems, but do not show convergent validity with the PedsQL 4.0 generic core scales. In terms of reliability, the internal consistency of the subscale and total scale of Polish versions as measured by Cronbach's alpha is good, and retest reliability is excellent. Conclusions: The Polish versions of the EA-QOL questionnaires meet most psychometric criteria that confirm the EA-QOL questionnaires' reliability and validity. This study enables application of these questionnaires in future research among children with EA in Poland and participation in international multicenter studies focusing on advancing knowledge of condition-specific QOL in this population. Future cross-cultural research using larger sample sizes is still needed to better address the relationship between condition-specific and generic QOL, as well as the discriminative ability of the EA-QOL questionnaires.

Laparoscopic and robot-assisted ureterocalicostomy for treatment of primary and recurrent pelvi-ureteric junction obstruction in children: a multicenter comparative study with laparoscopic and robot-assisted Anderson-Hynes pyeloplasty.

PURPOSE: This multi-institutional study aimed to assess the outcomes of laparoscopic ureterocalicostomy (LUC) and robot-assisted laparoscopic ureterocalicostomy (RALUC) and compare them with laparoscopic pyeloplasty (LP) and robot-assisted laparoscopic pyeloplasty (RALP) in children with pelvi-ureteric junction obstruction (PUJO). METHODS: The data of 130 patients (80 boys), with median age 7.6 years and median weight 33.8 kg, receiving minimally invasive treatment of PUJO over a 6-year period, were retrospectively analyzed. Patients were grouped according to the operative approach: G1 included 15 patients, receiving LUC (n = 9) and RALUC (n = 6), and G2 included 115 patients, receiving LP (n = 30) and RALP (n = 85). Patient characteristics and operative outcomes were compared in both groups. RESULTS: The median patient age and weight were significantly higher in G1 than in G2 [p = 0.001]. The median operative time was similar in both groups (157.6 vs 150.1 min) [p = 0.66] whereas the median anastomotic time was shorter in G1 than in G2 (59.5 vs 83.1 min) [p = 0.03]. The surgical success rate was similar in both groups (100% vs 97.4%) [p = 0.33]. Post-operative complications rate was higher in G1 than in G2 (20% vs 6.1%) but all G1 complications were Clavien 2 and did not require re-intervention. CONCLUSION: LUC/RALUC can be considered safe and effective alternative approaches to LP/RALP for PUJO repair and reported excellent outcomes as primary and salvage procedures. Robot-assisted technique was the preferred option to treat most patients with recurrent PUJO in both groups.

Preserved Voluntary Micturition Control despite Early Urinary Diversion in Infancy-A Clue to a New Strategy.

Micturition is an involuntary process based on spinal arcs in infants and children until a defined age. The awareness and voluntary control of voiding depends on specific areas in the central nervous system, especially cortical regions. The cells and connections between these areas develop over time and regulate the voiding process. The ability to maintain continence and to adjust physiological needs to appropriate environmental conditions is considered to be acquired through systematic behavioral education, especially toilet training. The recommendations specify the age at which to start establishing the relevant habits. The purpose of these guidelines is to achieve proper micturition control development and to avoid functional lower urinary tract (LUT) disorders. We present a case of a patient who underwent complete urinary diversion in infancy and reconstruction of the urinary tract eleven years later. For eleven years, she had an empty bladder and no toilet training. After undiversion, she regained full continence in a short space of time. The presence of proper LUT function and a controlled micturition process raises the question of the standard toilet training recommendations' validity. The aim of our work focuses on the following question: Is toilet training the only way to achieve micturition skills and proper urinary tract function? The history of our patient and the literature reveal that voluntary micturition may develop without stimulating signals of filling from bladder receptors and independently of recommended behavioral education, so toilet training seems to not be necessary.

Biomechanics of esophageal elongation with traction sutures on experimental animal model.

Esophageal elongation is one of the methods of long gap esophageal atresia treatment. The aim of the study was to determine the best type of traction suture for esophageal lengthening on an animal model. White Pekin Duck's esophagi were used as a model (fresh-frozen and thawed). The esophagus was cut in half, then both ends were sutured together and extended on a tensiometer. Tested sutures involved simple suture, suture aided by a single or double clip, and suture aided by pledget (10 samples each). Constant and 2 methods of intermittent traction were also compared. The histological study showed similarities between duck's and newborn's esophagus. The highest maximal force was achieved with pledget suture (F = 8.59 N ± 1.45 N), then with double clip (F = 5.74 N ± 1.29 N) and the lowest with single suture (F = 3.80 N ± 0.54 N) (p < 0.001). Pledget suture also allowed for the greatest elongation (p < 0.01). Intermittent traction results in better elongation at the same breaking strength as constant traction (p < 0.05) if traction is maintained during breaks. Reinforced sutures (pledget or double clip) should be taken into consideration in internal traction. When performing traction sutures, it is worth step by step carefully tightening the sliding knot in short periods before its final binding.

What Should Be the Topics of a Prospective Study on Ovarian Masses in Children?-Results of a Multicenter Retrospective Study and a Scoping Literature Review.

PURPOSE: to determine management problems of ovarian masses in girls in order to form a baseline for prospective randomized studies of the established topics and quality improvement of our management. MATERIALS AND METHODS: We performed a national analysis of clinical aspects of ovarian masses in girls operated on in Poland, analyzed retrospectively medical files of all consecutive patients aged 0-18 who underwent surgeries for ovarian lesions between 2012 and 2017 at 17 pediatric surgical departments and complemented the analysis with a scoping review of a recent primary research related to ovarian masses in children. RESULTS: The study group comprised 595 patients. Forty-four (7.39%) girls were diagnosed with malignant tumors. The overall preservation rate was 64.54%. The analysis revealed that positive tumor markers (OR = 10.3), lesions larger than 6 cm (OR = 4.17) and solid mass on ultrasound examination (OR = 5.34) are interdependent variables differentiating malignant tumors from non-malignant lesions (X42 = 79.1; p = 0.00000). Our scoping review revealed 10 major branches of research within the topic of ovarian masses in pediatric population. CONCLUSIONS: We have developed an overview of the field with the emphasis on the local environment. Our next step is a multi-institutional prospective study of a quality improvement project implementation based on the obtained knowledge.

Ingrowing Liver as Atypical Recurrent Diaphragmatic Hernia Presentation-Diagnostic and Treatment Difficulties: A Case Report.

(1) Introduction: Recurrent diaphragmatic hernia is a relevant diagnostic and treatment dilemma. We have presented a patient with ingrowing liver as an atypical diaphragmatic hernia recurrence and discussed major aspects of diagnostic methods and the selection of an appropriate operative treatment. (2) Case description: We discuss a case of a patient with right-sided recurrent CDH (Congenital Diaphragmatic Hernia) who had primary thoracoscopic repair in newborn period. During infancy and early childhood, the patient presented recurrent upper and lower respiratory tract infections and bronchial hyperreactivity. The clinical picture was initially unclear. A CT scan was inconclusive to diagnose a recurrence. The patient was scheduled to have a re-thoracoscopy. A part of the liver was herniated into the pleural cavity. This fragment of 'ingrowing' liver was removed, and the diaphragmatic secondary defect was repaired. (3) Conclusions: This case proved that thoracoscopy can be a preferred technique in the diagnosis and treatment of CDH recurrence.

First genome-wide association study of esophageal atresia identifies three genetic risk loci at CTNNA3, FOXF1/FOXC2/FOXL1, and HNF1B.

Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) is the most common congenital malformation of the upper digestive tract. This study represents the first genome-wide association study (GWAS) to identify risk loci for EA/TEF. We used a European case-control sample comprising 764 EA/TEF patients and 5,778 controls and observed genome-wide significant associations at three loci. On chromosome 10q21 within the gene CTNNA3 (p = 2.11 × 10-8; odds ratio [OR] = 3.94; 95% confidence interval [CI], 3.10-5.00), on chromosome 16q24 next to the FOX gene cluster (p = 2.25 × 10-10; OR = 1.47; 95% CI, 1.38-1.55) and on chromosome 17q12 next to the gene HNF1B (p = 3.35 × 10-16; OR = 1.75; 95% CI, 1.64-1.87). We next carried out an esophageal/tracheal transcriptome profiling in rat embryos at four selected embryonic time points. Based on these data and on already published data, the implicated genes at all three GWAS loci are promising candidates for EA/TEF development. We also analyzed the genetic EA/TEF architecture beyond the single marker level, which revealed an estimated single-nucleotide polymorphism (SNP)-based heritability of around 37% ± 14% standard deviation. In addition, we examined the polygenicity of EA/TEF and found that EA/TEF is less polygenic than other complex genetic diseases. In conclusion, the results of our study contribute to a better understanding on the underlying genetic architecture of ET/TEF with the identification of three risk loci and candidate genes.

Recommendations of procedures to follow in the case of ovarian lesions in girls.

This study presents current recommendations of the Polish Association of Pediatric Surgeons (PTChD) regarding diagnostics and treatment of ovarian lesions in girls. They are based on many years of the authors' clinical experience as well as a review of international literature and include practical clinical guidelines. The recommendations were formulated in cooperation with the Polish Association of Pediatric Oncology and Hematology (PTOHD), Polish Pediatric and Adolescent Gynecology Section of the Polish Society of Gynecologists and Obstetricians (PTG) and Polish Pediatric Section of the Polish Society of Radiology (PLTR). Only better understanding of prepubertal ovarian biology and natural history of its pathology may help to introduce efficient and safe diagnostic and therapeutic strategies for girls. The prepared document has been supplemented with treatment algorithms.

Occurrence of Esophageal Atresia With Tracheoesophageal Fistula in Siblings From Three-Generation Family Affected by Variable Expressivity MYCN Mutation: A Case Report.

The MYCN oncogene encodes a transcription factor belonging to the MYC family. It is primarily expressed in normal developing embryos and is thought to be critical in brain and other neural development. Loss-of-function variants resulting in haploinsufficiency of MYCN, which encodes a protein with a basic helix-loop-helix domain causes Feingold syndrome (OMIM 164280, ORPHA 391641). We present an occurrence of esophageal atresia (EA) with tracheoesophageal fistula in siblings from a three-generation family affected by variable expressivity of MYCN mutation p.(Ser90GlnfsTer176) as a diagnostic effect of searching the cause of familial esophageal atresia using NGS-based whole-exome sequencing (WES). All of our affected patients showed microcephaly and toe syndactyly, which were frequently reported in the literature. Just one patient exhibited clinodactyly. None of the patients exhibited brachymesophalangy or hypoplastic thumbs. The latest report noted that patients with EA and Feingold syndrome were also those with the more complex and severe phenotype. However, following a thorough review of the present literature, the same association was not found, which is also confirmed by the case we described. The variable phenotypic expression of the patients we described and the data from the literature guide a careful differential diagnosis of Feingold syndrome even in cases of poorly expressed and non-specific symptoms.

Laparoscopic-assisted percutaneous herniorrhaphy as an alternative to open surgery technique in farm swines.

BACKGROUND: Despite numerous experimental studies presenting laparoscopic treatment of inguinal hernia in a pig model so far no described technique has been used in clinical patients of this species. Minimal invasiveness and the simplicity of closure of the inguinal canal using the Percutaneous Internal Ring Suturing (PIRS) technique makes it the world's first technique for laparoscopic treatment of inguinal hernia in pigs as clinical patients. AIM: This study aims to assess the applicability and effectiveness of the laparoscopic PIRS technique in the treatment of inguinal hernia in pigs as clinical patients and to compare the PIRS technique with the open surgery technique, which is currently being used. METHODS: The study was conducted on 22 non-castrated male pigs with inguinal hernia (clinical patients), divided into two equal groups: PIRS and open surgery (OS). In the PIRS group, the inner inguinal ring was closed with an optical trocar inserted at the umbilicus level and an injection needle with a suture material inserted percutaneously over the inguinal canal. The suture material was threaded through the inner inguinal ring and then tied, leaving the knot under the skin. As a result to this the inguinal canal was closed. In the OS group the procedure was performed with open access above the inguinal canal where, after dissection of the vaginal processus and reducing the contents of the hernia to the abdominal cavity, it was ligated as close to the inguinal canal as possible, and the wound was then closed in layers. RESULTS: All operated pigs returned to full fitness immediately after recovery from anesthesia. There was one case of hernia recurrence in the PIRS group. In the OS group all the operated pigs had a temporary swelling of the postoperative wound and the scrotum on the side of the operated inguinal hernia, which was not found in the PIRS group. CONCLUSIONS: The effectiveness of the PIRS technique is comparable to that of open surgery. Considering the simplicity of the PIRS procedure and its minimal invasiveness, this technique may be used as an alternative to the open technique in the treatment of inguinal hernias in pigs not subjected to surgical castration.