Augmented Reality Registration System for Visualization of Skull Landmarks.

BACKGROUND: Augmented reality (AR) is an emerging technology in neurosurgery with the potential to become a strategic tool in the delivery of care and education for trainees. Advances in technology have demonstrated promising use for improving visualization and spatial awareness of critical neuroanatomic structures. In this report, we employ a novel AR registration system for the visualization and targeting of skull landmarks. METHODS: A markerless AR system was used to register 3-dimensional reconstructions of suture lines onto the head via a head-mounted display. Participants were required to identify craniometric points with and without AR assistance. Targeting error was measured as the Euclidian distance between the user-defined location and the true craniometric point on the subjects' heads. RESULTS: All participants successfully registered 3-dimensional reconstructions onto the subjects' heads. Targeting accuracy was significantly improved with AR (3.59 ± 1.29 mm). Across all target points, AR increased accuracy by an average of 19.96 ± 3.80 mm. Posttest surveys revealed that participants felt the technology increased their confidence in identifying landmarks (4.6/5) and that the technology will be useful for clinical care (4.2/5). CONCLUSIONS: While several areas of improvement and innovation can further enhance the use of AR in neurosurgery, this report demonstrates the feasibility of a markerless headset-based AR system for visualizing craniometric points on the skull. As the technology continues to advance, AR is expected to play an increasingly significant role in neurosurgery, transforming how surgeries are performed and improving patient care.

Implantation metastasis from sigmoid colon cancer to rectal anastomosis proved by whole exome sequencing and lineage inference for cancer heterogeneity and evolution analysis: Case report and literature review.

It was estimated that 70% of patients with colorectal cancer were found to have viable exfoliated malignant cells in adjacent intestinal lumen. Exfoliated malignant cells had been reported to implant on raw surfaces, such as polypectomy site, anal fissure, anal fistula, hemorrhoidectomy wound, and anastomotic suture line. Tumors at anastomosis could be classified into four groups: local recurrence, local manifestation of widespread metastasis, metachronous carcinogenesis, and implantation metastasis. However, all of the previous studies only reported the phenomena of implantation metastasis at anastomosis. No study had proved the origin of anastomotic metastasis by genomic analysis. In this study, a 43-year-old woman presented with persistent hematochezia was diagnosed as having severe mixed hemorrhoids. She was treated by procedure for prolapse and hemorrhoids (PPH), without receiving preoperative colonoscopy. Two months later, she was found to have sigmoid colon cancer by colonoscopy due to continuous hematochezia and received radical sigmoidectomy. Postoperative histological examination confirmed the lesion to be a moderately differentiated adenocarcinoma (pT3N1M0). Six months later, she presented with hematochezia again and colonoscopy revealed two tumors at the rectal anastomosis of PPH. Both tumors were confirmed to be moderately differentiated adenocarcinoma without lymph node and distant metastasis and were finally removed by transanal endoscopic microsurgery (TEM). Pathological examination, whole exome sequencing (WES), and Lineage Inference for Cancer Heterogeneity and Evolution (LICHeE) analysis demonstrated that the two tumors at the rectal anastomosis were probably implantation metastases arising from the previous sigmoid colon cancer. This is the first study to prove implantation metastasis from colon cancer to a distal anastomosis by WES and LICHeE analysis. Therefore, it is recommended to rule out colorectal cancer in proximal large bowel before performing surgery with a rectal anastomosis, such as PPH and anterior resection. For patients with a suspected implanted tumor, WES and LICHeE could be used to differentiate implantation metastasis from metachronous carcinogenesis.

Standardized suturing can prevent slackening or bursting suture lines in midline abdominal incisions and defects.

PURPOSE: Incisional hernias often follow open abdominal surgery. A small-stitch-small-bite suture might close the incision durably. We analyzed specific details of this closure technique and assessed their influence on the closure stability. METHODS: The effects of cyclic loads, simulating coughs were investigated on a bench test. We prepared porcine bellies in the median line and bovine flanks parallel to the muscle fibers with 15 cm long incisions. Then we punched round or rhomboid defects with a diameter of 5-10 cm into the center of the incision. Monomax® 2-0 and Maxon® 1 and 2-0 were used as suture materials. We tested the durability of the closure with pressure impacts of 210 mmHg repeated 425 times. Throughout the experiments, we modified the suturing technique, the surgeon, the tissue tension, the defect size and shape and the suture diameter. RESULTS: Standardizing the suture technique improved the durability of the closure significantly. Any other variations showed minor influences after standardization. All incisions with round defects up to 7.5 cm width withstood 425 impacts using standardized suturing. Unstandardized sutures failed in all cases. When closing an incision with a 10 cm wide defect, the tissues ruptured frequently next to the suture line. We defined criteria to standardize this suturing technique. For the first time, we developed a suture factor related to the durability of a sutured tissue closure. We integrated the suture factor into the concept of biomechanically durable repairs. CONCLUSIONS: Suturing the abdominal wall with a standardized suturing technique improves its durability significantly.

A polyurethane-based surgical adhesive for sealing blood vessel anastomoses-A feasibility study in pigs.

Peri- and postoperative anastomotic leakage from blood vessel anastomosis is a common and potentially life-threatening complication. As an adjunctive therapy providing an additional layer of safety, a new biodegradable, polyurethane-based adhesive was developed. It consists of two components: an isocyanate-functionalized prepolymer and an amino-based curing agent. The adhesive was investigated in a porcine animal model to seal sutured blood vessel anastomoses of arteries, veins, aortas and prosthetic aortic graft replacements. The material-determined properties of the adhesive like viscosity, processing and polymerization time as well as bonding strength were well suited for this application. The adhesive stopped perioperative suture-line bleedings and stayed on all anastomoses until sacrifice. Hematological and serological inflammation marker assessments were unobtrusive. The histological evaluation showed a mild to moderate local tissue reaction to the adhesive constituting a physiological, non-adverse tissue-biomaterial interaction. The adhesive did not interfere with vascular wound healing. The adhesive demonstrated to be suitable to improve the outcome of cardiovascular surgeries by securing the classical sutured anastomoses in a fast, easy and safe manner. However, further studies are required to quantitatively evaluate efficacy in terms of anastomotic leakage prevention as well as long-term tissue compatibility and degradation.

Cardiocutaneous fistula secondary to left ventricular pseudo-aneurysm rupture.

Cardiocutaneous fistula (CF) is a potentially serious and catastrophic complication. Infection the suture line after left ventricular aneurysm repair, presenting with the CF. We present an unusual case of CF due to staphylococcus infection 6 months after repair of a myocardial rupture secondary to dehiscence repair.

The effect of postoperative CPAP use on anastomotic and staple line leakage after bariatric surgery.

PURPOSE: Almost two-thirds of the population undergoing bariatric surgery (BS) suffers from obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) is the standard treatment for moderate to severe OSA and is recommended in patients undergoing BS perioperatively. A severe and dreaded complication after BS is anastomotic leakage. There is theoretical concern that perioperative CPAP use may result in increased distension of the gastrointestinal tract and increase the risk of developing an anastomotic leakage. The aim of this study was to evaluate the effect of postoperative CPAP use on the risk of developing anastomotic leakages after BS. METHODS: Retrospectively, all patients from a single bariatric center who underwent BS from November 2007 to August 2019 were included. Presence and severity of OSA were determined using poly(somno)graphy. To evaluate the effect of postoperative CPAP use on anastomotic leakage, a multivariable logistic regression analysis was performed. RESULTS: A total of 4052 patients were included, with OSA being diagnosed in 62%. Overall, 970 patients (24%) used CPAP after BS. Anastomotic leakage occurred in 64 (1.6%) patients after BS. Leakage rate was 1.3% in non-CPAP group versus 2.5% in CPAP group (p = 0.01). CPAP use was associated with anastomotic leakage; however, after adjustment, CPAP use was not an independent predictor (OR = 1.40, 95% CI 0.60-3.28, p = 0.44). CONCLUSION: There is no independent relation between postoperative CPAP use and anastomotic leakage after BS. Only revision surgery was an independent predictor of anastomotic leakage.

In vitro and in vivo study of novel antimicrobial gellan-polylysine polyion complex fibers as suture materials.

GELLAN GUM: and gellan-derived materials have never been used for suture materials due to their lack of strength and toughness. In this study, gellan and ε-polylysine formed a polyion complex in water solution, and the complex was transformed into fibers via wet-spinning. The fibers were bundled, twisted, and elongated, and the resultant twisted and elongated yarn (GPF) had a diameter of 97.53-103.76 µm and tensile strength of 4 N. The swelling ratio of GPF was 165.55%-183.23% in weight in normal saline, and the linear density was 2.84-3.31 g/km. GPF was tested using agar diffusion tests and it was found that the fibers had good antibacterial activity against Escherichia coli and Staphylococcus epidermidis. In weight loss experiments, GPF was found to be undegradable in normal saline and slightly degradable (residual weight ratio was 83.2 ± 1.2%) in simulated body fluid with trypsin within 7 days. Moreover, GPF showed no cytotoxicity toward BV-2 cells in cytotoxity tests with CCK8 and no hemolysis in hemolytic tests with fresh C57 mice blood. Finally, GPF was assessed using mouse dorsal cross-cutting model, and none of the mice that were tested with GPF showed infection or rejection reaction. Therefore, GPF is a promising suture material, and this study provides a new development direction for the application of gellan materials with improved mechanical properties.

Exfoliated cancer cells during intersphincteric resection for very low rectal cancer.

PURPOSE: To investigate the frequency of exfoliated cancer cells and the efficacy of rectal washout during intersphincteric resection (ISR) in patients not receiving chemoradiotherapy (CRT) for very low rectal cancer. METHOD: The subjects of this prospective study were 16 consecutive patients who underwent ISR without CRT for very low rectal cancer. Brushing cytology of the posterior anorectal wall was performed twice in each step of the ISR procedure and the samples were sent for blind cytological examination to identify exfoliated cancer cells. RESULTS: Exfoliated cancer cells were identified in 9 of 13 patients (69%) preoperatively. The number of cancer cells identified after abdominal total mesorectal dissection decreased significantly from 94% (15/16) to 25% (4/16) after transanal irrigation with 2000 mL saline (p < 0.001). No cancer cells were identified after swabbing the anal wall following transanal dissection with purse-string closure of the distal stump. No suture-line recurrence was found during a median follow-up duration of 6 years. CONCLUSION: Exfoliated cancer cells, confirmed in 94% of patients after total mesorectal excision, could be eliminated by performing rectal irrigation after clamping the rectum proximal to the tumor and swabbing the anorectal wall during ISR.

Heterochronous Suture Line Recurrences in the Jejunal Pouch following Total Gastrectomy for Stage II Gastric Cancer: A Case Report and Literature Review.

We report the case of a 65-year-old male who developed heterochronous local recurrences of gastric cancer in the jejunal pouch (J-pouch) four times after total gastrectomy. He underwent total gastrectomy, J-pouch, and Roux-en-Y reconstruction for stage II gastric cancer in 2005. Four local recurrences appeared on the esophago-jejunal anastomosis, the suture line within the pouch, the esophago-jejunal anastomosis, and the anastomosis between the jejunum and Y-loop, which were resected by partial excision or endoscopic submucosal dissection. Suture line recurrence of gastric cancer is rare. The common features for each recurrence included the surgically negative resection margins, observation of the same histopathological subtype, absence of remote metastasis or peritoneal seeding, and the recurrence on the anastomotic suture line, suggesting that the cause of recurrence was the implantation of exfoliated cancer cells probably in the suture line. However, there is no established procedure for preventing implantation recurrence currently, the effectiveness of lumen lavage is suggested.

Double mattress suture lines for valve-sparing aortic root replacement.

Valve sparing aortic root replacement remains a complex procedure despite various improvements that have been made to this operation. Specifically, a hemostatic proximal anastomosis is one of the most important factors for successful completion of the operation without complication. Here we describe a double mattress suture line technique, which facilitates a secure and hemostatic proximal suture line.

Short- and long-term outcomes of endoscopic submucosal dissection for early gastric cancer in the remnant stomach after gastrectomy.

BACKGROUND: Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in the remnant stomach is a minimally invasive treatment. Few studies compared the technical difficulty of ESD involving the suture line and anastomosis, and information on long-term outcomes is insufficient. This study aimed to elucidate the short- and long-term outcomes of ESD for EGC in the remnant stomach. METHODS: We investigated patients who underwent ESD for EGC in the remnant stomach between September 2002 and March 2016. Clinicopathological data were retrieved to assess en bloc resection rates, complications, and long-term outcomes including overall survival and cause-specific survival. RESULTS: A total of 136 consecutive patients with 165 lesions resected by 157 ESD procedures were retrospectively evaluated. The en bloc resection rate was 95.5%. Complications included 16 intraoperative perforations (10.2%), 2 delayed perforations (1.3%), and 15 delayed bleeding (9.6%), which were successfully treated with endoscopy. The en bloc resection rate was significantly higher in the suture line group (100%) and the non-anastomosis or suture line group (98.8%) than in the anastomosis group (82.9%). However, the intraoperative perforation rate was significantly higher in the anastomosis group (31.4%) than in other groups. The 5-year overall and cause-specific survival rates were 88.4% and 97.6%, respectively, during a median follow-up period of 50.7 months (interquartile range 30.8-91.3). CONCLUSIONS: The long-term outcomes of ESD for EGC in the remnant stomach were favorable. However, ESD involving the anastomosis was a technically demanding procedure due to the low en bloc resection rate and high perforation rate.

Presence of colon carcinoma cells at the resection line may cause recurrence following stapling anastomosis.

BACKGROUND/OBJECTIVE: The presence of carcinoma cells in the suture line may result in local recurrence. The purpose of this study was to assess whether carcinoma cells were present along the resection line where the distal clamp was applied. METHODS: During surgery, the rectum was clamped at least 3 cm distal to the palpable margin of the tumor mass. The rectum was divided distal and proximal to the clamp. The tissue inside the clamp was rinsed with normal saline, and the irrigation solution was sent for cytologic examination. RESULTS: In 134 patients with carcinoma of the rectosigmoid colon or rectum, we found four (3.0%) cases of positive cytology, and five cases (3.7%) with cytology indicting the presence of atypical cells highly suspicious for malignancy. It was postulated that the trapping of cancer cells in a double-staple anastomosis line may have resulted in local recurrence. CONCLUSION: This study indicates that double staple-line recurrence is related to the shedding of cancer cells during dissection and clamping.

Influence of continuous positive airway pressure on postoperative leakage in bariatric surgery.

BACKGROUND: Obstructive sleep apnea (OSA) affects two third of morbidly obese individuals undergoing bariatric surgery. Perioperative usage of continuous positive airway pressure (CPAP) is advised for moderately and severe OSA to avoid respiratory failure and cardiac events. CPAP increases the air pressure in the upper airway, but also may elevate the air pressure in the esophagus and stomach. Concern exists that this predisposes to mechanical stress resulting in suture or staple line disruption (further referred to as suture line disruption). OBJECTIVES: To evaluate whether perioperative CPAP usage is associated with an increased risk of suture line disruption after bariatric surgery. SETTING: Obesity Center Amsterdam, OLVG-west, Amsterdam, the Netherlands. METHODS: All patients who underwent bariatric surgery including a suture line were eligible for inclusion. Only patients with information regarding OSA severity as defined by the apnea-hypopnea-index and postoperative CPAP usage were included. RESULTS: From November 2007 to August 2016, postoperative CPAP status was documented in 2135 patients: 497 (23.3%) used CPAP postoperatively, whereas 1638 (76.7%) used no CPAP. Mean body mass index was 44.1 kg/m2 (standard deviation 6.6). Suture line disruption occurred in 25 patients (1.2%). The leakage rate was not associated with CPAP usage (8 [1.6%] in CPAP group versus 17 [1%] in non-CPAP group, P = .300). CPAP was no risk factor for suture line disruption in multivariable analysis as well. CONCLUSION: Postoperative CPAP does not appear to increase the risk of suture line disruption in bariatric surgery. CPAP is recommended in all patients with moderate or severe OSA who undergo bariatric surgery.

Positive detection of exfoliated colon cancer cells on linear stapler cartridges was associated with depth of tumor invasion and preoperative bowel preparation in colon cancer.

BACKGROUND: The aim of this study was to investigate exfoliated cancer cells (ECCs) on linear stapler cartridges used for anastomotic sites in colon cancer. METHODS: We prospectively analyzed ECCs on linear stapler cartridges used for anastomosis in 100 colon cancer patients who underwent colectomy. Having completed the functional end-to-end anastomosis, the linear stapler cartridges were irrigated with saline, which was collected for cytological examination and cytological diagnoses were made by board-certified pathologists based on Papanicolaou staining. RESULTS: The detection rate of ECCs on the linear stapler cartridges was 20 %. Positive detection of ECCs was significantly associated with depth of tumor invasion (p = 0.012) and preoperative bowel preparation (p = 0.003). There were no marked differences between ECC-positive and ECC-negative groups in terms of the operation methods, tumor location, histopathological classification, and surgical margins. CONCLUSIONS: Since ECCs were identified on the cartridge of the linear stapler used for anastomosis, preoperative mechanical bowel preparation using polyethylene glycol solution and cleansing at anastomotic sites using tumoricidal agents before anastomosis may be necessary to decrease ECCs in advanced colon cancer.

Tailored therapy for different presentations of chronic pain after stapled hemorrhoidopexy.

BACKGROUND: As stapled hemorrhoidopexy (SH) becomes more widely used, we see more patients with chronic postoperative anal pain after this surgery. Its presentation is variable and difficult to treat. The aim of our study was to investigate the impact of chronic anal pain after SH and whether tailored therapy was likely to achieve a favorable outcome. METHODS: We retrospectively analyzed 31 consecutive patients with chronic anal pain who had undergone SH in other hospitals and were referred to our institutions. Depending on the type of pain, unrelated (at rest) or related to defecation, two groups of patients were identified. Moreover, the mean distance of the staple line from the anal verge was calculated in both groups. Treatments included: topical nifedipine, local anesthetic and steroid infiltration, removal of retained staples, anal dilation, and scar excision with mucosal suturing. A visual analog scale (VAS) was used to compare pain at baseline, postoperatively, and in the follow-up. This mean difference of the VAS score between stages was always used as the main outcome measure, depending on the type of presentation, type of pain, and type of treatment. Treatment response was defined as a 50 % decrease of VAS from baseline. RESULTS: There were 22 males and 9 females. The overall median age was 43 years (range 21-62 years). On digital examination and proctoscopy, 15 (48 %) patients had inflammatory changes, 19 (61 %) patients had staple retention, 8 (26 %) patients had anorectal stenosis, and 30 (97 %) patients had scar tissue. All patients had one or more of the following treatments listed from the least to most invasive: topical nifedipine in 12 (39 %) patients, anal dilation in 6 (19 %) patients, anesthetic and steroid infiltration in 18 (58 %) patients, removal of staples in 10 (32 %) patients, and scar excision in 18 (58 %) patients. The mean VAS score at baseline was 6.100, ± 1.953 SD, which dropped significantly after treatment to 1.733, ± 1.658 SD (p < 0.001) and remained low at follow-up (1.741 ± SD 1.251; p < 0.743). In patients with pain at rest (n = 20, 65 %), the symptoms improved in 19 (95 %) patients, while the VAS score decreased from 5.552 ± 2.115 SD to 1.457 ± 1.440 SD (95 % CI 3.217-4.964; p < 0.001). In patients with post-evacuation pain (n = 11, 35 %), the symptoms improved in 11 (100 %) patients, while the VAS score decreased from 6.429 ± 1.835 SD to 1.891 ± 1.792 SD (95 % CI 3.784-5.269; p < 0.001). Rating of response based on presentation was 90.0 % (0.9/10) after treatment of staple retention, which led to a significant decrease in the mean VAS score from 6.304 ± 1.845 SD to 1.782 ± 1.731 SD (95 % CI 3.859-5.185; p < 0.001). Anal stenosis was successfully treated in 100.0 % (n = 8/8) of cases with the mean VAS score dropping from 6.500 ± 1.309 SD to 2.125 ± 1.808 SD (95 % CI 2.831-5.919; p < 0.001). Anal inflammation improved in 60.0 % (n = 9/15) of patients and the mean VAS score dropped from 6.006 ± 2.138 SD to 1.542 ± 1.457 SD (95 % CI 3.217-4.964; p < 0.001). The response after scar tissue treatment was 94 % (n = 17/18) of patients with a mean VAS decreasing from 6.117 ± 2.006 SD to 1.712 ± 1.697 SD (95 % CI 3.812-4.974; p < 0.001). Success for topical nifedipine was between 13 and 25 % of patients depending on the clinical presentation. Anal dilation was successful in 75 % of patients, while Anesthetic and steroid infiltration in 23-54 % of patients depending on the clinical presentation. Staple removal was successful in 77 % of patients, and scar excision with mucosal suturing in 94 % of patients. CONCLUSIONS: Our retrospective study suggests that most patients with chronic anal pain after SH may be cured with treatment by applying a stepwise approach from the least to the most invasive treatment.

The Effect of Short Nerve Grafts in Series on Axonal Regeneration Across Isografts or Acellular Nerve Allografts.

PURPOSE: To evaluate the regenerative effect of the additional suture line when using either isografts (ISOs) or acellular nerve allografts (ANAs) placed end-to-end to span a short gap in a rat model. METHODS: Rat sciatic nerves were transected and repaired with 2-cm nerve grafts (ISO or ANA). The grafts were 2 cm in length or a 1-cm segment was connected end-to-end to a 1-cm segment to yield a 2-cm length. At 8 weeks, extensor digitorum longus (EDL) muscle force and mass were measured. Nerves were harvested for histomorphometry. In a separate parallel study, the nerves were harvested 2 weeks following graft implantation to assess gene expression changes. RESULTS: All grafts demonstrated regeneration across the 2-cm segment(s). The additional suture line did not result in statistical differences in the number of myelinated nerve fibers that reached the distal nerve. However, when the graft types were compared, there was a significant decrease in nerve fibers in the ANA groups. The EDL muscle mass was significantly greater by using nerve ISOs compared with ANAs, regardless of an additional suture line, but there were no statistical differences noted in EDL muscle force. Gene expression analysis did not differ owing to an additional suture line. CONCLUSIONS: Minimal axonal loss and no functional deficits were identified with an additional suture line in this rodent short nerve gap model. CLINICAL RELEVANCE: Placing nerve grafts in series is a viable option for treating short nerve gaps; however, the use of autografts remains preferable over the use of ANAs.

Suture Line Response of End-to-Side Anastomosis: A Stress Concentration Methodology.

End-to-side vascular anastomosis has a considerable complexity regarding the suturing of the juncture line between the artery and the graft. The present study proposes a stress-concentration methodology for the prediction of the stress distribution at the juncture line, aiming to provide generic expressions describing the response of an end-to-side anastomosis. The proposed methodology is based on general results obtained from the analysis of pipe connections, a topic that has been investigated in recent years in the field of offshore structural engineering. A key aspect for implementing the stress-concentration-factor approach is the recognition that the axial load due to pressure and flow dynamics exerted along the graft axis controls the "hot spots" on the juncture line, which in turn affects the mechanical response of the sutures. Several parameters, identified to influence the suture line response, are introduced in closed-form expressions for the suture line response calculations. The obtained results compare favorably with finite element results published in the literature. The proposed model predicts analytically the suture line response of end-to-side anastomosis, while capturing the influence of and interdependence among the problem parameters. Lower values of the graft radius, the distance between sequential stitches, and the intersecting angle between the artery and the graft are some of the key parameters that reduce the suture line response. The findings of this study are broad in scope and potentially applicable to improving the end-to-side anastomosis technique through improved functionality of the sutures and optimal selection of materials and anastomosis angle.

Analytical Side-to-Side Related Anastomotic Strategies and Artery Patching.

Suture line stress concentration and intimal hyperplasia are related to the long-term complications of end-toside and side-to-side anastomosis. Several factors, such as hemodynamic effects, biological activities and the mechanical properties of the blood vessels, are identified to influence the problem. Yet, it is not completely clear which are the factors that influence most the long-term complications and in what specific way. This study aims to examine if elastic (compliance) mismatch increases the stress concentration and intimal thickening at the suture line. Better compliance may be obtained by using grafts with similar mechanical properties to the host artery or by anastomosis techniques that utilize vein patches and cuffs (Taylor-patch and Miller-cuff anastomosis). The anastomosis model used in this study is a circular cylindrical system consisting of two semi-cylinders, interconnected by two hinges. The internal blood pressure is applied on the arterial walls. The static and dynamic responses are analytically derived in terms of radial and tangential displacements, internal forces and strains of the two blood vessels and rotation of their cross-section. Results suggest that increased elastic mismatch between the artery and the graft may promote elevated intimal thickening due to large incompatible angles at the junction, whereas there is no correlation between elastic mismatch and elevated stress concentration at the suture line. Another interesting application of the present model is the patching of arteries as applied in carotid endarterectomy.