Resection In Dogs Research Articles

Thoracoscopic removal of cranial mediastinal masses in dogs is associated with a low conversion rate, excellent survival to discharge, and good long-term outcome.

To report the complications and outcomes associated with thoracoscopic cranial mediastinal mass resection in dogs. 49 client-owned dogs that underwent thoracoscopic cranial mediastinal mass removal. This was a retrospective cohort study (January 1, 2014, to July 31, 2023), and the medical records of 49 client-owned dogs that underwent thoracoscopic cranial mediastinal mass removal were reviewed. The signalment, history, clinicopathologic features, perioperative complications, and long-term outcome were recorded. Preoperative myasthenia gravis (MG) and megaesophagus (ME) were identified in 17 of 49 (35%) dogs and 11 of 49 (22%) dogs, respectively. The median maximal tumor diameter on CT images was 4.7 cm (range, 2.7 to 8.5 cm). Nonemergent conversion to an open procedure was necessary in 4 of 49 (8%) dogs, and dogs with conversion to an open procedure had a significantly larger median maximal CT tumor diameter than dogs without conversion (P = .03). The most common tumor type was thymoma (37/49 [76%]). The overall median survival time for dogs with thymoma was 1,102 days (95% CI, 482 to upper bound not reached). The median survival time for dogs with thymoma and concurrent presurgical MG was 182 days (95% CI, 14 to upper bound not reached). Presurgical diagnosis of MG (P = .44) or ME (P = .69) was not associated with survival time. Thoracoscopic removal of cranial mediastinal masses was associated with low conversion and complication rates. Long-term survival is possible, and thoracoscopic removal should be considered for select cases.

Narrative operative reports inconsistently record surgical information relating to resection of soft tissue sarcomas and mast cell tumors in dogs.

To report to what degree narrative operative reports for soft tissue sarcoma (STS) and mast cell tumor (MCT) resections met a predetermined template made up of essential elements. 197 consecutive client-owned animals between May 1, 2017, and August 1, 2022. A consensus list of 9 elements made up the final synoptic operative report (SR) template. Consecutive narrative surgery reports (NRs) of dogs that underwent MCT or STS resection were then reviewed to determine how many of the SR elements were present in each NR. A score was then determined for each NR out of a maximum total of 9. Overall, 197 reports (99 MCT and 98 STS) were included. The median score was 5 (56% of elements reported). No report had all 9 elements, and 1 report had none of the elements reported. When MCT and STS were analyzed independently, the median score was 6 (67% of elements reported) for MCT and 5 (56% of elements reported) for STS. There was a trend of more cases with MCT that had a preoperative diagnosis, intraoperative measurements of the tumor, and surgeon margins marked compared to dogs with STS. More dogs with STS had an estimated Enneking dose compared to dogs with MCT. Our data show that essential elements of STS and MCT resection in dogs were inconsistently recorded and no case had all elements present. This mirrors data in people and presses the need for more standardization in reporting of cancer operations in veterinary medicine.

Fascial plane mapping for superficial tumor resection in dogs. Part III: Hindlimb and pelvis.

To categorize the fascial planes and the intersections of these fascial planes in the hindlimb of the dog to facilitate preoperative planning for superficial cancers. Qualitative anatomical study. Four male and five female mixed breed dogs, weighing ~15-35 kg. Skin and subcutaneous fat were removed, and fascial planes were explored to determine borders and quality. Fascia was categorized as type I (discrete sheets), type II (adhered to thin muscles), type III (adhered to thick muscles), or type IV (associated with periosteum). Digital modification of specimen photographs was performed to map tissues. Differences in dogs were noted due to either size or sex but were sufficiently minor to allow mapping. Fasciae of the hindlimb were predominantly type II or III, with type I fascia primarily at the lateral gluteal region, fascia lata, and lateral crus. Type IV fascia was seen at the iliac wing, ischium, patella, tibial tuberosity, medial tibia, distal crus, and pes. Fascia for surgical use was thin or absent at the ischiorectal fossa, femoral triangle, extensor mechanism, medial and distal crus, and pes. Intersections and tissues at the ventral perineum may also pose challenges for maintenance of a deep margin. Fascial types and integrity of the hindlimb varied with location, with the perineum, cranial stifle, and distal limb presenting the greatest challenges. These images may be used to guide both therapeutic decision-making and intraoperative excision of superficial tumors of the hindlimb and pelvis.

Post-operative complications following apocrine gland anal sac adenocarcinoma resection in dogs.

Describe the complications associated with surgical resection of primary apocrine gland anal sac adenocarcinoma (AGASACA) tumours study design multi-institutional retrospective cross-sectional cohort study Animals Client owned dogs with spontaneous disease using the Clavien-Dindo classification system, post-operative events were assigned and described. Logistic regression analysis was used to analyse for risk factors for a significant association with complications. One hundred sixty-one dogs were included in the analysis. The post-operative sequelae, complication, and failure to cure rates specific to the anal sac site was 14%, 17% and 1%, respectively. The majority (68%) of complications were grade II or higher, therefore requiring some form of intervention. Intra-operative complications were identified in 11 cases (7%) with anorectal wall perforation being most common. An intra-operative complication was significantly associated with post-operative complications (p < 0.001; OR 7.4) while anorectal wall perforation was the only significant risk factor on regression analysis (p < 0.001; OR 19). Surgical site infection was identified in 20 of 161 (12%) of cases. Local recurrence (LR) occurred in 18% of cases at a median of 374 days (95% CI: 318-430). The only risk factor significantly associated with LR was the presence of vascular or lymphatic invasion (p=0.008; OR 3). Post-operative complications were relatively infrequent but the risk was significantly increased when there was an intraoperative complication during resection of a primary AGASACA tumour. This study provides information for the clinician regarding risk factors for post-operative complications.

Fascial plane mapping for superficial tumor resection in dogs. Part II: Forelimb.

To detail the qualitative fascial categories and fascial intersections of the forelimb of the dog to facilitate preoperative planning for superficial cancers. Qualitative anatomical study. Three male and four female mixed breed canine cadavers weighing approximately 20-35 kg. The skin and subcutaneous fat were excised. Fascial planes were incised and elevated to allow exploration of their quality and borders. Fascia was categorized as type I (discrete sheets), type II (tightly adhered to thin muscles), type III (tightly adhered to thick muscles), or type IV (associated with periosteum). Photographs of specimens were digitally modified with overlays to map tissue types. Differences between the cadavers used were largely based on muscle mass and sex, with minimal other subjective differences affecting fascial mapping. The fasciae of the forelimb were largely type II or type III, with type I fascia at the antebrachium and type IV fascia at the olecranon, scapular spine, and accessory carpal bone. Fascial integrity was often questionable or lacking distal to the distal quarter of the antebrachium. The fascial types and integrity of the forelimb varied with anatomic location with thin or absent fascia for surgical use at the elbow, carpus, and manus. This study provides information for preoperative planning and excision of superficial tumors of the forelimb. Knowledge of the potential limitations of fascia to provide a deep margin may influence selection of treatment modalities.

Fascial plane mapping for superficial tumor resection in dogs. Part I: Neck and trunk.

To provide qualitative fascial categories and classify the intersections of various fascial planes of the trunk of the dog to facilitate preoperative planning for superficial cancers. Qualitative anatomical study. Two male and three female mixed breed canine cadavers weighing approximately 15 to 35 kg. The skin and subcutaneous fat were excised. Fascial planes were incised and elevated to allow exploration of their quality and borders. Fascia was categorized as type I (discrete sheets), type II (tightly adhered to thin muscles), type III (tightly adhered to thick muscles), or type IV (associated with periosteum). Photographs of specimens were digitally modified with overlays to map tissue types. Differences between cadavers were largely associated with muscle mass or sex, with only minor anatomical differences and enough subjective similarity among specimens to allow mapping. The fasciae of the neck and trunk were predominantly type I or type II, with type III fascia at the shoulder and type IV fascia at the scapular spine, 13th rib, dorsal spinous processes, and the wing of the ilium. The superficial fasciae of the canine trunk were consistent among the dogs evaluated and can be classified as four broad fascial types. The population used was small, and individual variation should be considered when using these images in a clinical setting. The images and categorization of fascia and transitions between fascial layers detailed here provide a visual and written reference for surgeons to facilitate preoperative planning and excision of superficial cancers.

Effects of Central Venous Pressure-Guided Hemodynamic Management on Hepatic Mass Resection in Dogs

Effects of Central Venous Pressure-Guided Hemodynamic Management on Hepatic Mass Resection in Dogs

Metastasis to ipsilateral medial retropharyngeal and deep cervical lymph nodes in 22 dogs with thyroid carcinoma.

To determine the rate of nodal metastasis to the medial retropharyngeal (MRP) and deep cervical lymph nodes in dogs surgically treated for thyroid carcinoma. Retrospective study. Twenty-two client-owned dogs. Medical records between July 2015 and October 2019 at the Universities of Missouri and Florida were reviewed. Dogs that underwent thyroidectomy with concurrent elective MRP lymphadenectomy ± deep cervical lymphadenectomy were included. Tumor site, preoperative staging, and histopathological findings were recorded. Twenty-two dogs with 26 total thyroid carcinomas were included. Primary tumors were lateralized in 19 dogs, bilateral in two dogs, and bilateral and midline ectopic in one dog. All dogs underwent ipsilateral MRP resection, including bilateral resection in dogs with bilateral tumors. Three contralateral MRP lymph nodes were excised from dogs with unilateral carcinomas. Four deep cervical lymph nodes and one superficial cervical lymph node were excised. Metastases were identified in 14 lymph nodes in 10 of 22 (45%) dogs. All four excised deep cervical lymph nodes and one contralateral MRP lymph node were identified as metastatic. Size of deposit could be classified in 13 of 14 metastatic lymph nodes. Macrometastasis was detected in seven lymph nodes, micrometastasis was detected in one node, and isolated tumor cells were detected in five lymph nodes. Regional metastasis was common within the lymph nodes sampled in this population of dogs with thyroid carcinoma. These results provide evidence to justify further exploration of a larger population to verify the rate of regional metastasis and determine the prognostic impact of nodal metastasis.

Protocolo anestésico para ressecção parcial da parede torácica seguida de reconstrução em cães: relato de dois casos

O presente trabalho relata o protocolo anestésico utilizado em dois cães submetidos à cirurgia de ressecção e reconstrução da parede torácica devido a neoplasmas, no Hospital Veterinário Roque Quagliato do Centro Universitário das Faculdades Integradas de Ourinhos, São Paulo. Uma cadela poodle de 10 anos e um cão rottweiler de um ano e três meses foram submetidos à anestesia geral com isofluorano, bloqueio intercostal de, respectivamente, seis e sete espaços intercostais com lidocaína 2% e bupivacaína 0,5% e infusão contínua de morfina (0,1 mg/kg/h), lidocaína (50 μg/kg/minuto) e midazolam (0,1 mg/ kg/h). No período pós-operatório imediato, ambos receberam administração peridural de morfina 0,2 mg/kg e fentanila 2 μg/kg diluídos com NaCl 0,9% para 0,3 mL/kg. Um tubo de analgesia foi deixado durante as 48 horas subsequentes na ferida cirúrgica para administração de lidocaína e bupivacaína em total de uma dose tóxica por dia, fracionada para cinco aplicações. A prescrição analgésica pós-operatória constituiu-se de tramadol 4 mg/kg e dipirona 25 mg/kg a cada oito horas durante sete dias, juntamente com meloxicam 0,1 mg/kg a cada 24 horas durante três dias. Os animais recuperaram-se tranquilamente e não foram observados sinais de dor ao longo dos sete dias subsequentes. Recomenda-se o protocolo relatado para cirurgias de ressecção da parede torácica em cães.&#x0D;

The future for surgical margins

The future for surgical margins

A new veno-venous bypass type for ex-vivo liver resection in dogs

Ex-vivo liver resection is a procedure in which the liver is completely removed, perfused and after bench surgery, the liver is autotransplanted to the original site. Ex-vivo liver resection is an important treatment for unresectable liver tumors. This surgical procedure requires long operation time, during which blood flow must be carefully maintained to avoid venous congestion. An effective veno-venous bypass (VVB) may meet this requirement. The present study was to test our new designed VVB device which comprised one heparinized polyvinylchloride tube and three magnetic rings. The efficacy of this device was tested in five dogs. A VVB was established in 6–10 minutes. There was no leakage during the procedure. Hemodynamics was stable at anhepatic phase, which indicated that the bypass was successful. This newly-developed VVB device maintained circulation stability during ex-vivo liver resection in our dog model and thus, this VVB device significantly shortened the operation time.

Correction of rectal sacculation through lateral resection in dogs with perineal hernia - technique description

The occurrence of perineal hernias in dogs during routine clinical surgery is frequent. The coexistence of rectal diseases that go undiagnosed or are not correctly treated can cause recurrence and postoperative complications. The objective of this report is to describe a surgical technique for treatment of rectal sacculation through lateral resection in dogs with perineal hernia, whereby restoring the rectal integrity.

Use of the harmonic scalpel for soft palate resection in dogs: a series of three cases

Soft palate resection is performed to resect a redundant or diseased soft palate, often associated with brachycephalic airway obstructive syndrome (BAOS). Resection has been associated with numerous complications, including coughing, bleeding, pharyngeal oedema, respiratory obstruction and death. Traditionally, the surgery is performed by sharp dissection and suturing, but other reported techniques include the use of an electrothermal sealing device or a laser. Operative time for sharp dissection is approximately 12 min, but is shortened to around 5 min when using a laser, as the haemostatic properties of the instrument negates the need for post-resection oversewing. The successful use of a harmonic scalpel to resect redundant soft palates in three dogs is described. The resected soft palates were not oversewn and the surgical time was comparable with that for laser surgery. The first dog had a minor bleed 6 h postoperatively, possibly associated with suboptimal placement of the harmonic scalpel cutting jaws. The following two patients had no postoperative complications. The harmonic scalpel laparoscopic handpiece allowed excellent visualisation of the surgical field and rapid performance of the procedure. All three patients had markedly improved postoperative respiratory function. Cleaning and resterilisation permitted multiple reuse of the handpiece, making it cost-competitive with other surgical techniques.

Effects of denervation at ileocecal junction and ileocecal resection in dogs

To investigate neural regulation at the ileocecal junction (ICJ) and motility changes after ileocecal resection (ICR). Previous studies showed normal basal motility at the ICJ directly by force transducers in dogs, but these observations were limited to normal contractile activity. Continuous strain gauge recordings of stomach, terminal ileum, ileocecal sphincter (ICS), and colon were performed in dogs. The dogs were divided into four groups, namely control (CONT), extrinsic denervation at ICJ (ED), intrinsic denervation at ICJ (ID), and ICR groups. Colonic activity was recorded 2 h before a meal, in the early postprandial period (first 2 h), and in the late postprandial period (4-6 h after a meal). The meal lasted 5 min. Motility index was significantly increased at the ICS (P = 0.0056) and proximal colon (P = 0.0059) after feeding. However, such changes were not observed in the ED and ID groups. The amplitude of contractions at proximal colon in the interdigestive state was significantly decreased by ED. In the ID and ICR groups, the numbers of nonmigrating contractions were significantly decreased (P < 0.05), and colonic migrating motor complex (CMMC) ratio was significantly higher than that of the CONT group (P < 0.001). The dogs in these two groups had diarrhea. Gastrocolonic response at the ICJ may require both intrinsic and extrinsic innervation. When ID was performed, CMMC ratio increased. As a result, intraluminal water absorption may have decreased. ID may be one of the causes of diarrhea after ICR.

Comparison of Two Suturing Techniques in Tracheobronchial Anastomosis Following the Wedge Carinal Resection in Dogs

Summary Tracheobronchial resection in humans is a still problem in lung cancer invading the carina, because there is not a standard surgical procedure. This study aimed to compare postoperative complications and histopathological results of simple continuous and simple interrupted suturing techniques in tracheobronchial anastomosis following the wedge carinal resection in dogs. Twelve mongrel dogs were divided into A and B groups. Right pneumonectomy with wedge carinal resection technique was performed under general anesthesia, and then tracheobronchial resection line was sutured simple continuously in group A and simple interruptedly in group B. The dogs were checked during two months in terms of postoperative complications, and euthanized at the end of two months to evaluate tracheobronchial anastomosis lines histopathologically. No postoperative complication was encountered in group A; but, 2 dogs in group B died due to respiratory failure on postoperative 4 th and 12 th days. Autopsy of the dogs revealed tracheobronchial dehiscence and opening of the simple interrupted suturing line, which was considered operative technique failure of suturing. Histopathologically, the sections taken from tracheobronchial anastomosis line had similar microscopic results in both group. Statistically, Fisher’s exact test was applied between groups to determine the diff erences with regard to postoperative complications and histopathological results. There was no statistically significant diff erences between the groups in postoperative complications and histopathological results. In conclusion, operative technique failure of suturing is still common in tracheobronchial anastomosis; however, taking the histopathological results of the study into consideration, it has been implied that both suturing technique can be performed in tracheobronchial anastomosis following the wedge carinal resection.

Evaluation of anastomotic microcirculation after low anterior rectal resection: an experimental study with different reconstruction forms in dogs

Data on anastomotic microcirculation of coloanal anastomoses are contradictory. Therefore, it was the aim of the present study to investigate perianastomotic blood perfusion in a standardized experimental setting comparing three forms of reconstruction using laser fluorescence videography, a new method for the evaluation of microcirculation. After a standardised rectal resection in dogs, reconstruction was performed as straight end-to-end (n = 6), side-to-end (n = 6), or J-pouch (n = 6) coloanal anastomosis. Bowel perfusion was evaluated using IC-View laser fluorescence videography. The perfusion index was significantly reduced in all three groups compared to the reference regions: endto-end anastomosis, median, 93% (range, 63%-136%); side-to-end-anastomosis, 65% (35%-138%); colonic-J-pouch anal anastomosis, 52% (32%-72%); p < 0.001). Straight coloanal anastomoses provide better anastomotic microcirculation after rectal resections than colonic-J-pouch anal anastomoses or side-to-end anastomoses. However this effect does not seem to be decisive for the prevention of anastomotic leaks.

Extensive small bowel resection in dogs and cats: 20 cases (1998–2004)

To determine outcome in dogs and cats that underwent extensive (ie, > 50%) resection of the small intestine and identify factors associated with outcome. Retrospective case series. 13 dogs and 7 cats. Medical records were reviewed, and follow-up information was obtained. In all 7 cats and in 8 of the 13 dogs, extensive intestinal resection was performed because of a foreign body. Mean+/-SD estimated percentage of intestine that was removed was 68+/-14% (range, 50% to 90%). Two dogs were euthanized 3 days after surgery because of dehiscence of the surgical site and development of septic peritonitis; 1 dog died of acute respiratory distress syndrome 5 days after surgery. The remaining 10 dogs and 7 cats were discharged from the hospital, and follow-up information was available for 15 of the 17. Median survival time was 828 days, and 12 of the 15 animals for which long-term follow-up information was available had good outcomes. However, none of the factors examined, including percentage of intestine resected, were significantly associated with outcome. Most dogs and cats that underwent extensive resection of the small intestine had a good outcome. The amount of intestine resected was not associated with outcome. These data may be useful in providing prognostic information in cases of extensive small intestinal resection.

Effect of mechanical bowel preparation on anastomotic integrity following low anterior resection in dogs.

To assess the effect of mechanical bowel preparation on anastomotic integrity after low anterior resection, 36 mongrel dogs were randomized to have low anterior resection with or without mechanical bowel preparation. All dogs received prophylactic antibiotics and anastomotic integrity was assessed on the ninth postoperative day by barium enema, inspection of anastomoses for defects after careful excision at laparotomy, and anastomotic bursting pressures. Bursting pressures were significantly higher (P less than 0.005) in the group with bowel preparation. Anastomotic defects were present in 13 per cent of animals with bowel preparation and 47 per cent without bowel preparation (P = 0.057). Pelvic abscess and death from peritonitis occurred in 6 per cent of the group with bowel preparation and 29 per cent of the unprepared group. Mechanical bowel preparation significantly enhanced anastomotic integrity and reduced complications in this model.

Glutamine-enhanced enteral diet improves nitrogen balance without increasing portal ammonia

Following surgical stress the jejunum actively metabolizes endogenous glutamine, a non-essential amino acid, to produce alanine and ammonia, which augments substrate flow to the liver at a time when oral intake of nutrients is decreased. Oral glutamine supplementation theoretically may modify the response to injury. This study was designed to demonstrate the role of the jejunum in postinjury glutamine metabolism and to evaluate the influence of enteral glutamine supplements on nitrogen and ammonia metabolism after laparotomy and bowel resection in dogs. Oral glutamine in the presence of an intact small bowel significantly improved nitrogen balance (461 mg kg body-weight-1 day-1) compared with a control diet (-370 mg kg-1 day-1) (P less than 0.05, analysis of variance). Removal of the proximal small bowel prevented this beneficial effect of glutamine (-507 mg kg-1 day-1). Glutamine-supplemented and control diets were associated with similar portal ammonia concentrations throughout the study.

Experimental study of extracorporeal lung resection in dogs: ex situ sleeve resection and autotransplantation of the pulmonary lobe after extended pneumonectomy for central lung cancer

Objective Extracorporeal lung resection as an alternative to pneumonectomy for central lung cancer is a procedure in which the unilateral lung is extirpated, removing the pulmonary lobe with the cancers and replanting the residual pulmonary lobe. The aim of this study was to investigate whether extracorporeal lung resection for lung cancer can be performed safely. Methods Nineteen dogs were divided into the control and extracorporeal lung resection groups. The former (n = 5) underwent lung autotransplantion, and the latter was subdivided into ND1 (n = 7) and ND2 (n = 7) groups on the basis of the manner of lymph node dissection. By comparing the 3 groups, the adverse effects of lymph node dissection were examined. Results All dogs in the control group had no complications. Four dogs in the ND1 group survived for 90 to 630 days after the operation. In the ND2 group 5 dogs succumbed within 30 days after the operation, although the other 2 dogs survived for 391 and 573 days, respectively. Bronchopulmonary fistulas were seen in 1 of the ND1 dogs and 3 of the ND2 dogs. Two of the latter were free of thrombus formation in the pulmonary arteries and veins of the autografts. In the ND2 group, compared with the control and ND1 group, the tissue blood flow at the bronchial anastomotic site indicated reduction between the 3rd and 14th postoperative days. Conclusion The extensive lymph node dissection had severe adverse effects on bronchial anastomotic healing in extracorporeal lung resection. Therefore extracorporeal lung resection can be applied to only a very limited number of patients with N0 or N1 disease.