PURPOSE:Retained esophageal button batteries (BBs) cause significant morbidity in children. Current guidelines recommend oral honey administration in children over 1 year and esophageal irrigation with 0.25 % acetic acid (ACA) after BB removal, but supporting evidence is limited. We aimed to develop a dynamic in vitro esophageal model to evaluate these interventions. METHODS:Our novel model consisted of fresh porcine oesophagi suspended in an environment simulating body temperature, peristalsis, and saline perfusion. BBs or sham BBs were placed in the oesophagus. Honey was administered at specific intervals after BB insertion. After BB removal, the lesions were washed with ACA or buffer solution. Paraffin slides were stained with hematoxylin and eosin (HE) to quantify the ulceration. RESULTS:The mean pH was significantly lower in samples exposed to honey (p≤0.0001) and the voltage discharge was reduced with honey as well (p≤0.0001). Application of honey resulted in macroscopically smaller ulcers than in untreated oesophagi. HE staining confirmed the macroscopic results with significantly reduced ulcers with honey application (p < 0.009). Irrigation with ACA had no effect. CONCLUSION:We developed a dynamic in vitro model of oesophageal button battery ingestion by including peristalsis, body temperature, an upright lumen and saline perfusion. Our data supports the recommendations that oral honey application before endoscopic battery removal protects the mucosa after oesophageal BB retention, whereas ACA irrigation at the time of BB removal showed no effect in this study.

PURPOSE:Pediatric inguinal hernia repair (PIHR) is a common procedure performed using either open or laparoscopic techniques. Both approaches require detailed anatomical knowledge and specialized training. To address these training needs, we developed a low-cost, 3D-printed Pediatric Open and Laparoscopic Integrated Simulator for Inguinal Hernia Repair (POLISHeR). This study aimed to validate POLISHeR as a simulation tool for essential PIHR skills. METHODS:Experienced pediatric surgeons and surgical trainees performed simulated PIHR using POLISHeR. Participants evaluated the simulator's face and content validity using a 5-point Likert scale. Two experienced pediatric surgeons assessed video-recorded simulations using procedure (PCL) and error (ECL) checklists. An Entrustable Professional Activity (EPA) scale measured participants' competence. Construct validity was assessed by comparing expert and trainee performance using the Mann-Whitney U test. RESULTS:Twenty-six participants completed simulations (open: n = 11; laparoscopic: n = 15), including 14 expert pediatric surgeons (open: n = 5; laparoscopic: n = 9). In laparoscopic PIHR, trainees made significantly more errors (p < 0.001), completed fewer key steps (p < 0.001), and received lower EPA scores (p < 0.001) than experts. In open PIHR, trainees made more errors (p = 0.03), had lower EPA scores (p = 0.05), and received lower PCL scores (p = 0.410), though not statistically significant. Experts reported strong anatomical realism and accurate step representation. CONCLUSION:POLISHeR demonstrates strong face, content, and construct validity. It effectively differentiates between expert and trainee performance and represents an affordable, practical tool for teaching and evaluating PIHR skills.

Background: Inguinal hernia is a common childhood pathology, making inguinal hernia repair (IHR) a key pediatric surgical procedure. Surgical success relies heavily on knowledge of groin anatomy, and both open and laparoscopic approaches require considerable repetition to master. As surgical simulators have been shown to improve performance for other surgical procedures, we developed a combined open and laparoscopic pediatric IHR simulator-named POLISHeR-to train residents, fellows, and practicing surgeons in both types of repair. Methods: A CT scan of a 7-year-old was scaled down to create a virtual 3D model of a 2-year-old using our validated protocol for anatomical modelling. Physical replicas of the pelvis, abdominal wall, aorta, and inferior vena cava were 3D-printed to create a life-size unisex base for open and laparoscopic IHR, while a small mobile unisex base was 3D-printed for open IHR. We recruited six experienced surgeons and trainees to pilot the face validity of POLISHeR. Results: After multiple iterations, we successfully developed a modular 3D-printed simulator for open and laparoscopic IHR. Printing the life-size base cost $331.69 USD, whereas the small base cost $17.54. An open modular cartridge cost $9.92 for females and $14.21 for males, whereas replacement parts cost under $1.30. A laparoscopic modular cartridge cost $6.16 for females and $10.91 for males, whereas replacement parts cost $0.28. Pilot study participants provided encouraging feedback with respect to POLISHER's face validity. Conclusions: Our low-cost simulator holds promise for enhancing training for pediatric IHR. Our next step is to conduct validation trials for trainees and practicing surgeons in both well-resourced and resource-limited settings. Level of Evidence: Not applicable. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Background:Simulator training is an efficient training tool to develop surgical novice's basic laparoscopic skills.Currently simulator training takes mainly place in simulation centers at hospitals and universities.Additionally, most trainees have to use overtime for training purposes since it is mostly not included during normal working hours.Recent studies also indicated the possibility of low cost at-home training for laparoscopic surgery, opening up new personalized training possibilities.Such modalities support surgeons' initial acquisitions of basic laparoscopic skills as well as continuous development.Furthermore training at home could facilitate the possibility of skill retention, which might be important for longer times without specialized surgical training.This could for example include research time, maternity leave or gaining further education.Nevertheless, most currently available simulators are expensive and require additional equipment (e.g.monitors, stands, PCs) and, therefore, are not feasible for at-home training.Recently developed low-cost simulators show great promise to bridge this gap.We aimed to investigate if low-cost simulators are comparable to more expensive box trainers regarding surgeons performance and likability. Materials and methods:This randomized, open-label crossover multi-center study was performed at Dresden and Mannheim's university hospitals.Participants were randomly assigned either to the "Laparoscopy Boxx-Pro" (LBX) or "Lübecker Toolbox" (LBT) simulator and switched afterwards.The "Laparoscopy Boxx-Pro" is developed by the Dutch "Laparoscopy Boxx" company.The simulator consists of wooden parts, can be stored and shipped easily and is simple to build up.The simulator costs 309€ including instruments and does not have a built in camera device but allows for the use of a phone or tablet with a build-in camera.The "Lübecker Toolbox'' on the other hand is a laparoscopic box trainer produced by the German company "Lübecker Toolbox''.This simulator costs about 4,200€ without instruments and a screen.Each participant performed four laparoscopic tasks (Peg transfer, circle cutting, laparoscopic suture and knot, Balloon resection) on both the LBX and LBT.During the tasks, force exertion and completion time were measured using the ForceTrap system (Medishield B.V., Delft, The Netherlands).Additionally, errors were recorded, and the psychological workload was assessed using the NASA-TLX score.Furthermore, participants were tasked to rate the simulator regarding usability, view, and ease of performing the tasks in a self-designed questionnaire using a five-point Likert Skala, with one being the best and five the worst. Results:In total, seven abdominal surgeons, seven urologists, and sixteen medical students participated in the evaluation of the simulators.Of the 30 participants, the majority (80%) rated their laparoscopic skill level as beginners, whereas six participants (20%) rated their skills as proficient.The PEG task was performed significantly slower using the LBX compared to the LBT (192,1s vs 175,3 s; p=0.049).In contrast, the amount of time for the balloon resection were significantly faster performed with the LBX (compared to the LBT (198,6s vs 223,1s; p=0.049;).Similar, for the surgical knot and suturing taks a s18

Background: Esophageal strictures following esophageal atresia repair are a source of significant morbidity. To test new therapeutic approaches, we designed a piglet model of esophageal stricture by resecting variable lengths of esophagus with subsequent re-anastomosis. This study describes the model and validates its physiologic impact by blinded analysis of the weight gains of the piglets. Methods: A total of 24 two-week old Pietrain piglets had esophageal resections performed, ranging from 0 to 5 cm, with the goal of inducing postoperative esophageal strictures. Postoperative body-weights were evaluated by repeated analysis of variance followed by pairwise group-comparisons based on estimated marginal means. In addition, body weight was modeled by linear-mixed model regression. Different resection lengths were compared. The esophagi were evaluated postmortem for stricture. Results Of 24 operated piglets, 23 reached the endpoint, and 90% developed an esophageal stricture that was radiologically visible in a contrast study, as well as appreciable macroscopically in the necropsy. We found differences in pre- and postoperative body weights for all piglets (F (1, 18) = 298.54, p < 0.001), but no differences between resection lengths (F (4, 18) = 0.36, p = 0.837). Conclusion Our model of postoperative esophageal stricture offers the opportunity to investigate potential treatments for strictures associated with esophageal atresia, since it reliably induces strictures and results in minimal loss of animals. The similar body weight gain in all groups indicates that stricture is mainly the result of esophageal resection and re-anastomosis, regardless of the length of the resected segment.

Anastomotic tension has a highly negative effect on intestinal anastomoses as well as shortand long-term results in paediatric oesophageal surgery, whose primary aim is to preserve the native oesophagus as it is the best conduit. Anastomotic tension has however been measured mainly subjectively due to the lack of a method to objectively document the applied traction forces. The literature documents only one example in which anastomotic tension in paediatric oesophageal surgery has been measured objectively: In 8-week-old piglets, oesophageal segments between 0 and 6.5 cm had been resected and anastomotic tension during approximation of the oesophageal ends was measured using 2 dynamometers. In these measurements, the dynamometers were attached to a single 4-0 silk stitch on each side of the oesophageal ends and the readout of the dynamometers was recorded when both instruments documented the same measurement of force. As the single stitches were removed afterwards and replaced by sutures for an anastomosis, this can only be interpreted as an approximation of the anastomotic tension. A problem similar to anastomotic tension in paediatric oesophageal surgery exists in microvascular anastomoses, because increasing anastomotic tension has a substantial negative effect on the reconstructive outcome. Consequently, a tensiometer had been developed and tested in femoral arteries of sacrificed rats, which measured anastomotic tension by a spring balance, but had to be held directly above the expected anastomotic line in an angle of 90°. None of these 2 methods had been fit for translational clinical use. We therefore designed an instrument that could have been suitable for translation by using a typical knot-pusher (Model 26167 KNS, Karl Storz, Tuttlingen, Germany) to which a selfdesigned system was adapted that measured the force applied to the knot-pusher, while pushing the stitches together, by the linear deflexion of the elastically mounted measurement module (Figure 1). The resulting forces were measured by a tensiometer attached to the instrument. Using the knot-pusher had the substantial advantage of being useful for both the open and thoracoscopic approach. It was vigorously tested in in-vitro experiments in oesophagi mounted in a test-stand, in which the resulting anastomotic tension was within ranges that were expected by preceding research in piglet oesophagi. Despite these promising in-vitro results, testing during an experiment including oesophageal resection in live piglets revealed that our instrument was not suitable for in-vivo use either: anastomotic tension was almost identical between the different resection lengths between 0 and 5 cm according to our instrument, whereas the operating surgeon’s five-fingered archaic tensiometer measured substantial differences in anastomotic tension. Reasons for the discrepancy may have been frictional resistance resulting from the deflection of the suture within the knot-pusher, non-standardised angles of the knotpusher in relation of the main tension vector orientation or problems with interface between suture and tensiometer. Consequently, we could only prove that our concept was not yet ‘ready for take-off’ for measuring anastomotic tension in paediatric oesophageal surgery. However, as we had invested a substantial

Background: Training platforms such as the Fundamentals of Laparoscopic Surgery have become an integral part of postgraduate adult general surgical education. So far, however, there is no such universal tool for pediatric minimal-invasive surgery (MIS). We therefore designed and validated a novel 3D printable pediatric MIS simulation program.Methods: The SuSiPed (Surgical Simulation in Pediatrics) curriculum consists of 6 MIS training modules: camera guidance, shell transfer, figure cutting, cyst resection, single interrupted suturing, and slipknot suturing. All modules can be 3D printed, and thus manufactured in a low-cost, sustainable and repro-ducible fashion. Instructional videos for the participants for each module were created. For validation, a group of medical students and surgical residents were compared to a group of pediatric surgical spe-cialists with experience in MIS. All participants performed the entire SuSiPed curriculum 3 times, measuring time to task completion and technical mistakes. The results of the last attempt were compared using Welch's T-test.Results: There were 25 participants in the novice group and 5 in expert group. Times to task completion were lower in the expert group for all modules except camera guidance. Errors were significantly more frequent during slipknot suturing in the novice group, while there were no difference in the other modules. Conclusion: Our novel training platform showed good construct validity for 5 out of 6 modules, while scores of camera navigation was not associated with prior experience. The SuSiPed platform is useful for pediatric minimal-invasive surgery training and evaluation, even in low-resource countries where expensive simulators are not affordable. Level of evidence: Level III, Validation Study.(c) 2022 Elsevier Inc. All rights reserved.

Thoracoscopic esophageal atresia (EA) repair affords many benefits to the patient; however, intracorporeal suturing of the anastomosis is technically challenging. Esophageal magnetic compression anastomosis (EMCA) is a compelling option for endoluminal EA repair, but available EMCA devices have prohibitive rates of recalcitrant stricture. Connect-EA is a new endoluminal EMCA device system that employs 2 magnetic anchors with a unique mating geometry designed to reliably create a robust anastomosis and decrease rates of leak and stricture. We describe our first-in-human experience with this novel endoluminal device for staged EA repair in 3 patients (Gross type A, B, and C) at high risk for conventional surgical repair. First, the esophageal pouches were approximated thoracoscopically. After acute tension subsided, the device anchors were endoscopically placed in the esophageal pouches and mated. Anchors were spontaneously excreted in 2 cases. Endoscopic repositioning and retrieval of the anchors were required in 1 patient because of narrowed esophageal anatomy. There were no perioperative complications. Patients were managed for 14 to 18 months. The strictures that developed in the patients were membranous and responded well to dilation alone, resolving after 4 to 5 outpatient dilations. Gastrostomies were closed between 6 and 11 months and all patients are tolerating full oral nutrition. Early experience with this new endoluminal EMCA device system is highly favorable. The device offers considerable benefit over conventional handsewn esophageal anastomosis and anastomotic outcomes are superior to available EMCA devices.

Background/PurposePrevious studies have shown that a patent, watertight esophageal anastomosis can be accomplished safely using specially-shaped magnets in piglets. However, it is unclear whether such a magnetic esophageal compression anastomosis (MECA) remains patent in the long-term. The purpose of this study was to evaluate the long-term outcome of MECA in an experimental pig model over an observation period of 2 months.MethodsTen piglets underwent creation of an MECA with custom-made 8 mm magnets and a U-shaped esophageal bypass loop to allow peroral nutrition at eight weeks of life. Two weeks later, the bypass loop was closed surgically, requiring the pigs to swallow via the newly created magnetic compression anastomosis. The pigs were fed soft chow for 2 months. They were monitored for weight gain and signs of dysphagia. At the endpoint of two months, esophagoscopy and contrast esophagography was performed. After removal of the esophagus, the tissues were macroscopiocally and histologically assessed.ResultsSix piglets survived until the endpoint. In two pigs, closure of the bypass loop failed, these demonstrated mean weight gain of 792 gs/day [95% Confidence interval 575 to 1009 gs/day]. Weight gain in four pigs that exclusively fed via the magnetic anastomosis averaged 577 gs/day [95% confidence interval 434 to 719 gs/day (p = 0.18)]. There were no signs of dysphagia. All magnets passed with the stool within 16 days. After 2 months, a well-formed magnetic compression anastomosis was visible and easily negotiated with a 6.5 mm endoscope. Esophogram and macroscopic findings confirmed patentency of the esophageal anastomoses. Histopathology showed a circular anastomosis lined with contiguous epithelium.ConclusionMECA creates a long-term functional and patent anastomosis in pigs. This concept may facilitate minimally-invasive esophageal atresia repair by obviating a technically challenging and time-consuming hand-sewn anastomosis.

Levrat's rat model is often the first choice for basic studies of oesophageal adenocarcinoma. The position of the tracheal bifurcation represents the preferred location for the high-intrathoracic anastomosis following oesophagectomy for cancer and is thus of importance in basic research of oesophageal adenocarcinoma. In addition, it is also the typical location for trachea-oesophageal fistulae in congenital oesophageal atresia and its rat model. We thus analysed whether the position of the tracheal bifurcation would be affected by a rat's growth throughout life. We analysed absolute and relative carinal position of the tracheal bifurcation and its relationship to oesophageal length in two cohorts of Sprague Dawley rats (RjHan:SD) of both sexes: one consisted of 30 eight-week old rats and the other of 20 rats aged between 15 and 444 days. We analysed their relationship by Pearson's r and univariate linear regression. Bootstrap confidence intervals were calculated for all calculated coefficients. Absolute carinal position correlated with oesophageal length in the eight-week old cohort (r=0.4, 95% CI: 0.08-0.71, p=0.015) and those of different ages (r=0.92, 95% CI: 0.77-0.96, p=0.0066). Absolute carinal position increased with oesophageal length in both cohorts (F(1,28)=5.56; p=0.0256 and F(1,18)=94.93; p<0.0001 respectively). Consequently, relative tracheal bifurcation position was not influenced by oesophageal length in both cohorts (F(1,28)=2.49; p=0.1257 and F(1,18)=1.92; p=0.183). Absolute carinal position increased with oesophageal length, but relative position remained constant at around 30% of proximal oesophageal length throughout life.

Swine models had been popular in paediatric oesophageal surgery in the past. Although being largely replaced by rodent models, swine experienced a revival with the establishment of minipig models. However, none of them has ever been investigated for similarity to humans. We conducted a pilot study to determine whether three-week old Pietrain piglets and three-month old Aachen Minipigs are suitable for experimental paediatric oesophageal atresia surgery. We tested the operation's feasibility, performed a necropsy, weighed organs, measured organ length and calculated relative weights and lengths, and measured laboratory parameters. We used multidimensional scaling to assess the similarity of the swine breeds with previously published human data. Pietrain piglets had a higher a priori bodyweight than Aachen Minipigs (Δ = 1.31 kg, 95% confidence interval (CI): 0.37–2.23, p = 0.015), while snout-to-tail length was similar. Pietrain piglets had higher absolute and relative oesophageal lengths (Δ = 5.43 cm, 95% CI: 2.2–8.6; p = 0.0062, [Formula: see text] = 0.0083 and Δ = 11.4%, 95% CI: 5.1–17.6; p = 0.0025, [Formula: see text] = 0.0053). Likewise, absolute and relative small intestinal lengths were higher in Pietrains, but all other parameters did not differ, with the exception of minor differences in laboratory parameters. Multidimensional scaling revealed three-week old Pietrain piglets to be similar to two-month old humans based on their thoracoabdominal organ weights. This result indicates three-week old Pietrain piglets are a suitable model of paediatric oesophageal atresia surgery, because clinically many procedures are performed at around eight weeks age. Three-month old Aachen Minipigs were more dissimilar to eight-week old humans than three-week old Pietrain piglets.

Introduction Long-gap esophageal atresia represents a distinct entity among the esophageal atresia spectrum. In many patients, achieving a reasonable anastomosis depends on some millimeters of tissue. We aimed to determine what effect the suturing technique would have on esophageal ex vivo elongation as it may determine the strength of a primary anastomosis. Materials and Methods In an analysis of porcine esophagi from animals for slaughter (100-120 days old with a weight of 100-120kg), we determined esophageal length gain of simple continuous and simple interrupted suture anastomoses subjected to linear traction until linear breaking strength was reached. Statistical power of 80% was ensured based on an a priori power analysis using five specimens per group in a separate exploratory experiment. Results The simple continuous suture anastomosis in 15 porcine esophagi ( =4.47cm, 95% confidence interval: 4.08-4.74cm) outperformed the simple interrupted suture anastomosis in another 15 esophagi ( =3.03cm, 95% confidence interval: 2.59-3.43cm) in length gain (Delta = 1.44cm, 95% confidence interval: 0.87-2.01cm, p <0.0001). Conclusion Simple continuous anastomoses achieved higher length gain compared with simple interrupted suture anastomoses. This effect warrants an experimental assessment in vivo to assess its potential merits for clinical applicability.

Background: 8-week old Sprague Dawley rats represent the standard rodent model of oesophageal surgery, which is challenging and might be eased by larger oesophageal lengths. Therefore, we aimed to analyse whether oesophageal length would linearly increase with bodyweight and ensure comparable experimental conditions. Methods: We analysed 41 8-week old Sprague Dawley rats of both sexes by linear regression of oesophageal length with sex as an interaction term for bodyweight. Based on exploratory investigations, analyses were powered to 80% for a deviation of the regression's slope from zero. Results: Linear regression was statistically significant with F(3,37)=3.29, P=0.0312 with an adjusted R-2 of 0.15 (95% CI: 0.02-0.43). Oesophageal length could be modelled by 4.56 (95% CI: 1.45-6.69)+0.007 (95% CI: -0.002-0.019) x bodyweight in grams+6.7 (95% CI: 1.86-11.1) x sex (1=male) - 0.02 (95% CI: -0.04-(-0.005)) x bodyweight x sex. Exploration of the interaction revealed that oesophageal length increased with bodyweight for female rats, but decreased in males. Conclusions: Sex represents a major interaction for oesophageal length in an age-adjusted cohort of Sprague Dawley rats. This may have relevant implications for reproducibility of rat models of oesophageal surgery, but may be different in inbred strains.

Introduction: Fashioning a patent, watertight anastomosis in patients with esophageal atresia is a challenging task in pediatric surgery, particularly when performed under tension. A reproducible suture-less alternative would decrease operative time. We evaluated magnetic esophageal compression anastomoses in a novel bypass-loop swine model. Methods: Eight-week-old piglets underwent thoracotomy to mobilize the esophagus at the carina to create a U-shaped loop. Custom-made 8 mm diameter Neodymium Magnets were inserted into the esophagus proximal and distal to the loop, then mated side-to-side at the future anastomosis site. Pigs were observed for 8 (n = 4), 10 (n = 6), and 12 (n = 2) days and then sacrificed. The magnetic compression anastomosis was evaluated macroscopically, by radiography, burst pressure testing, and histology. Results: All 12 pigs survived until the endpoint. Separation of the magnets occurred at a median of 9 days. Contrast esophagrams showed plenty and no leak. All anastomoses withstood pressures well over 13 kPa without leak. Histopathology showed epithelialized circular scar tissue. Conclusion: Magnetic compression anastomoses of the esophagus using our specially-designed magnets are formed between the 8th and 10th postoperative day, are patent and mechanically resistant to supraphysiologic intraluminal pressures. These data lay the basis for a potential clinical application in patients born with esophageal atresia. (C) 2019 Elsevier Inc. All rights reserved.

Introduction: Swine had special roles in the development of minimally invasive procedures to treat vesicoureteral reflux, and minipigs have been gaining ground in recent years in experimental pediatric urology as they combine small size with less vulnerable adult physiology, but their suitability as a model has never been assessed. We therefore compared a landrace piglet with a juvenile minipig to elucidate comparability. Methods: We evaluated five 3-week old Pietrain piglets and five 3-month old Aachen Minipigs as representatives of landrace and minipig models based on their expected bodyweight being similar to a newborn human. We compared renal weight, volume – via the ellipsoid formula – and ureteral length. In addition, we calculated porcine renal function via Gasthuys’ formula. In order to compare the groups with previously published values for infants, we used resampling techniques to allow comparison to humans. Results: Renal weight was higher in humans than in Pietrain piglets (ΔL = 7.6 g; ΔR = 5.4 g) and Aachen Minipigs (ΔL = 11 g; ΔR = 9.4 g). Renal volumes in humans were higher than in both Pietrain piglets (ΔL = 5.6 mL, p < 0.001; ΔR = 3.7 mL, p = 0.004) and Aachen Minipigs (ΔL = 8.1 mL; ΔR = 6.6 mL; both p < 0.001). Ureteral lengths in humans and both pig breeds were comparable as were estimated renal functions between both pig breeds. Discussion and Conclusion: Both landrace piglets and juvenile minipigs are suitable models for experimental pediatric urology as parameters did not differ between them. In addition, the anatomic parameters are comparable or smaller than in infants. This might facilitate translational research as technical failure is less likely in larger organs. Additional research is necessary to cover higher age ranges than those included in the present pilot study.

Background/purpose: Irreproducibility and missing translatability are major drawbacks in experimental animal studies. Hand-sewn anastomoses in oesophageal surgery are usually continuous, whereas those in experimental oesophageal surgery are widely performed using the simple interrupted technique. It has been implicated to be inferior in tolerating anastomotic tension, which we aimed to test in rats due to their importance as an animal model in oesophageal surgery. Methods: We determined linear breaking strengths for the native oesophagus (n = 10), the simple interrupted suture anastomosis (n = 11), and the simple stitch (n = 9) in 8-week old Sprague-Dawley rats. Experiments were powered to a margin of error of 10% around the results of exploratory investigations. The comparison of anastomotic resilience between native organ and simple interrupted suture anastomosis was a priori powered to 99%. Results: Native oesophagi sustained traction forces of 4.25 N (95% CI: 4.03-4.58 N), but the simple interrupted suture anastomosis had only 38.6% (Delta = -2.78 N, 95% CI: -2.46 to -3.11 N, p<.0001) of the resilience of native oesophagi. Conclusions: Oesophageal division and re-anastomosis markedly decreases resilience to traction forces compared to the native organ. This effect is even more pronounced in rats compared to other species and might impair transferability of results.

BACKGROUND:Anastomotic tension has repeatedly been associated with anastomotic leakages after esophagectomy for cancer or esophageal atresia repair. We therefore aimed to determine which anastomotic technique would come as close as possible to the native esophagus in sustaining traction forces. Constant traction for several minutes at esophageal remnants and large suture bites are also considered relevant in long-gap esophageal atresia repair. METHODS:Porcine esophagi were subjected to linear traction using a motorized horizontal test stand. We compared breaking strengths of native esophagi to simple continuous, simple interrupted, stapled, and barbed suture anastomoses. We also investigated the effects of suture bite length and phases of constant traction on breaking strengths and powered all experiments to at least 80% using exploratory investigations (n = 5 per group). RESULTS:Continuous suture anastomoses had a breaking strength comparable to native esophagi (Δ = -5.25 Newton, 95% confidence interval: -10.69 to 0.19 Newton, p = 0.058) and outperformed all other investigated anastomoses (Δ ≥14.01 Newton, p ≤ 0.02). Breaking strength correlated with suture bite length (R = 0.905) and predicted breaking strength for the simple stitch (adjusted R2 = 0.812, p < 0.0001), but not for anastomoses. Phases of incrementally increasing constant traction resulted in higher breaking strengths (Δ = 13.36 Newton, 95% confidence interval: 9.93 to 16.79 Newton, p < 0.0001) and higher length gain (Δ = 1.06 cm, 95% confidence interval: 0.65 to 1.48 cm, p < 0.0001) compared with controls. CONCLUSIONS:Only simple continuous anastomoses achieved the linear breaking strength of native tissue. Our study provides important insights in tolerance to traction forces, but its results have to be corroborated in living animals as anastomotic leakages are multifactorial processes.

Background Anastomotic tension has been linked to leakage and stenosis in esophageal surgery in both adults and children. We aimed to determine the effects of esophageal topography, operative technique, and anastomotic tension on esophageal blood flow. Materials and Methods We divided and reanastomosed the esophagi at the carinal level with increasing levels of anastomotic tension in piglets (n = 10) and sham controls (n = 4). We examined esophageal blood flow pre- and postoperatively using laser Doppler flowmetry at the anastomosis and two predetermined proximal and distal points. Blood flow in relation to distance from the anastomosis was examined by multivariate linear regression. Results Thoracotomy alone did not influence perfusion at the carinal level in shams (Δ = 3.13 laser Doppler units, 95% confidence interval: −3.4 to 9.7, p = 0.2686). We constructed a (F[5,134] = 6.34, p < 0.0001) multinomial regression model based on distance to the anastomotic site and pre-/postoperative measurements (adjusted R 2 = 0.1624). Tissue blood flow was higher distant to the carina, but lower postoperatively and not influenced by the tension resulting from the extent of resection (F[1, 8] = 1.134, p = 0.318). Conclusion Esophageal blood flow is higher at greater distances to the carinal level and hampered by esophageal division and reanastomosis. The extent of resection has less influence than previously assumed. Therefore, leakage and stenosis after esophageal anastomosis may not solely be caused by insufficient anastomotic blood flow.