Esophageal Biomechanics Revisited: A Tale of Tenacity, Anastomoses, and Suture Bite Lengths in Swine

Longitudinal Force Measurement and its Relationship to Technical Competence for Esophageal Anastomosis in a Thoracoscopic Esophageal Atresia/tracheo-esophageal Fistula Simulator

PURPOSE

Thoracoscopic esophageal atresia with tracheo-esophageal fistula (EA/TEF) repair requires the gentle manipulation of delicate tissue. Force sensors were attached to the upper and lower esophagus of a 3D-printed EA/TEF simulator to explore force parameters as markers of performance.

METHODS

Participants completed one intracorporeal suture between the anterior walls of upper and lower esophageal ends. Longitudinal force data were recorded at each end. A blinded pediatric surgeon marked attempt videos. Excessive force events, maximum tension, and force interquartile range (IQR) were measured. Data were reported as median (range) significance of p < 0.05.

RESULTS

17 participants of varying levels of experience performed the task. OSATS scores showed significant differences between experts and novices. Experts completed the task in a median time of 4 min. They used lower maximum tension, higher force IQR, and had fewer excess force events compared to the intermediate and novice groups.

DISCUSSION

The application of force was dependent on expertise with more skilled participants having fewer excess force events. The higher expert force IQR likely reflects the consistent tension needed for task completion. Analysis of force data may be an indicator of competence, and trainees may benefit from a thoracoscopic simulator which provides force data feedback.

LEVEL OF EVIDENCE

Not applicable.

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.

Pilonidal sinus disease on the rise: a one-third incidence increase in inpatients in 13 years with substantial regional variation in Germany

PURPOSE

Collective evidence from single-centre studies suggests an increasing incidence of pilonidal sinus disease in the last decades, but population-based data is scarce.

METHODS

We analysed administrative case-based principal diagnoses of pilonidal sinus disease and its surgical therapy between 2005 and 2017 in inpatients. Changes were addressed via linear regression.

RESULTS

The mean rate of inpatient episodes of pilonidal sinus disease per 100,000 men increased from 43 in 2005 to 56 in 2017. In females, the mean rate of inpatient episodes per 100,000 women rose from 14 in 2005 to 18 in 2017. In the whole population, for every case per 100,000 females, there were 3.1 cases per 100,000 males, but the numbers were highly variable between the age groups. There was considerable regional variation within Germany. Rates of inpatient episodes of pilonidal sinus disease were increasing in almost all age groups and both sexes by almost a third. Surgery was dominated by excision of pilonidal sinus without reconstructive procedures, such as flaps, whose share was around 13% of all procedures, despite recommendations of the national guidelines to prefer flap procedures.

CONCLUSION

Rates of inpatient episodes of pilonidal sinus disease in Germany rose across almost all age groups and both sexes with relevant regional variation. The underlying causative factors are unknown. Thus, patient-centred research is necessary to explore them. This should also take cases into account that are solely treated office-based in order to obtain a full-spectrum view of pilonidal sinus disease incidence rates.

A Continuous Suture Anastomosis Outperforms a Simple Interrupted Suture Anastomosis in Esophageal Elongation

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 100-120 kg), 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 (  = 4.47 cm, 95% confidence interval: 4.08-4.74 cm) outperformed the simple interrupted suture anastomosis in another 15 esophagi (  = 3.03 cm, 95% confidence interval: 2.59-3.43 cm) in length gain (Δ = 1.44 cm, 95% confidence interval: 0.87-2.01 cm, 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.

Laparoscopy for Abdominal Testes: Nationwide Analysis of German Routine Data

Introduction: Laparoscopy has been used for the evaluation of impalpable testes for more than 30 years. However, its use for intra-abdominal testes has never been evaluated in a population-based approach. Neither has the share of timely orchiopexies of intra-abdominal testes according to published guidelines. We aimed to provide this information by using nationwide administrative data for hospital reimbursements. Materials and Methods: We obtained data for procedures for exploration and orchiopexy of intra-abdominal testes in Germany from 2005 through 2018 and analyzed them with linear regression for the use of laparoscopy and timely repair. Results: In 2005, laparoscopy was already used in more than 60% of explorations, which composed 76% (95% confidence interval [CI]: 72 to 79) of children operated before their first birthday and 68% (95% CI: 65 to 70) of children up to 4 years of age. Throughout the study period, laparoscopy became increasingly popular for orchiopexy of intra-abdominal testes with a yearly increase of 1.8% (95% CI: 1.2 to 2.5, P < .001) in the first year of life and 1.3% (95% CI: 0.2 to 3.4, P < .001) until the age of 4. The share of patients treated before their first birthday increased yearly by 1.9% for explorations and 1.6% for orchiopexies (P < .001 for both) but did not exceed 30% in 2018. Conclusion: Laparoscopy is the method of choice for exploration of intra-abdominal testes and orchiopexy. In this study, more than 70% of boys were treated after their first birthday, thus not meeting the time limit set by guidelines.

Using simple interrupted suture anastomoses may impair translatability of experimental rodent oesophageal surgery

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% (Δ= -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.

Using multidimensional scaling in model choice for congenital oesophageal atresia: similarity analysis of human autopsy organ weights with those from a comparative assessment of Aachen Minipig and Pietrain piglets

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, q1* = 0.0083 and Δ = 11.4%, 95% CI: 5.1-17.6; p = 0.0025, q3* = 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.