Evaluation of staple line reinforcement after partial gastrectomy closure in an ex vivo canine model.

OBJECTIVE: To determine the influence of stapling on leakage pressures after canine partial gastrectomy. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Gastric specimens from 24 adult canine cadavers. METHODS: Partial gastrectomy constructs were assigned to one of three closure techniques (n = 8 per group): group 1, stapled closure with a 90-mm thoracoabdominal stapling device and a 4.8-mm staple cartridge; group 2, hand-sewn double-layer inverting suture closure with 3-0 glycomer 631; and group 3, staple line reinforcement with an inverting Cushing suture pattern. Leakage and pressure testing were performed. Initial leakage pressure (ILP), maximal leakage pressure (MLP), and leakage location were recorded. Significance was set at P < .05. RESULTS: Placement of a Cushing suture (group 3) increased ILP and MLP by 3.2-fold and 2.8-fold, respectively, compared with stapled closures alone (P < .001). Constructs closed with double-layer suture closure reached ILP and MLP 4.5-fold and threefold greater, respectively, compared with those with stapled closures alone (P < .001). Maximal leakage pressure did not differ between groups 2 and 3 (P = .14). Leakage occurred from the inverting suture line in all constructs of groups 2 and 3 and from staple holes in six of eight group 1 constructs. CONCLUSION: Double-layer suture closure of canine partial gastrectomies achieved superior biomechanical properties compared with stapled closure techniques. Reinforcing staple closures with an inverting suture line improved resistance to leakage. CLINICAL SIGNIFICANCE: Reinforcing single-layer closure of partial gastrectomies with an inverting Cushing pattern is recommended to improve resistance to leakage. In vivo investigation is warranted to evaluate influence of closure technique on gastric healing, postoperative stasis, ischemic injury, and postoperative dehiscence.

Biomechanical comparison of three epitendinous suture patterns as adjuncts to a core locking loop suture for repair of canine flexor tendon injuries.

OBJECTIVE: To determine the effects of different epitendinous sutures (ES) in addition to core locking-loop (LL) sutures on the mechanical properties and gap formation in a canine cadaveric tendon model. STUDY DESIGN: Experimental, ex vivo, biomechanical study. SAMPLE POPULATION: Seventy-two cadaveric superficial digital flexor tendon specimens. METHODS: Superficial digital flexor tendon specimens were divided into four groups (n = 18): sharply transected and repaired with LL, LL + simple continuous ES, LL + Silfverskiöld cross-stitch ES, and LL + interlocking horizontal mattress ES. Constructs were loaded to monotonic failure. Failure modes, gapping, yield, peak, and failure forces were analyzed. Significance was set at P < .05. RESULTS: Yield, peak, and failure forces increased by 2.5-fold, two-fold, and twofold, respectively when ES groups were compared with core LL suture patterns alone (P < .0001). Resistance to 1- and 3-mm gap formation was greater in ES groups compared with core LL constructs alone (P < .0001). No differences in yield, peak, failure force, or gapping were observed among ES patterns (P > .827). CONCLUSION: Adding an ES reduced gap formation and increased yield, peak, and failure forces of tenorrhaphies. No difference was detected between the epitendinous patterns tested in this study. CLINICAL SIGNIFICANCE: The addition of an ES seems more relevant than the specific type of pattern to improve the biomechanical properties of flexor tendon repairs. In vivo studies are warranted to determine the biological implications of the patterns tested here.

Comparison between optical coherence tomographic and histopathologic appearances of artifacts caused by common surgical conditions and instrumentation.

OBJECTIVE: To document the appearance of artifacts created by commonly encountered surgical conditions and instrumentation on optical coherence tomography (OCT) and to compare these findings with histopathology. STUDY DESIGN: Ex vivo study. ANIMALS: Five canine cadavers. METHODS: Skin, subcutaneous fat, skeletal muscle, and fascia samples were obtained from fresh canine cadavers. Blood pooling, hemostatic crushing, scalpel blade cut, monopolar electrosurgery, bipolar vessel sealing device, and ultrasonic energy surgical artifacts were induced on each tissue type. Each specimen was imaged with OCT and subsequently histologically processed. RESULTS: Most surgical instrumentation used for tumor excision created a high-scattering region with local architectural disruption. Blood pooling was visible as a high-scattering layer overlying tissue with normal architecture. Only the scalpel blade created a focal, low-scattering area representing a sharply demarcated cut within the tissue distinct from the appearance of other instrumentation. CONCLUSION: Common surgical instruments and conditions encountered during tumor excision produced high-scattering OCT artifacts in tissues commonly seen at surgical margins. CLINICAL SIGNIFICANCE: The clinical value of OCT hinges on the ability of personnel to interpret this novel imaging and recognize artifacts. Defining and describing the appearance of common surgical artifacts provides a foundation to create image libraries with known histological and OCT interpretation, ultimately improving the diagnostic accuracy of OCT for assessment of surgical margins.

Segmental mandibulectomy as a novel adjunct management strategy for the treatment of an advanced cholesteatoma in a dog.

A 6-year-old spayed female Labrador retriever dog was evaluated for trismus and peripheral vestibular syndrome. Computed tomography (CT) revealed a mass arising from the tympanic bulla consistent with a cholesteatoma. A total ear canal ablation, bulla osteotomy, and adjunct segmental mandibulectomy were performed. Re-evaluation 2 weeks after surgery revealed no neurologic abnormalities, normal jaw range of motion, and no discomfort. Despite concern for recurrence of cholesteatoma based on CT imaging performed 33 months after surgery, repeat surgical intervention was not pursued as the owner considered the dog's comfort level to be satisfactory. The patient continued to do well for the 42-month follow-up period.

Mandibulectomie segmentaire comme nouvelle stratégie de gestion complémentaire pour le traitement d'un cholestéatome avancé chez un chien. Une femelle Labrador retriever de 6 ans stérilisée a été évaluée pour du trismus et un syndrome vestibulaire périphérique. La tomodensitométrie a révélé une masse issue de la bulle tympanique, compatible avec un cholestéatome. Une ablation totale du conduit auditif, une ostéotomie de la bulle et une mandibulectomie segmentaire complémentaire ont été réalisées. La réévaluation deux semaines après l'opération n'a révélé aucune anomalie neurologique, une amplitude de mouvement normale de la mâchoire et aucun inconfort. Malgré l'inquiétude suscitée par la récurrence du cholestéatome sur la base d'une tomodensitométrie réalisée 33 mois après la chirurgie, aucune nouvelle intervention chirurgicale n'a été envisagée, le propriétaire ayant estimé que le niveau de confort du chien était satisfaisant. La patiente a continué à bien se porter pendant la période de suivi de 42 mois.(Traduit par les auteurs).

Acellular fish skin grafts for the management of wounds in dogs and cats: 17 cases (2019-2021).

OBJECTIVE: To report the clinical outcomes of the use of acellular fish skin grafts (FSGs) for the management of complex soft tissue wounds of various etiologies in dogs and cats. ANIMALS: 13 dogs and 4 cats with complex wounds treated with FSGs between February 2019 and March 2021. PROCEDURES: Medical records were reviewed for information regarding cause, location, size of the wound, management techniques, complications, and clinical outcomes. RESULTS: In dogs, the number of FSG applications ranged from 1 to 4 (median, 2 graft applications). The time between each application ranged from 4 to 21 days (median, 9.5 days). Time to application of the first FSG ranged from 9 to 210 days (median, 19 days). Wounds closed by second-intention healing following the first fish skin application between 26 and 145 days (median, 71 days; n = 12). In cats, 1 or 2 FSGs were used, and the wounds of 3 of 4 cats healed completely by secondary intention. The wounds of 1 dog and 1 cat did not heal. There were no adverse events attributed to the use of the FSGs. CLINICAL RELEVANCE: For dogs and cats of the present study, complete healing of most wounds occurred with the use of FSGs, the application of which did not require special training, instruments, or bandage materials.

Optical coherence tomography imaging of excised canine apocrine gland anal sac adenocarcinoma tumours.

Optical coherence tomography (OCT) is an optical imaging modality that has been investigated for real-time surgical margin evaluation in human breast cancer patients. Previous veterinary OCT studies have been limited to surgical margin imaging for soft tissue sarcoma (STS) tumours. To the authors knowledge, OCT has never been used to characterize or evaluate other types of neoplasia in dogs. The goal of this study was to characterize the OCT imaging appearance of apocrine gland anal sac adenocarcinoma (AGASACA) in excised ex vivo specimens from five client-owned dogs. All excised tissue surgical margins were imaged using a clinical spectral domain OCT system and two to four areas suspicious for incomplete surgical margins were selected. These areas were inked and sections were trimmed for histopathology. This enabled OCT imaging from each area of interest to be compared with corresponding H&E stained histology imaging from the same location. OCT was able to identify the presence of AGASACA at or within 1 mm of the surgical margin in all areas of interest. AGASACA, similar to the previously described canine STS, generated a dense, highly scattering image without any specific textural architecture. This study was able to validate the ability of OCT to accurately identify another type of tumour presence at or close to the surgical margin in the dog. Further study is needed to assess OCT accuracy at identifying other tumour types in dogs to understand its potential clinical applications.

The feasibility and utility of optical coherence tomography directed histopathology for surgical margin assessment of canine mast cell tumours.

Histopathologic surgical margin assessment in veterinary patients is an imprecise science with assessment limited to a small proportion of the surgical margin due to time and finances. Incomplete excision of canine mast cell tumours (MCTs) alters treatment recommendations and prognosis. Optical coherence tomography (OCT) is a novel imaging modality that has been reported in a single veterinary study for surgical margin assessment. Twenty-five dogs with 34 MCTs were enrolled in a prospective pilot-study to assess the imaging characteristics of canine MCTs with OCT and to evaluate the feasibility and utility of OCT-guided histopathology. All dogs underwent routine surgical excision of MCTs. OCT imaging was used to assess the entire surgical margin prior to placement in formalin. Either normal areas or areas suspected of incomplete MCT excision were inked. Standard histopathologic sectioning and tangential sectioning of inked areas were performed and compared to OCT results. OCT identified MCT near the surgical margin in 10 of 26 specimens (38.4%). Four specimens suspicious for incomplete margins on OCT had incomplete MCT excision that was missed on standard histopathologic sectioning. Six specimens had OCT-guided sections taken as suspicious, which did not show MCT on histopathology. OCT-guided pathology sections were able to detect incompletely excised MCT near the surgical margin with a sensitivity of 90% and specificity of 56.2% in this preliminary study. OCT imaging shows promise for guiding pathologists to areas of interest to improve the diagnostic accuracy of surgical margin assessment in excised canine MCTs.

Influence of Interlocking Horizontal Mattress Epitendinous Suture Placement on Tendinous Biomechanical Properties in a Canine Common Calcaneal Laceration Model.

OBJECTIVE: This article evaluates the effect of an interlocking horizontal mattress epitendinous suture (IHMES) in addition to a three-loop pulley (3LP) core suture for canine tendon repair. STUDY DESIGN: Twenty-eight cadaveric common calcaneal tendons were randomized, sharply transected and repaired with either a 3LP or 3LP + IHMES. Tensile loads required to create a 1- and 3-mm gap, yield, peak and failure loads, and mode of failure were analysed. Significance was set at p < 0.05. RESULTS: Mean ± standard deviation yield and failure force for 3LP + IHMES was 178.0 ± 45.3 N and 242.1 ± 47.8 N, respectively, which was significantly greater compared with 3LP alone, 97.9 ± 36.2 N and 119.3 ± 35.6 N (p < 0.0001). Occurrence of 3-mm gap formation was significantly less in the 3LP + IHMES group (p < 0.013). Mode of failure was significantly different between the groups (p < 0.001) with 3LP + IMHES patterns failing by suture breakage (13/14) compared with suture pull-through in the 3LP (11/14). CONCLUSION: Addition of an epitendinous suture pattern significantly reduced gap formation between tendon ends and significantly increased loads at yield (1.8 × ), peak (2.0 × ) and failure (2.0 × ) force of repairs. Use of an epitendinous suture should be considered to significantly increase biomechanical strength of repairs; however, further in vivo testing is necessary to evaluate its effect on tendinous blood supply.

Effect of bite distance of an epitendinous suture from the repair site on the tensile strength of canine tendon constructs.

OBJECTIVE: To evaluate effects of bite distance of an interlocking horizontal mattress epitendinous suture (IHMES) from the repair site on tensile strength of canine tendon repairs. SAMPLE: 72 canine cadaveric superficial digital flexor tendons (SDFTs). PROCEDURES: Transverse tenotomy was performed, and SDFTs were repaired with a locking-loop construct (LL construct) or 3 LL constructs with IHMES suture bites placed 5 (LL + 5ES construct), 10 (LL + 10ES construct), or 15 (LL + 15ES construct) mm from the transection site (18 SDFTs/group). Constructs were loaded to failure. Load at 1- and 3-mm gapping, yield force, failure load, and failure mode were evaluated. RESULTS: Mean ± SD yield force and failure load for LL constructs were significantly lower than for IHMES constructs. Load at 1- and 3-mm gapping was significantly higher for IHMES constructs. Increasing the bite distance significantly increased construct strength (134.4 ± 26.1 N, 151.0 ± 16.8 N, and 182.1 ± 23.6 N for LL + 5ES, LL + 10ES, and LL + 15ES constructs, respectively), compared with strength for the LL construct. Failure mode differed significantly among constructs when an IHMES was used. CONCLUSIONS AND CLINICAL RELEVANCE: Addition of an IHMES to an LL construct led to increased ultimate tensile strength by 2.5 times and significantly reduced gap formation. Increasing the IHMES bite distance increased yield force by 2.1, 2.3, and 2.7 times for bites placed 5, 10, and 15 mm from the tenotomy, respectively. Positioning an IHMES at a greater distance from the repair site provided superior biomechanical strength for tendon repairs in dogs.

Minimally invasive treatment of mesenteric arterioportal fistulas in two dogs.

CASE DESCRIPTION Two Pembroke Welsh Corgis with gastrointestinal signs including inappetence, diarrhea, lethargy, and hypersalivation were referred for evaluation. CLINICAL FINDINGS Diagnostic testing included abdominal ultrasonography and CT angiography. One patient had a cranial mesenteric artery-to-mesenteric vein fistula with multiple acquired extrahepatic portosystemic shunts. The second patient had both cranial and caudal mesenteric artery-to-mesenteric vein fistulas and multiple acquired extrahepatic portosystemic shunts. TREATMENT AND OUTCOME Both patients underwent minimally invasive coil embolization of the mesenteric arterioportal fistulas, with complete occlusion confirmed by means of angiography at procedure completion. Clinical outcome approximately 1 year after treatment was assessed as fair to good because of recurrence of clinical signs that required medical management in 1 dog and some persistent serum biochemical abnormalities. CLINICAL RELEVANCE Outcome for the 2 patients described suggested that coil embolization may be a feasible and effective minimally invasive technique for the treatment of mesenteric arterioportal fistulas in dogs. However, further investigation of the potential for chronic hepatic disease in patients with a history of acquired portosystemic shunts is warranted.