Biomechanical comparison of bone staple fixation methods with suture material for median sternotomy closure using 3D-printed bone models.

AIM: To compare the biomechanical properties of three different sternal closure techniques in a 3D-printed bone model of a sternum from a 30-kg dog. METHODS: Median sternotomy was performed on a total of 90 three-dimensional (3D) copies of a polycarbonate (PC) model of a sternum, generated from the CT images of the sternum of a 30-kg German Shepherd dog. Three different methods were used to repair the sternotomies: polydioxanone suture (group PDS, n = 30), stainless steel bone staples (group SS, n = 30), and nitinol bone staples (group NS, n = 30). Each repair method was tested by applying tensile force in one of three ways (longitudinally, laterally, or torsionally) resulting in a sample size of n = 10 for each repair method-loading combination. In all experiments, the loads at 1-mm and 2-mm gap formation, failure, and the displacement at the failure point were measured. RESULTS: In lateral distraction and longitudinal shear tests, NS and SS staple repairs required application of significantly greater force than PDS across all displacement criteria (1 and 2 mm). NS exhibited significantly greater failure load than PDS. In torsion tests, NS required significantly greater application of force compared to SS or PDS at all displacement criteria (1 and 2 mm) and exhibited a greater failure load than PDS. In terms of displacement at failure point, PDS suture showed more displacement than SS or NS across all experiments (laterally, longitudinally, torsionally). CONCLUSIONS: In this study, bone staples were mechanically superior to PDS suture in median sternotomy closure using 3D-printed bone model in terms of 1-mm, 2-mm displacement loads, and displacement at failure. NS had a higher failure load than PDS under lateral, longitudinal, and torsional distraction. CLINICAL RELEVANCE: These study results imply that bone staples can be considered as an alternative surgical method for median sternotomy closure in dogs.

Outcomes following combined median sternotomy and ventral midline laparotomy for bicavitary penetrating wooden foreign bodies.

Combined abdominal and thoracic pathology caused by extra-gastrointestinal migration of an ingested wooden foreign body (WFB) is an uncommon but serious injury. Presenting clinical signs are typically nonspecific and, in the absence of observed WFB ingestion, diagnosis is challenging. Treatment requires concurrent abdominal and thoracic surgical exploration to remove the WFB and address injuries caused by its migration. This case series describes perioperative characteristics and outcomes in 4 dogs following combined median sternotomy and ventral midline laparotomy (CMSVML) for bicavitary penetrating WFBs. Key clinical message: Treatment of bicavitary penetrating WFBs with CMSVML provided postoperative outcomes similar to those in previous reports; however, high-grade complications and prolonged hospitalization were commonly encountered.

Résultats après sternotomie médiane et laparotomie médiane ventrale combinées pour des corps étrangers en bois pénétrant bicavitaires. La pathologie combinée abdominale et thoracique causée par la migration extra-gastro-intestinale d'un corps étranger en bois (WFB) ingéré est une blessure rare mais grave. Les signes cliniques présentés sont généralement non spécifiques et, en l'absence d'ingestion observée de WFB, le diagnostic est difficile. Le traitement nécessite une exploration chirurgicale abdominale et thoracique simultanée pour retirer le WFB et traiter les blessures causées par sa migration. Cette série de cas décrit les caractéristiques peropératoires et les résultats chez 4 chiens après une sternotomie médiane et une laparotomie médiane ventrale combinées (CMSVML) pour des WFB pénétrantes bicavitaires.Message clinique clé:Le traitement des WFB pénétrants bicavitaires avec CMSVML a fourni des résultats postopératoires similaires à ceux des rapports précédents; cependant, des complications de haut grade et une hospitalisation prolongée ont été fréquemment rencontrées.(Traduit par Dr Serge Messier).

Biomechanical comparison of canine median sternotomy closure using suture tape and orthopedic wire cerclage.

OBJECTIVE: To compare the mechanical properties of suture tape and orthopedic wire cerclage in an ex vivo canine median sternotomy model. STUDY DESIGN: Ex vivo. ANIMALS: Twelve large-breed canine cadaveric sternums. METHODS: Median sternotomies were performed, leaving the manubrium intact. The specimens were randomly assigned to group W (20-gauge stainless steel orthopedic wire cerclage in a figure-of-eight pattern) or group ST (suture tape in a figure-of-eight pattern). Each specimen was laterally distracted until failure using an electrodynamic materials-testing system. RESULTS: No differences were observed for displacement, yield load, maximum load, implant failure between the groups. The orthopedic wire construct was stiffer than the suture tape construct. CONCLUSION: Suture tape was biomechanically similar to orthopedic wire cerclage for sternotomy closure in dogs, although wire constructs were stiffer. CLINICAL SIGNIFICANCE: Suture tape may represent an alternative to cerclage wire for sternotomy closure in dogs. Additional studies evaluating its clinical use are needed.

Porcupine quilling-associated pneumothorax in dogs: 25 cases (2001-2022).

OBJECTIVE: To describe the clinical outcome of dogs that developed pneumothorax after an encounter with a porcupine. ANIMALS: 25 client-owned dogs from 2 practices in New England. PROCEDURES: The medical records were searched for those of dogs that underwent care for porcupine quilling-associated pneumothorax (PQAP) between August 1, 2001, and October 15, 2023. Dogs were all large-breed dogs or large mixed-breed dogs and most frequently had clinical signs associated with pneumothorax, including labored breathing and tachypnea. RESULTS: No cases occurred in winter months. Diagnostic imaging was useful for identifying pneumothorax, but not for localizing quills. Twenty-one of the 25 dogs underwent median sternotomy for quill removal, with quills found in lung tissue of 19 dogs. Two dogs had no intrathoracic quills identified at thoracotomy, but residual quills were identified in the intercostal muscles. Four dogs were discharged without surgery after apparent resolution of the pneumothorax. All dogs survived to hospital discharge; however, 5 dogs required subsequent quill removal from ongoing quill migration. CLINICAL RELEVANCE: Porcupine quillings may result in traumatic pneumothorax associated with quill migration. Following quill removal, monitoring for the development of a pneumothorax is advised. Surgical removal of quills from the lungs has a good prognosis.

Ultrasound-guided bilateral erector spinae plane block in dogs undergoing sternotomies anaesthetised with propofol-dexmedetomidine continuous infusion.

BACKGROUND: To describe the use of a bilateral thoracic (T5 - T9) ultrasound-guided erector spinae plane block (UG-ESPB) in dogs undergoing sternotomy anaesthetised with propofol and dexmedetomidine continuous infusions. METHODS: Demographic information, perioperative anaesthetic and analgesic drugs, the prevalence of hypotension and nociceptive events, and their treatment, were recorded and analysed. Local anaesthetic injection point, volume and concentration were reported for each dog. In attempt to differentiate somatic nociception from visceral nociception, the surgery was divided into three timeframes: from the skin incision to the thoracic cavity opening; from the latter to the beginning of its closure; from thoracic cavity closure to the end of surgery. RESULTS: Overall, 10 dogs were included and four experienced nociception: somatic nociception was recorded in one dog, whereas visceral nociception was recorded in four dogs. The overall fentanyl consumption to control nociception was 0.3 µg/kg/h. No adverse events associated with the UG-ESPB were reported. CONCLUSION: The bilateral UG-ESPB could be used as a part of a multimodal analgesic technique in dogs undergoing sternotomies. However, more clinical studies are warranted to assess its safety and effects.

Comparison of median sternotomy closure-related complication rates using orthopedic wire or suture in dogs: A multi-institutional observational treatment effect analysis.

OBJECTIVE: To determine and compare median sternotomy (MS) closure-related complication rates using orthopedic wire or suture in dogs. STUDY DESIGN: Multi-institutional, retrospective observational study with treatment effect analysis. ANIMALS: 331 client-owned dogs, of which 68 were excluded. METHODS: Medical records of dogs with MS were examined across nine referral centers (2004-2020). Signalment, weight, clinical presentation, surgical details, complications, and outcomes were recorded. Follow-up was performed using patient records and email/telephone contact. Descriptive statistics, treatment effect analysis and logistic regression were performed. RESULTS: Median sternotomy closure was performed with wire in 115 dogs and suture in 148. Thirty-seven dogs experienced closure-related complications (14.1%), 20 in the wire group and 17 in the suture group. Twenty-three were listed as mild, four as moderate and 10 as severe. Treatment effect analysis showed a mean of 2.3% reduction in closure-related complications associated with using suture versus wire (95% CI: -9.1% to +4.5%). In multivariable logistic regression, the only factor associated with increased risk of closure-related complications was dog size (p = .01). This effect was not modified by the type of closure used (interaction term: OR = 0.99 [95% CI: 0.96/1.01]). CONCLUSION: The incidence of closure-related complication after MS was low compared to previous reports. The likelihood of developing a closure-related complication was equivalent between sutures and wires, independent of dog size, despite a higher proportion of complications seen in larger dogs (≥20 kg). CLINICAL SIGNIFICANCE: Use of either orthopedic wire or suture appear to be an appropriate closure method for sternotomy in dogs of any size.

Closure-related complications after median sternotomy in cats: 26 cases (2010-2020).

OBJECTIVES: The aim of this study was to determine closure-related complications and outcome after median sternotomy (MS) in cats. METHODS: This was a retrospective, multicentric study. The medical records of cats undergoing MS from six referral hospitals were reviewed (2010-2020). Data retrieved included signalment, history, presenting complaints, surgery, patient outcomes and complications. Follow-up was performed via patient records and email/telephone contact with both owners and referring veterinarians. Descriptive statistics were performed. RESULTS: Data on 36 cats were collected; four were excluded due to insufficient follow-up and six died less than 5 days after surgery. Twenty-six cats survived to discharge (survival rate 81%). Three cats had a full sternotomy (FS) performed and 23 cats a partial sternotomy (PS). Of the cats that underwent a PS, six included the manubrium (PSM) and three included the xyphoid process. For 14 cats, the length of sternotomy was unknown. Sternotomy closure was performed with suture in all cats. Two cats (7.7%) developed closure-related complications, both after PSM, during the long-term follow-up, one mild, slightly displaced sternal fracture and one severe, sternal dehiscence (without skin wound dehiscence) requiring revision surgery. No seroma, surgical site infection or wound dehiscence occurred. The most common reason for MS was the presence of a thoracic mass (17/26; 65%), with thymoma being the most common (11/17; 65%). CONCLUSIONS AND RELEVANCE: MS has a low closure-related complication risk in cats when compared with dogs. Complications in cats present differently to what has been previously described in dogs.

Crimped monofilament nylon leader for median sternotomy closure in 10 dogs.

OBJECTIVE: To describe and report the outcomes after closure of median sternotomies with crimped monofilament nylon leader (MNL) in dogs. STUDY DESIGN: Retrospective observational study. ANIMALS: Dogs (n = 10) that underwent intrathoracic surgery through a median sternotomy approach. METHODS: The median sternotomy was closed in a peristernal figure eight pattern with crimped MNL. Medical records were reviewed for clinical and histopathological findings and complications. Owners or veterinarians were contacted to collect long-term follow-up information. RESULTS: The technique was simple, with no intraoperative complications. Postoperative infection was documented in one dog, requiring removal of a single MNL and associated crimp clamp. Delayed healing of the surgical incision in one dog was managed conservatively. No other complications were documented throughout long-term follow-up at a median of 488 days (range, 199-608). CONCLUSION: Median sternotomies were successfully closed with crimped MNL and were associated with a low complication rate. CLINICAL SIGNIFICANCE: Crimped MNL represents an alternative method to close median sternotomies in dogs.

Sternotomy and ventral slot decompression for treatment of T1-2 intervertebral disk disease in a Dachshund.

CASE DESCRIPTION A 9-year-old 7.5-kg (16.5-lb) castrated male Dachshund was referred for emergency evaluation of pelvic limb paraplegia of < 24 hours' duration. CLINICAL FINDINGS A spinal cord lesion between T3 and L3 was suspected given the dog's history and neurologic examination results. Computed tomography and myelography spanning T3 through L4 identified an extradural compressive lesion at the L3-4 disk space. Hemilaminectomy was performed, and disk material adhered to and compressing the spinal cord was identified. However, because the material appeared to have been present for an extended period, postoperative CT of the cervicothoracic region was performed, which revealed extrusion of disk material from the T1-2 space and marked spinal cord compression. TREATMENT AND OUTCOME A sternotomy of the manubrium and ventral slot decompression of the T1-2 disk space were performed successfully without entering the thoracic cavity. A large amount of disk material was removed from the spinal canal. No loss of intrathoracic negative pressure was appreciated, and intraoperative complications included only mild hemorrhage. The dog maintained pelvic limb pain sensation postoperatively and regained motor function 2 days after surgery. CLINICAL RELEVANCE Intervertebral disk disease is rare at T1-2 in Dachshunds. Typically, a dorsal approach has been used to decompress the spinal cord, but findings for this dog suggested that a ventral approach may also be appropriate. Consideration should be given to include the T1-2 disk space when performing advanced imaging in dogs because of the inconsistent ability to identify lesions at this location by means of neurologic examination.

Median sternotomy versus intercostal thoracotomy for lung lobectomy: A comparison of short-term outcome in 134 dogs.

OBJECTIVE: To compare short-term outcomes between dogs undergoing lung lobectomy via median sternotomy (MS) or intercostal thoracotomy (ICT). STUDY DESIGN: Retrospective case control study. METHODS: Medical records of dogs that underwent lung lobectomy via MS or ICT at a single institution were reviewed for demographics, intraoperative findings, and postoperative management and outcomes. Dogs with pleural effusion, pneumonia, migrating foreign body, lung abscess, spontaneous pneumothorax, or lung lobe torsion were excluded. Short-term outcome factors up were compared up to the time of death, euthanasia, or discharge from the hospital. RESULTS: One hundred and thirty-four dogs met the inclusion criteria. Forty-one (31%) dogs underwent MS and 93 dogs (69%) underwent ICT. Fluid production from the chest tube (P = .0061), alveolar arterial pressure gradient (P = .0001), and complications requiring intervention (P = .0245) were more common in the MS group than the ICT group. Pain management and all other short-term outcome factors did not differ between procedures. Five dogs from the MS group and 4 from the ICT group were euthanized in the postoperative period (P = .0925). CONCLUSION: In a surgical procedure that does not preclude either approach, ICT may be more desirable than MS in terms of postoperative pain, oxygenation, and complications. However, since no other short-term measure of outcome differed, we can state that both MS and ICT are well tolerated by dogs.

Retrospective comparison of costs between medical and surgical treatment of canine pyothorax.

This study compared costs of treating dogs with pyothorax medically versus surgically. Medical records from the University of Wisconsin School of Veterinary Medicine were searched for cases of pyothorax that underwent either medical or surgical treatment. Patients undergoing surgery were subdivided into early (ES; < 48 h) and late (LS; > 48 h) surgery groups. Costs and length of stay were compared between treatment groups. Treatment costs were adjusted for inflation. Nineteen dogs were included in analysis; 7 in the medical group (MG), 5 in the ES group, and 7 in the LS group. Total costs were significantly lower in the MG than in the LS group. Total costs were less for the MG than the ES group, and for ES than LS, but the differences did not achieve significance. Preoperative costs were higher in the LS than the ES group. We conclude that surgery for canine pyothorax is less costly if pursued earlier than later.

Comparaison rétrospective des coûts entre le traitement médical et chirurgical d'un pyothorax canin. Cette étude a comparé les coûts de traiter les chiens souffrant d'un pyothorax par voie médicale par opposition à une voie chirurgicale. Une recherche a été effectuée dans les dossiers médicaux du College of Veterinary Medicine, University of Wisconsin pour trouver des cas de pyothorax où les animaux avaient subi soit un traitement médical ou chirurgical. Les patients subissant une chirurgie ont été subdivisés en des groupes de chirurgie précoce (ES; < 48 h) et tardive (LS; > 48 h). Les coûts et la durée du séjour ont été comparés entre les groupes de traitement. Les coûts de traitement ont été ajustés pour l'inflation. Dix-neuf chiens étaient inclus dans l'analyse; sept dans le groupe médical (MG), cinq dans le groupe ES et sept dans le groupe LS. Les coûts totaux étaient significativement inférieurs dans le MG par rapport au groupe LS. Les coûts totaux étaient inférieurs pour le groupe MG par rapport au groupe ES et pour le groupe ES par rapport au groupe LS, mais les différences n'étaient pas significatives. Les coûts préopératoires étaient supérieurs dans le groupe LS par rapport au groupe ES. Nous tirons la conclusion que le coût de la chirurgie pour le pyothorax canin est inférieur si la chirurgie est réalisée tôt.(Traduit par Isabelle Vallières).

Mechanical comparison of monofilament nylon leader and orthopaedic wire for median sternotomy closure.

OBJECTIVES: To compare the mechanical properties of monofilament nylon leader and orthopaedic wire for median sternotomy closure in the dog. MATERIALS AND METHODS: Median sternotomy was performed in 14 canine cadaver sternums with the manubrium intact. The sternotomy was closed with either 80 lb monofilament nylon leader or 20G orthopaedic stainless steel wire in a peristernal figure of 8 pattern. Constructs were loaded in a servohydraulic material testing machine. Load at yield, maximum load, stiffness, displacement and mode of failure were compared between constructs subjected to a single cycle load to failure. RESULTS: No significant differences were found in load at yield, maximum load, stiffness or displacement between the monofilament nylon leader and the stainless steel wire constructs. No implant failure was evident in the stainless steel wire constructs. Four of the monofilament nylon leader constructs failed by pulling of the nylon through the crimp. CLINICAL SIGNIFICANCE: Monofilament nylon leader is mechanically comparable to stainless steel wire and potentially a suitable alternative for closure of median sternotomy in the dog.

Mechanical comparison of median sternotomy closure in dogs using polydioxanone and wire sutures.

OBJECTIVES: To compare the mechanical properties of two different materials for canine median sternotomy closure. STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Twelve canine cadaveric entire sternum and portion of associated ribs and musculature. METHODS: Median sternotomy leaving the manubrium intact was closed using polydioxanone and stainless steel wire in a figure of eight pattern. Constructs were loaded in a servohydraulic material testing system and displacement was compared at loads of 125, 150, 200, 250, 300, 350 and 400 N, and at failure. RESULTS: Displacement at loads up to 400 N and failure did not show any statistical difference between the polydioxanone and the stainless steel wire. However, the loading forces to create failure of the construct were superior for the stainless steel. Polydioxanone and stainless steel wire had the same response to distractive forces for loads applied up to 400 N. CLINICAL SIGNIFICANCE: This study cannot recommend the use of polydioxanone over wires but suggests that polydioxanone can potentially be an alternative for primary median sternotomy closure in selected patients.

Median sternotomy and ventral stabilisation using pins and polymethylmethacrylate for a comminuted T5 vertebral fracture in a Miniature Schnauzer.

A 2.9 kg Miniature Schnauzer was referred to our clinic, the Emergency & Critical Care Medicine Service at the Michigan State University Veterinary Teaching Hospital, following a dog fight. Physical examination findings upon admission included multiple thoracic wounds, absence of hindlimb deep pain, and marked Schiff-Sherrington syndrome. Computed tomography imaging revealed thoracic wall penetration and a comminuted T5 vertebral fracture. Thoracic exploration and thoracic wall repair were performed through a median sternotomy. The vertebral fracture was exposed and stabilised intra-thoracically through the same approach using pins and polymethylmethacrylate. The pins were placed percutaneously into the vertebral bodies of the adjacent vertebrae. Recovery was uncomplicated and fracture healing was documented eight weeks postoperatively. Spinal trauma secondary to dog fights is relatively common. The presence of concurrent penetrating thoracic injury negatively affects prognosis and necessitates thoracic exploration as soon as feasible. The approach should allow complete thoracic exploration to repair parietal and visceral damage, thus indicating the need for median sternotomy rather than an intercostal approach. The present case report suggested that median sternotomy can be used to safely apply stabilisation devices for the treatment of concurrent spinal trauma. Direct visualisation of the vertebral bodies permitted optimal implant anchorage as compared to potentially more hazardous techniques such as dorsal pinning.