Evaluation of the in vitro performance of the double forwarder knot, compared to square and surgeon's knots using large gauge suture.

OBJECTIVE: The aim of the study was to evaluate the strength and size of the double forwarder (DF) knot in 2 and 3 USP polyglactin 910 when used to form a ligature and to compare the knot holding capacity (KHC), size and weight of the DF knot to surgeon's (SU) and square (SQ) knots with varying numbers of throws. STUDY DESIGN: Laboratory study. STUDY POPULATION: Knotted suture. METHODS: Knots were tied using 2 and 3 USP polyglactin 910 and tested on a universal testing machine under linear tension. Mode of failure and (KHC) were recorded. Knot volume and weight were determined by digital micrometer and balance. KHC, size, and weight between knot type, number of throws, and suture type and size were compared using ANOVA testing, with p < .05 as significant. RESULTS: In both suture types, DF knots had a higher KHC than SQ/SU knots (p < .004), with the exception of SU knots with 6-8 throws in 3 USP polyglactin 910 (p > .42). All DF knots failed by suture breakage at the knot, as did all SQ/SU knots with >6 throws. DF knots in 2 and 3 USP polyglactin 910 were larger and heavier than SQ and SU knots when the same number of throws was applied (p < .003). CONCLUSION: Self-locking DF knots provided increased strength compared to SU/SQ in large gauge suture but only when fewer than six throws are applied to SU/SQ knots. CLINICAL RELEVANCE: The new DF knot could be an alternative for a secure ligature.

Fibro-Osseous Lesions Of The Craniofacial Complex In Horses: 30 Cases (2001-2019).

OBJECTIVE: To describe the presentation, diagnosis, treatment, and outcome for horses with fibro-osseous lesions of the craniofacial complex. STUDY DESIGN: Retrospective multicenter case series. ANIMALS: Thirty horses evaluated for fibro-osseous lesions of the skull from January 1, 2001 through December 31, 2019 in four centers. METHODS: Medical records were reviewed for signalment, clinical presentation, histological and diagnostic imaging findings, treatment instituted, and outcome. Long-term outcome information was obtained by owner questionnaire or the medical record. RESULTS: Diagnoses included ossifying fibroma in 20 of 30 horses, osteoma in eight of 30 horses, and fibrous dysplasia in two of 30 horses. Twelve of 30 lesions were diagnosed in horses <1 year old, and 20 of 30 lesions originated from the rostral mandible. The most common treatment was rostral mandibulectomy. Recurrence was not reported after complete excision. Incomplete excision was confirmed in eight horses (four ossifying fibromas, three osteomas, and one fibrous dysplasia), and follow-up information was available for seven horses. Recurrence occurred in one horse, while six horses had long-term resolution of clinical signs. Prognosis for survival and return to use was excellent in 23 horses with long-term follow-up. CONCLUSION: Fibro-osseous lesions were uncommon in this multicenter study; they were most commonly diagnosed in young animals and most frequently affected the rostral mandible. Long-term survival was excellent. CLINICAL SIGNIFICANCE: The definitive diagnosis of fibro-osseous lesions of the craniofacial complex in horses is made from results of histopathology and cannot be determined on the basis of clinical presentation alone. Surgical excision is indicated, and prognosis can be favorable even when complete surgical margins are not obtained.

En-bloc Auriculectomy for Removal of a Large Pinna-Based Ear Mass in a Horse.

A 15-year-old Pony of America (POA) gelding presented for evaluation of a large mass present on the right external pinna. Based on gross appearance, the right ear mass was suspected to be neoplastic. The most likely differential diagnosis was that of a fibroblastic sarcoid. Complete auriculectomy via use of a constricting latex-tourniquet performed under multimodal analgesia was proposed as an option to achieve complete resolution of mass growth and improve patient comfort. Benefits of latex tourniquet constriction included immediate lack of bleeding associated with amputation, gradual ischemic necrosis and sloughing of tissue distant to the site of constriction, and cost-effective application. The external pinna sloughed 3 weeks following application of the constricting latex tourniquet. Complete healing was achieved within 3 months from the time of tourniquet application. The middle ear canal sealed closed as a result of auriculectomy, with no observed long-term discomfort or morbidity aside from reduction in hearing. This is the first report of total external ear amputation in the horse. Complete auriculectomy via use of a constricting latex tourniquet is a feasible method for en-bloc removal of large, complicated ear masses.

Evaluation of phenylephrine and exercise with or without trocarization for treatment of suspected nephrosplenic entrapment in horses.

OBJECTIVE To report the outcomes of horses with suspected nephrosplenic entrapment (NSE) of the large colon treated by IV phenylephrine administration and exercise with and without trocarization (ie, medical management). DESIGN Retrospective, observational study. ANIMALS 134 horses. PROCEDURES Electronic medical records were searched to identify horses that underwent medical management for suspected NSE at a veterinary teaching hospital between 1995 and 2014. Demographic information, physical and ultrasonographic examination findings, treatment information (including the number of times the treatment was performed and patient response), surgical findings if applicable, complications, and patient outcome were recorded. Descriptive statistics were reported. RESULTS 72 horses had suspected NSE that resolved with medical treatment; 59 of 62 horses underwent laparotomy when medical management failed, and 3 were euthanized without surgery. Twenty-five of the 59 horses had confirmed NSE that was surgically corrected, and 34 had lesions other than or in addition to NSE. All horses that had surgically corrected NSE and 18 of 34 horses that had other lesions survived to hospital discharge. The odds of resolution of NSE with medical management were greater for horses that underwent ≤ 2 (vs > 2) treatments. The treatment success rate for horses that underwent trocarization was not greater than that for horses that did not have the procedure. CONCLUSIONS AND CLINICAL RELEVANCE Suspected NSE resolved with the described medical management for most horses. However, results indicated the potential for misdiagnosis was high. Timely surgical intervention is recommended for horses that fail to respond to medical treatment.

Tenotomy of the semitendinosus muscle under standing sedation versus general anesthesia: Outcomes in 20 horses with fibrotic myopathy.

OBJECTIVE: To compare outcomes after semitendinosus tenotomy performed under standing sedation versus general anesthesia. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: 20 horses with fibrotic myopathy of the semitendinosus muscle. METHODS: Medical records (2002-2015) of horses undergoing tenotomy of the semitendinosus muscle for the treatment of fibrotic myopathy were reviewed. Signalment, history, affected muscles, restrain method, surgical procedures, and short-term outcome as well as complications were retrieved from records. Long-term outcome (gait and athletic function) was assessed at least 6 months postoperatively by conversation with the owners. Pearson's χ2 statistical analysis was used to compare restrain method and affected muscles with overall outcome. Significance was set at P < .05. RESULTS: Tenotomy of the semitendinosus muscle was performed under standing sedation in 8 horses and under general anesthesia in 12 horses. Follow-up period ranged from 9 months to 10 years. Gait was improved to variable degrees in 8 of 14 horses when the semitendinosus muscle alone was affected and in 4 of 6 horses when both the semitendinosus and semimembranosus muscles were involved (P = .11). Six of 8 horses treated under standing sedation and 6 of 12 horses treated under general anesthesia exhibited some improvement in the characteristic fibrotic gait (P = .4473). Five of 6 athletic horses treated under standing sedation and 6 of 9 athletic horses treated under general anesthesia returned to their preinjury level of athleticism. Horses treated under standing sedation had no incisional complications; 2 of 12 horses treated under general anesthesia exhibited incisional drainage. CONCLUSION: Tenotomy of the semitendinosus muscle in horses with fibrotic myopathy leads to similar improvement in gait, whether performed under standing sedation or general anesthesia.

In vitro evaluation of square and surgeon's knots in large gauge suture.

OBJECTIVE: To investigate the strength and size of surgeon's and square knots for starting and ending continuous suture lines using large gauge suture. STUDY DESIGN: In vitro mechanical study. STUDY POPULATION: Knotted suture. METHODS: Surgeon's and square knots were tested using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone under linear tension on a universal testing machine. Failure mode and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated as a percentage of KHC. Comparisons were made between number of throws, suture size, suture type, and knot types. Knot volume and weight were assessed by a digital micrometer and balance, respectively. RESULTS: There were no significant differences in KHC (P = .295), RKS (P = .307), volume (P = .128), or weight (P = .310) between square and surgeon's knots at the start or end of suture lines with the same number of throws and suture type. A minimum of 6 throws were required for start knots and 7 throws at end knots to prevent unraveling. Knots tied with 3 polyglactin 910 were strongest (P < .001) and 2 polyglactin 910 produced knots with higher KHC and RKS than 2 polydioxanone (P < .001). CONCLUSION: No consistent differences were detected between knots types tied with the same suture material; however, number of throws affected KHC and RKS up to 6 throws in start or 7 throws in end knots. The configuration of square and surgeon's knots performed at the end of a continuous line alters their KHC, supporting the use of additional throws for knot security.

In Vitro Evaluation of the Size, Knot Holding Capacity, and Knot Security of the Forwarder Knot Compared to Square and Surgeon's Knots Using Large Gauge Suture.

OBJECTIVE: To investigate the strength, size, and holding capacity of the self-locking forwarder knot compared to surgeon's and square knots using large gauge suture. STUDY DESIGN: In vitro mechanical study. STUDY POPULATION: Knotted suture. METHODS: Forwarder, surgeon's, and square knots were tested on a universal testing machine under linear tension using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone. Knot holding capacity (KHC) and mode of failure were recorded and relative knot security (RKS) was calculated as a percentage of KHC. Knot volume and weight were assessed by digital micrometer and balance, respectively. ANOVA and post hoc testing were used tocompare strength between number of throws, suture, suture size, and knot type. P<.05 was considered significant. RESULTS: Forwarder knots had a higher KHC and RKS than surgeon's or square knots for all suture types and number of throws. No forwarder knots unraveled, but a proportion of square and surgeon's knots with <6 throws did unravel. Forwarder knots had a smaller volume and weight than surgeon's and square knots with equal number of throws. The forwarder knot of 4 throws using 3 USP polyglactin 910 had the highest KHC, RKS, and the smallest size and weight. CONCLUSION: Forwarder knots may be an alternative for commencing continuous patterns in large gauge suture, without sacrificing knot integrity, but further in vivo and ex vivo testing is required to assess the effects of this sliding knot on tissue perfusion before clinical application.

In Vitro Evaluation of the Aberdeen Knot for Continuous Suture Patterns with Large Gauge Suture.

OBJECTIVE: To evaluate the strength, size, and holding capacity of the Aberdeen knot compared to surgeon's and square knots using large gauge suture. STUDY DESIGN: In vitro mechanical study. STUDY POPULATION: Knotted suture. METHODS: Aberdeen, surgeon's, and square knots were tested using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone under linear tension on a universal testing machine. Mode of failure and knot holding capacity (KHC) were recorded and relative knot security (RKS) was calculated as a percentage of KHC. Knot volume and weight were quantified by a digital micrometer and balance, respectively. Strength between number of throws, suture, suture size, and knot type were compared by ANOVA and post hoc testing. P≤.05 was considered significant. RESULTS: Aberdeen knots had higher KHC and RKS than surgeon's or square knots for all suture types and number of throws (P<.001). For all suture materials, none of the Aberdeen knots unraveled, but a portion of square and surgeon's knots with <7 throws did unravel (P=.101). Aberdeen knots had a smaller volume and weight than both surgeon's and square knots with equal numbers of throws (P<.001). The knot with the combined highest RKS and smallest size and weight was an Aberdeen knot with 4 throws using 3 USP polyglactin 910. CONCLUSION: The Aberdeen knots were stronger, more secure, and smaller than surgeon's and square knots for ending a continuous suture pattern. Clinically, the Aberdeen knot may be a useful alternative for completion of continuous patterns using large gauge suture, without sacrificing knot integrity.