Performance time and leak pressure of hand-sewn and skin staple intestinal anastomoses and enterotomies in cadaveric cats

OBJECTIVE

To compare time to construct completion and leak testing between hand-sewn and skin staple anastomoses and enterotomies in cats.

STUDY DESIGN

Ex vivo, randomized study.

ANIMALS

Fresh feline cadavers (n = 20).

METHODS

Jejunal segments (8 cm) were harvested and tested on the same day as euthanasia. From each cadaver, one segment was randomly assigned to control (C), hand-sewn enterotomy (HSE), and skin staple enterotomy (SSE) groups, and two segments were randomly assigned to hand-sewn anastomosis (HSA) and skin staple anastomosis (SSA) groups. Construct completion time, initial leak pressure (ILP), and maximum intraluminal pressure were compared. Leakage location was reported.

RESULTS

Mean time (s) ± SD was longer (p < .001) for HSA (317.0 ± 50.9) than SSA (160.8 ± 13.1) and for HSE (172.0 ± 36.5) than SSE (20.3 ± 5.0). ILP (mean ± SD) for C (600.0 mmHg ±0.0) was higher (p < .001) than all constructs. ILP (mean ± SD) for SSA (124.2 mmHg ±83.7) was not different (p = .49) than HSA (86.1 ± 51.9), but HSE (200.3 ± 114.7) was higher (p < .001) than SSE (32.2 ± 39.7). Immediate leakage from the center of enterotomy closure was observed in 7/20 SSE.

CONCLUSIONS

HSA construct completion took twice as long as SSA with no difference in intraluminal pressures. Although HSE construct completion took 8x as long as SSE, HSE had higher intraluminal pressures.

CLINICAL SIGNIFICANCE

In cats, SSA may be an alternative to HSA for intestinal anastomosis, but SSE is not recommended as an alternative to HSE for intestinal enterotomy closure.

Use of real-time near-infrared fluorescence to assess gastric viability in dogs with gastric dilatation volvulus: A case-control study

OBJECTIVE

To describe near-infrared fluorescence (NIRF) for assessment of gastric viability and describe NIRF's influence on the surgeon's operative strategy in dogs with gastric dilatation and volvulus (GDV).

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Twenty dogs with GDV and 20 systemically healthy dogs.

METHODS

Following gastric derotation, the surgeon's subjective assessment of gastric viability was recorded prior to near-infrared imaging. Changes in the surgeon's initial assessment of viability based on the visual pattern of gastric fluorescence was recorded. If nonviable (lack of defined vessels), a partial gastrectomy was performed and submitted for histopathology. The stapled gastrectomy line was imaged. Viable (defined vessels) and nonviable fluorescence intensities were compared with healthy dogs undergoing surgery for nongastrointestinal disease.

RESULTS

Subjective assessment diagnosed 17 viable and three nonviable GDVs (2 fundi; 1 cardia). Near-infrared imaging demonstrated nonviable gastric fluorescence in 4 dogs (3 fundi/cardia; 1 fundus). The surgeon's margins for resection were altered in 3/20 dogs. Fluorescence intensity (cardia, fundus, body, pylorus) was lower in GDV viable (30.59%, p = .04; 38.17%, p < .01; 51.18%, p < .01; 44.12%, p= .01) and nonviable (11.00%, p < .01; 4.33%, p < .01; 57.67%, p = .22; 54.33%, p = .72) dogs compared to healthy controls (44.7%, 70.05%, 84.00%, 63.95%). Fundic fluorescence was less in nonviable gastric tissue in comparison with viable gastric tissue (p = .03). Fluorescence of the gastrectomy staple line approximated that of viable tissue.

CONCLUSION

Near-infrared fluorescence can identify histologically confirmed nonviable gastric tissue.

CLINICAL SIGNIFICANCE

These results provide enough evidence to support the implementation of NIRF as an adjunct to gross examination of the gastric wall in dogs with GDV.

Gastrointestinal thickness, duration, and leak pressure of five intestinal anastomosis techniques in cats

OBJECTIVE

To compare time to construct completion and resistance to leakage for five intestinal anastomosis techniques in cats and to report normal feline gastrointestinal thickness.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Grossly normal intestinal segments (n = 120) from 10 fresh cat cadavers.

METHODS

A total of 8 cm segments of fresh feline cadaveric intestine were collected, and mural thickness was recorded. Segments were randomly allocated between a control group (n = 20 segments) and five treatment groups (20 segments/group with 2 segments/construct = 10 constructs per group): (1) hand-sewn anastomosis - simple interrupted (HSA-SI), (2) hand-sewn anastomosis - simple continuous (HSA-SC), (3) functional end-to-end stapled anastomosis (FEESA), (4) functional end-to-end stapled anastomosis with oversew (FEESA-O), (5) skin stapled anastomosis (SS). Time to construct completion, leakage location, initial leak pressure (ILP), and maximum intraluminal pressure (MIP) were compared.

RESULTS

Mean mural thickness ± SD (mm) for the stomach, duodenum, jejunum, and ileum were 1.66 ± 0.28, 2.05 ± 0.18, 2.28 ± 0.30, and 2.11 ± 0.39, respectively. ILPs (mean ± SD) for HSA-SI (165 ± 122 mmHg), HSA-SC (149 ± 83), FEESA-O (63 ± 25, FEESA (84 ± 59), SS (77 ± 56), and control segments (>500) were compared. There was no statistically significant difference in ILP (p > .08) or MIP (p > .084) between any treatment groups. Nonoversewn FEESAs were 2.4 times faster to perform compared to oversewn FEESA and SS groups, and 4.7 times faster than HSA (p < .001).

CONCLUSION

All anastomosis techniques provide resistance to leakage that is supraphysiological to that of the normal maximum intraluminal pressure. HSA take longer to complete than stapled anastomoses.

CLINICAL SIGNIFICANCE

All anastomotic techniques may be appropriate in cats. Hand-sewn anastomoses result in a longer surgical time.

Complications and outcome following staphylectomy and folded flap palatoplasty in dogs with brachycephalic obstructive airway syndrome

OBJECTIVE

To compare the prevalence of pre-, intra-, and postoperative variables and complications associated with staphylectomy (S) and folded flap palatoplasty (FFP).

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Client-owned dogs (n = 124).

METHODS

Medical records of S and FFP dogs from a veterinary teaching hospital were reviewed between July 2012 and December 2019. Signalment, clinical pre-, intra-, and postoperative data were collected and reviewed. Median (interquartile range) was reported.

RESULTS

A total of 124 dogs among 14 breeds underwent surgical treatment for an elongated soft palate with either a S (n = 64) or FFP (60). FFP dogs without concurrent non-airway procedures were associated with longer duration of surgery (p = .02; n = 63; S, median = 51 min [34-85]; FFP, median = 75 min [56.25-94.5]) and anesthesia (p = .02; n = 63; S, median = 80 min [66-125]; FFP, median = 111 min [91-140.8]). Neither soft palate surgery was associated with the occurrence of anesthetic complications (p = .30; 99/120; S, 49; FFP, 50), postoperative regurgitation (p = .18; 27/124; S, 17; FFP, 10), or with hospitalization duration (p = .94; n = 124; S, median = 1 day [1]; FFP, median = 1 [1]). Postoperative aspiration pneumonia (9/124; S, 4; FFP, 5) and major complications were rare (5/124; S, 3; FFP, 2).

CONCLUSION

S and FFP had similar anesthetic and perioperative complications, although FFP dogs had longer anesthetic and operative times.

CLINICAL SIGNIFICANCE

Although FFP took longer, no other clinically significant differences were appreciated between S and FFP procedures. Because of limitations inherent in study design, surgeons should continue to use clinical judgment when deciding on a procedure.

Geometric, landmark-guided technique reduces tissue trauma, surgery time, and subjective difficulty for canine peripheral lymphadenectomies: an educational crossover study

OBJECTIVE

To compare the effect of a geometric, landmark-guided lymphadenectomy (LL) approach to peripheral lymph nodes (LNs) on successful LN identification, surgical time, tissue trauma, and ease of LN identification compared to standard lymphadenectomy (SL) and methylene blue-guided lymphadenectomy (MBL).

SAMPLE

18 adult, mixed-breed canine cadavers operated on by 7 veterinarians and 5 fourth-year veterinary students between July 23 and October 12, 2022.

METHODS

Participants were provided standardized, publicly available materials regarding the anatomy and surgical techniques for SL of 3 peripheral lymphocentrums: superficial cervical, axillary (ALN), and superficial inguinal (SILN). Participants performed the 3 SLs unilaterally on canine cadavers. Thereafter, they were randomly assigned to 2 crossover groups: MBL and LL. All dissections were separated by at least 2 weeks for each participant. Primary outcome measures included successful LN identification, surgical time, tissue trauma scores, and subjective difficulty.

RESULTS

Successful LN identification was highest with LL (86%) compared to SL (69%) and MBL (67%). Subjective difficulty scores were reduced with LL for SILN dissections. Tissue trauma scores were reduced when using LL for ALN and SILN compared to MBL and SL. Time to LN identification was reduced for ALN with LL. No significant differences were observed between MBL and SL, or for the superficial cervical dissections.

CLINICAL RELEVANCE

Peripheral lymphadenectomies are time consuming and difficult for veterinarians in early stages of surgical training. Little surgical guidance is provided within current literature. Geometric, landmark-guided lymphadenectomies may improve LN identification success and reduce surgical time, tissue trauma, and procedure difficulty, which could encourage their clinical application.

Laparoscopic ultrasonography of the liver is feasible and safe in dogs

OBJECTIVE

To describe the feasibility and technique for performing laparoscopic ultrasound (LUS) of the liver in dogs.

ANIMALS

12 client-owned dogs presenting for elective laparoscopic surgery from January 1, 2022, to October 31, 2022.

METHODS

Laparoscopic exploration and LUS of the liver were performed in all dogs. Dogs were positioned in reverse Trendelenburg and laterally rotated to facilitate access to all liver lobes. Time to perform laparoscopic exploration and LUS, ability to visualize and access each liver lobe entirely, and any complications were recorded. Each dog underwent an elective laparoscopic procedure. The surgeon completed a National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after surgery.

RESULTS

Mean body weight was 25.9 kg (SD, ± 4.1 kg; range, 5.7 to 62 kg). All liver lobes were scanned to the level of the hilus in 10/12 dogs. In 2 dogs, the caudate lobe could not be completely imaged. Median time to perform LUS was 9 minutes (IQR, 5 to 16.5 minutes), and median NASA-TLX score was 9/100 (IQR, 6.3 to 20). There was a significantly strong negative correlation between time to perform LUS (r = -0.77; P = .0037) and NASA-TLX score (r = -0.84; P = .0006) with trial number. Minor complications occurred in 2 dogs during laparoscopic exploration. No complications occurred during LUS.

CLINICAL RELEVANCE

LUS was feasible and safe in all dogs. The right lateral and caudate lobes were occasionally challenging to access. Technical demand and time to perform LUS improved with experience, suggesting a learning curve. Evaluation of LUS in dogs with clinical disease is warranted.

Preputial Shortening Reconstruction Surgery in a Dog with a Micropenis and Prepuce-to-Penis Size Disparity

A 1 yr old castrated male shih tzu was referred for recurrent urinary tract infections (UTI), prostatitis, and urine dribbling that was not responsive to medical management. Physical examination and computed tomography scan revealed a micropenis with a disproportionately high prepuce-to-penis ratio. Preputial shortening with a hexagonal, full thickness preputial resection followed by preputial anastomosis was performed. The dog recovered from surgery with no complications. Urine dribbling persisted in the short-term postoperative period, but the patient achieved significant clinical improvement and resolution of his urine dribbling and recurrent UTIs at the 1 yr follow-up. In conclusion, this surgical technique was able to successfully restore quality of life in a dog with a micropenis, and preputial shortening should be considered in cases of recurrent UTIs where there is significant disparity between the size of the penis and the prepuce.

Superficial anatomic landmarks can be used to triangulate the location of canine peripheral lymphocentrums: superficial cervical, axillary, and superficial inguinal

OBJECTIVE

To utilize the geometry of superficial anatomic landmarks to guide incisional location and orientation for peripheral lymphadenectomy, document deep anatomic landmarks for lymphocentrum identification, and develop novel surgical approaches to the superficial cervical, axillary, and superficial inguinal lymphocentrums in dogs.

ANIMALS

12 canine cadavers.

PROCEDURES

2 cadavers were used for a pilot investigation to determine optimal body positioning, select superficial anatomic landmarks for lymphocentrum identification, and evaluate novel surgical approaches to the 3 lymphocentrums. These lymphocentrums were then dissected in 10 additional cadavers using these novel surgical approaches. Measurements of the distances from lymphocentrum to landmark and between landmarks were obtained for each lymphocentrum. Deep anatomic landmarks were recorded for each dissection. The mean and SD were calculated for each measurement and used to develop geometric guidelines for estimating the location of each lymphocentrum for these surgical approaches.

RESULTS

Each peripheral lymphocentrum was found in the same location relative to the respective, predetermined, superficial, anatomic boundaries in all cadavers. Briefly, the superficial landmarks to each lymphocentrum were as follows: (1) superficial cervical: wing of atlas, acromion process of scapula, greater tubercle of humerus; (2) axillary: caudal border of transverse head of superficial pectoral muscle, caudal triceps muscle, ventral midline; and (3) superficial inguinal: origin of pectineus muscle, ipsilateral inguinal mammary gland, ventral midline. The proposed superficial and deep surgical landmarks were identified within every cadaver. The previously undescribed surgical approaches were effective for lymphocentrum identification.

CLINICAL RELEVANCE

Anatomic landmarks provided in this study may help reduce surgical time and tissue trauma during peripheral lymphadenectomy in dogs. This study was also the first to describe a surgical approach to the superficial inguinal lymphocentrum and ventral approaches to the superficial cervical and axillary lymphocentrums and provided previously unpublished anatomic landmarks for a lateral approach to the superficial cervical lymphocentrum.

Risk factors for intraoperative hemorrhage and perioperative complications and short- and long-term outcomes during surgical patent ductus arteriosus ligation in 417 dogs

OBJECTIVE

To evaluate the short- and long-term outcomes of dogs undergoing surgical ligation for a left-to-right shunting patent ductus arteriosus (PDA), identify risk factors for intraoperative hemorrhage and intra- and postoperative complications, and report overall mortality rates.

ANIMALS

417 client-owned dogs undergoing surgical ligation for a left-to-right shunting PDA between January 2010 and January 2020.

PROCEDURES

Data recorded included patient signalment, echocardiogram findings, intraoperative complications and mortality, postoperative complications, and short- and long-term outcomes.

RESULTS

There was no association between age and risk of intraoperative hemorrhage (P = .7), weight and intraoperative hemorrhage (P = .96), or increasing left atrium-to-aortic (LA:Ao) ratio and intraoperative hemorrhage (P = .08). Intraoperative hemorrhage occurred in 10.8% of patients. Intraoperative mortality was 2%. Ninety-five percent of dogs experiencing intraoperative hemorrhage survived to discharge. Survival to discharge was 97%. One- and 5-year survival rates were 96.4% and 87%, respectively.

CLINICAL RELEVANCE

Surgical ligation for a left-to-right shunting PDA is recommended due to the good long-term prognosis. Certain preoperative factors such as age, weight, and the presence and degree of mitral valve regurgitation had no detectable association with risks of intraoperative hemorrhage and, therefore, should not preclude surgical treatment for a left-to-right shunting PDA. Future studies are needed to further assess the association between increasing LA:Ao ratio and risk of intraoperative hemorrhage.

A quantitative evaluation of the effect of foreign body obstruction and enterectomy technique on canine small intestinal microvascular health

OBJECTIVE

To investigate sidestream dark field (SDF) videomicroscopy as an objective measure of intestinal viability and determine the effects of enterectomy techniques on intestinal microvasculature in dogs with foreign body obstructions.

STUDY DESIGN

Prospective, randomized, clinical trial.

ANIMALS

A total of 24 dogs with an intestinal foreign body obstruction and 30 systemically healthy dogs.

METHODS

An SDF videomicroscope imaged the microvasculature at the site of the foreign body. Subjectively viable intestine received an enterotomy whereas nonviable intestine received an enterectomy using a handsewn (4-0 polydioxanone, simple continuous) or a functional end-to-end stapled technique (GIA 60 blue, TA 60 green) was used on an alternating basis. The microvasculature adjacent to the enterectomy was interrogated. Quantitative measures of microvascular health were calculated for each site and compared with healthy dogs.

RESULTS

Microvascular density (mean ± SD) at the site of obstruction (140.84 ± 77.40) was lower than healthy controls (251.72 ± 97.10, p < .01). There was no difference in microvascular parameters (density or perfused boundary region, PBR) between obstructed dogs with subjectively viable and nonviable intestine (p > .14). The density (p = .66) and PBR of microvessels (p = .76) adjacent to the sutured enterectomy or TA green staple line did not differ.

CONCLUSION

Sidestream dark field videomicroscopy can identify obstructed intestine and quantitate the severity of microvascular compromise. Handsewn and stapled enterectomies equally preserve perfusion.

CLINICAL SIGNIFICANCE

Stapled enterectomies do not lead to greater vascular compromise than handsewn enterectomies.

Comparison of surgeon experience using simple interrupted and simple continuous suture patterns in intestinal resection and anastomosis

This experimental study compared leak pressures and completion time of intestinal anastomoses performed by novice veterinarians and a Board-certified surgeon using simple interrupted and simple continuous suture patterns. Grossly normal jejunal segments (n = 108) from 6 fresh canine cadavers were used to harvest 8-cm cooled canine cadaveric jejunal segments that were randomly assigned to a control group (12 segments) and 4 treatment groups (24 segments/group, 12 constructs/group): i) simple interrupted anastomoses performed by a Board-certified surgeon (BSI); ii) simple continuous anastomoses performed by a Board-certified surgeon (BSC); iii) simple interrupted anastomoses performed by novice veterinarians (NSI); and iv) simple continuous anastomoses performed by novice veterinarians (NSC). Median (range) initial leak pressure (ILP) for control was 400.2 mmHg (226.0 to 500.0 mmHg), BSI 37.4 (14.4 to 124.0), BSC 32.5 (13.4 to 91.0), NSI 36.5 (22.9 to 62.0), and NSC 47.5 (8.9 to 120.0). No difference was noted between experience (P = 0.73, P = 0.53), suture technique (P = 0.07, P = 0.38), or across treatment groups (P = 0.17, P = 0.94), for ILP or MIP (maximum intraluminal pressure), respectively. Time to construct completion differed based on suture technique (P < 0.0001) and experience (P < 0.0001). The median and mean ILP of all anastomoses exceeded physiologic intraluminal peristaltic pressures. Simple continuous anastomoses were faster to complete overall. Both handsewn anastomosis techniques are appropriate for intestinal anastomoses.

Prospective evaluation of lymphatic embolization as part of the treatment in dogs with presumptive idiopathic chylothorax

OBJECTIVE

To describe the embolization technique and short-term clinical outcome in dogs undergoing lymphatic embolization (LE) as part of treatment for presumptive idiopathic chylothorax (IC). Additionally, to document findings in computed tomography lymphangiography (CTLa) following embolization.

STUDY DESIGN

Prospective case series ANIMALS: Eight client-owned dogs.

METHODS

Dogs underwent CTLa followed by thoracic duct ligation (TDL), pericardiectomy (PC) and LE. A mixture of 3:1 lipiodol: n-butyl cyanoacrylate embolic solution was injected through a catheterized mesenteric lymphatic vessel via limited abdominal approach using intraoperative fluoroscopy. CTLa was scheduled for 12 weeks postoperatively, and long-term follow-up was obtained via telephone contact.

RESULTS

LE was technically successful in six of the eight dogs; and clinically successful in five of the six dogs. In the unsuccessful dog, a diagnosis of lymphangiosarcoma was determined, and the owners elected for euthanasia. Five dogs who underwent successful LE underwent CTLa at 12 weeks. Complete resolution of pleural effusion occurred in three dogs and scant pleural effusion in two dogs. A robust lymphatic embolus preventing antegrade continuation of radiocontrast was documented in all five dogs. Five of the six dogs that underwent LE, are alive and clinically normal at 358-960 days postoperatively.

CONCLUSIONS

LE is feasible as part of treatment for dogs with IC. Additionally, a robust lymphatic embolus and lack of radiocontrast flow past the embolus was documented at 12 weeks following surgery.

CLINICAL SIGNIFICANCE

LE has the potential to reduce surgical failure by reducing efferent lymphatic chyle flow, occluding missed lymphatic branches and preventing the development of collateral branches.

Veterinary house officer perceptions of dimensions of well-being during postgraduate training

OBJECTIVE

To describe veterinary house officers’ perceptions of dimensions of well-being during postgraduate training and to identify potential areas for targeted intervention.

SAMPLE

303 house officers.

PROCEDURES

A 62-item questionnaire was generated by use of an online platform and sent to house officers at participating institutions in October 2020. Responses were analyzed for trends and associations between selected variables.

RESULTS

239 residents, 45 rotating interns, and 19 specialty interns responded to the survey. The majority of house officers felt that their training program negatively interfered with their exercise habits, diet, and social engagement. House officers reported engaging in exercise significantly less during times of clinical responsibility, averaging 1.6 exercise sessions/wk (SD ± 0.8) on clinical duty and 2.4 exercise sessions/wk (SD ± 0.9) when not on clinical duty (P < 0.001). Ninety-four percent of respondents reported experiencing some degree of anxiety regarding their physical health, and 95% of house officers reported feeling some degree of anxiety regarding their current financial situation. Overall, 47% reported that their work-life balance was unsustainable for > 1 year; there was no association between specialty and sustainability of work-life balance. Most house officers were satisfied with their current training program, level of clinical responsibility, and mentorship.

CLINICAL RELEVANCE

Veterinary house officers demonstrated a poor balance between the demands of postgraduate training and maintenance of personal health. Thoughtful interventions are needed to support the well-being of veterinary house officers.

Dogs ≥ five years of age at the time of congenital extrahepatic portosystemic shunt diagnosis have better long-term outcomes with surgical attenuation than with medical management alone

OBJECTIVE

To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only.

ANIMALS

351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age.

PROCEDURES

Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time.

RESULTS

351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%.

CLINICAL RELEVANCE

Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.

Distribution of histopathologic types of primary pulmonary neoplasia in dogs and outcome of affected dogs: 340 cases (2010-2019)

OBJECTIVE

To provide updated information on the distribution of histopathologic types of primary pulmonary neoplasia in dogs and evaluate the effect of postoperative adjuvant chemotherapy in dogs with pulmonary carcinoma.

ANIMALS

340 dogs.

PROCEDURES

Medical records of dogs that underwent lung lobectomy for removal of a primary pulmonary mass were reviewed, and histopathologic type of lesions was determined. The canine lung carcinoma stage classification system was used to determine clinical stage for dogs with pulmonary carcinoma.

RESULTS

Pulmonary carcinoma was the most frequently encountered tumor type (296/340 [87.1%]), followed by sarcoma (26 [7.6%]), adenoma (11 [3.2%]), and pulmonary neuroendocrine tumor (5 [1.5%]); there was also 1 plasmacytoma and 1 carcinosarcoma. Twenty (5.9%) sarcomas were classified as primary pulmonary histiocytic sarcoma. There was a significant difference in median survival time between dogs with pulmonary carcinomas (399 days), dogs with histiocytic sarcomas (300 days), and dogs with neuroendocrine tumors (498 days). When dogs with pulmonary carcinomas were grouped on the basis of clinical stage, there were no significant differences in median survival time between dogs that did and did not receive adjuvant chemotherapy.

CLINICAL RELEVANCE

Results indicated that pulmonary carcinoma is the most common cause of primary pulmonary neoplasia in dogs; however, nonepithelial tumors can occur. Survival times were significantly different between dogs with pulmonary carcinoma, histiocytic sarcoma, and neuroendocrine tumor, emphasizing the importance of recognizing the relative incidence of these various histologic diagnoses. The therapeutic effect of adjuvant chemotherapy in dogs with pulmonary carcinoma remains unclear and warrants further investigation.

Incidence, survival time, and surgical treatment of parathyroid carcinomas in dogs: 100 cases (2010-2019)

OBJECTIVE

To evaluate outcomes of dogs with parathyroid carcinoma (PTC) treated by surgical excision and to describe the incidence of postoperative hypocalcemia, degree of hypocalcemia, duration of hospitalization, duration of calcium supplementation, and survival time.

ANIMALS

100 client-owned dogs with PTC admitted to academic, referral veterinary institutions.

PROCEDURES

In a retrospective multi-institutional study, medical records of dogs undergoing surgical excision of PTC between 2010 to 2019 were reviewed. Signalment, relevant medical history, clinical signs, clinicopathologic testing, imaging, surgical findings, intraoperative complications, histologic examination, and survival time were recorded.

RESULTS

100 dogs with PTC were included, and 96 dogs had clinical or incidental hypercalcemia. Common clinical signs included polyuria (44%), polydipsia (43%), hind limb paresis (22%), lethargy (21%), and hyporexia (20%). Cervical ultrasonography detected a parathyroid nodule in 91 of 91 dogs, with a single nodule in 70.3% (64/91), 2 nodules in 25.3% (23/91), and ≥ 3 nodules in 4 (4/91)% of dogs. Hypercalcemia resolved in 89 of 96 dogs within 7 days after surgery. Thirty-four percent of dogs developed hypocalcemia, on the basis of individual analyzer ranges, within 1 week after surgery. One dog had metastatic PTC to the prescapular lymph node, and 3 dogs were euthanized for refractory postoperative hypocalcemia. Estimated 1-, 2-, and 3-year survival rates were 84%, 65%, and 51% respectively, with a median survival time of 2 years.

CONCLUSIONS AND CLINICAL RELEVANCE

Excision of PTC results in resolution of hypercalcemia and excellent long-term tumor control. Surgical excision of PTC is recommended because of resolution of hypercalcemia and a good long-term prognosis. Future prospective studies and long-term follow-up are needed to further assess primary tumor recurrence, metastasis, and incidence of postoperative hypocalcemia.

Ex vivo comparison of leak testing of canine jejunal enterotomies: Saline infusion versus air insufflation

OBJECTIVE

To compare the ability to detect leakage of enterotomy closures by intraluminal injection of saline or air.

STUDY DESIGN

Ex vivo study.

ANIMALS

Grossly normal jejunal segments (n = 60) from five fresh canine cadavers.

METHODS

Eight-centimeter jejunal segments were randomly assigned to two control (saline control [n = 5], air control [5]) and two treatment groups (injection of saline [n = 25] or air [25] after enterotomies were closed in a simple continuous pattern using 4-0 glycomer 631). Initial leak pressure (ILP, mean ± SD), maximum intraluminal pressure (MIP), and leakage location were compared. For all air insufflation constructs, the volume of air insufflated at the time of initial leakage was recorded.

RESULTS

The ILPs of control segments did not differ whether injected with saline (405.71 ± 56.97 mmHg) or air (376.84 ± 42.54, p = 1.00). Enterotomy closures leaked at lower pressures when injected with air (ILP: 68.52 ± 6.56) compared to saline (87.76 ± 5.20, p = .03). Similar results were obtained when comparing MIPs. A moderate association (r = .51) was identified between volume of air infused and ILPs. The strength of the association improved when stratified by cadaver. The location of leakage-most commonly suture tracks-was identified for all air constructs and for 14 of 25 saline constructs.

CONCLUSION

Enterotomy closures leaked at lower pressures after intraluminal injection of air compared to saline.

CLINICAL SIGNIFICANCE

Intraoperative leak testing of small intestinal enterotomy closures may be rendered more sensitive and precise by the use of air instead of saline as the infusate.

Laparoscopic gonadectomy in a dog with 78,XX/78,XY chimerism and underdeveloped reproductive organs

CASE DESCRIPTION

A 1-year-old externally sexually intact female Great Dane was referred for further evaluation of abnormal and underdeveloped internal reproductive organs.

CLINICAL FINDINGS

Physical examination findings included a cranioventrally displaced vulva and a grade 2/6 left apical systolic heart murmur. No uterus or ovaries were identified during abdominal ultrasonography. Computed tomography with retrograde vaginourethrography revealed an underdeveloped uterus and possible left intra-abdominal gonad. Karyotyping revealed mixed sex chromosomes (70% XY and 30% XX). Analysis of a serum sample yielded positive results for anti-Müllerian hormone; other findings included mid range estradiol concentration (48.2 pg/mL [within reference intervals for sexually intact and neutered males and females]), low progesterone concentration (< 0.2 ng/mL [within reference intervals for anestrous females]), and low testosterone concentration (< 20 ng/dL [similar to the expected concentration in neutered males]). Overall, the results of the sex hormone analyses were consistent with findings for either a sexually intact female or a neutered male dog. The dog's cardiac structure and function were echocardiographically normal.

TREATMENT AND OUTCOME

The dog was anesthetized and underwent laparoscopic gonadectomy. The gonads, although abnormal and underdeveloped, were readily identified intraoperatively and successfully removed. On the basis of histologic findings, the removed gonads were confirmed to be rudimentary testicles. The dog recovered from anesthesia and surgery without complications.

CLINICAL RELEVANCE

Laparoscopic surgery was effective for visualization of abnormal and hypoplastic reproductive organs when abdominal ultrasonography and CT were of limited diagnostic usefulness, and laparoscopic surgery allowed straightforward gonadectomy in a 78,XX/78,XY chimeric dog.

Evaluation of intraoperative leak testing of small intestinal anastomoses performed by hand-sewn and stapled techniques in dogs: 131 cases (2008-2019)

OBJECTIVE

To compare the rate of postoperative dehiscence on the basis of intraoperative anastomotic leak test results (ie, positive or negative for leakage or testing not performed) between dogs that underwent hand-sewn anastomosis (HSA) or functional end-to-end stapled anastomosis (FEESA) of the small intestine.

ANIMALS

131 client-owned dogs that underwent 144 small intestinal anastomoses (94 FEESA and 50 HSA).

PROCEDURES

Medical records were searched to identify dogs that had undergone a small intestinal anastomosis (HSA or FEESA) from January 2008 through October 2019. Data were collected regarding signalment, indication for surgery, location of the anastomosis, surgical technique, the presence of preoperative septic peritonitis, performance of intraoperative leak testing, development of postoperative dehiscence, and duration of follow-up.

RESULTS

Intraoperative leak testing was performed during 62 of 144 (43.1%) small intestinal anastomoses, which included 26 of 94 (27.7%) FEESAs and 36 of 50 (72.0%) HSAs. Thirteen of 144 (9.0%) anastomoses underwent dehiscence after surgery (median, 4 days; range, 2 to 17 days), with subsequent septic peritonitis, including 10 of 94 (10.6%) FEESAs and 3 of 50 (6.0%) HSAs. The incidence of postoperative dehiscence was not significantly different between FEESAs and HSAs; between anastomoses that underwent intraoperative leak testing and those that did not, regardless of anastomotic technique; or between anastomoses with positive and negative leak test results. Hand-sewn anastomoses were significantly more likely to undergo leak testing than FEESAs. Preoperative septic peritonitis, use of omental or serosal reinforcement, preoperative serum albumin concentration, and surgical indication were not significantly different between anastomotic techniques.

CONCLUSIONS AND CLINICAL RELEVANCE

Performance of intraoperative anastomotic leak testing, regardless of the anastomotic technique, was not associated with a reduction in the incidence of postoperative anastomotic dehiscence.

Feasibility of laparoscopic liver lobectomy in dogs

OBJECTIVE

To determine the feasibility of laparoscopic liver lobectomy (LLL) in dogs by using canine cadavers and to describe the clinical application in dogs with liver disease.

STUDY DESIGN

Ex vivo experiment and descriptive case series.

SAMPLE POPULATION

Twelve canine cadavers and six client-owned dogs.

METHODS

Cadavers underwent LLL with an endoscopic stapler. The percentage of liver lobe resected was determined by volume. The distance from the staple line to hilus was measured. Medical records of dogs undergoing LLL were reviewed.

RESULTS

In cadavers ≤15 kg, left lateral lobectomy completeness was 87.3% (84.6%-96.6%), and remaining median (interquartile range) hilar length was 1 cm (0.25-1.75). Left medial lobectomy completeness was 72.5% (66.7%-80%), and remaining hilar length was 1.6 cm (0.47-1.75). Central division resection completeness was 68.3% (60%-92.9%), and remaining hilar length was 2.7 cm (0.8-5). Laparoscopic liver lobectomy was not feasible for right division lobes and in cadavers >15 kg. Five dogs with peripheral quadrate or left lateral lobe masses underwent stapled, partial laparoscopic lobectomy (30%-90%). One dog underwent stapled, left lateral lobectomy (90%) after open procedure conversion. Histopathological diagnoses included hepatocellular carcinoma (3), nodular hyperplasia (1), biliary cyst adenoma (1), and fibrosis (1).

CONCLUSION

Laparoscopic liver lobectomy of the left and central divisions is feasible in cadavers ≤15 kg with an endoscopic stapler. Partial LLL of the left and central divisions is feasible in select dogs with liver disease.

CLINICAL SIGNIFICANCE

Laparoscopic liver lobectomy may be a viable alternative to laparotomy in small-to-medium size dogs with peripheral liver masses of the left and central divisions.

Ligation of the ligamentum arteriosum and aberrant left subclavian artery in five dogs in which persistent right aortic arch had been diagnosed

OBJECTIVE

To determine and report the diagnosis, treatment, and outcome in dogs with persistent right aortic arch (PRAA) with an aberrant left subclavian artery (ALS) that underwent thoracoscopic surgery.

ANIMALS

Dogs with PRAA and an ALS (n = 5).

STUDY DESIGN

Short case series.

METHODS

Medical records were reviewed from 2014 to 2019. Dogs that underwent thoracoscopy for PRAA with an ALS at an academic referral hospital were included. Signalment, clinical signs, diagnostic imaging, surgical approach, complications, and short- and long-term outcomes were recorded.

RESULTS

Persistent right aortic arch with an ALS was identified in five dogs. Dogs initially underwent a three-port intercostal thoracoscopic approach, and an intercostal thoracotomy was performed in converted cases. In all five dogs, the ligamentum arteriosum (LA) and ALS were divided; three were performed by a thoracoscopy alone. Two cases were converted because of poor exposure (1) and requirement to temporary occlude an ALS (1). The ALS was ligated and divided in all dogs without apparent negative effects. No intraoperative or postoperative complications occurred. Four dogs had resolution of regurgitation, three of which required diet modification. One dog had reported regurgitation when it was excited. Median follow-up was 188 days (range, 150-1133).

CONCLUSION

Ligation and division of both the LA and the ALS in all dogs in this case series was safe and allowed for improvement in clinical signs and good to excellent long-term outcomes. In addition, both thoracoscopy and thoracotomy were used safely and successfully for ligation and transection of the LA and ALS in all dogs.

Successful Treatment of Congenital Lobar Emphysema in Multiple Lung Lobes in an English Bulldog Puppy

A 5 mo old male intact English bulldog was evaluated at a veterinary referral hospital for acute respiratory distress and chronic difficulty breathing. Thoracic radiographs revealed multifocal pulmonary hyperinflation and hyperlucency suspected in the left caudal and accessory lung lobes. A thoracic computed tomography scan identified severe diffuse enlargement of the caudal subsegment of the left cranial lung lobe and the dorsal process of the accessory lung lobe, with parenchymal hypoattenuation, rounded margins, and thin pulmonary vessels. Based on clinical signs and imaging findings, he was diagnosed with suspect congenital lobar emphysema in multiple lung lobes. A median sternotomy was performed, which revealed a hyperinflated, emphysematous left cranial lung lobe (caudal subsegment) and accessory lung lobe for which two lung lobectomies were performed. The remaining lung lobes were small and atelectatic. Histopathology revealed bronchial cartilage hypoplasia and aplasia and findings consistent with congenital lobar emphysema. The puppy recovered well from surgical treatment of congenital lobar emphysema, requiring multiple lung lobectomies, with subsequent computed tomography-evidenced re-expansion of the remaining lung lobes 3 mo after surgery. The patient is still alive 1 yr after surgery with a normal activity level and no evidence of respiratory compromise.

Evaluation of jejunal microvasculature of healthy anesthetized dogs with sidestream dark field video microscopy

OBJECTIVE

To determine the feasibility of sidestream dark field (SDF) video microscopy for the evaluation of the jejunal microvasculature of healthy dogs.

ANIMALS

30 healthy sexually intact female shelter dogs anesthetized for ovariohysterectomy.

PROCEDURES

Preoperative physical and clinicopathologic assessments were performed to confirm health status. Then healthy dogs were anesthetized, and the abdomen was incised at the ventral midline for ovariohysterectomy and jejunal microvasculature evaluation. An SDF video microscope imaged the microvasculature of 2 sites of a portion of the jejunum, and recorded videos were analyzed with software capable of quantitating parameters of microvascular health. Macrovascular parameters (heart rate, respiratory rate, and hemoglobin oxygen saturation) were also recorded during anesthesia.

RESULTS

Quantified jejunal microvascular parameters included valid microvascular density (mean ± SD, 251.72 ± 97.10 μm/mm), RBC-filling percentage (66.96 ± 8.00%), RBC column width (7.11 ± 0.72 μm), and perfused boundary region (2.17 ± 0.42 μm). The perfused boundary region and RBC-filling percentage had a significant negative correlation. Strong to weak positive correlations were noted among the perfused boundary regions of small-, medium-, and large-sized microvessels. No significant correlations were identified between microvascular parameters and age, body weight, preoperative clinicopathologic results, or macrovascular parameters.

CONCLUSIONS AND CLINICAL RELEVANCE

Interrogation of the jejunal microvasculature of healthy dogs with SDF video microscopy was feasible. Results of this study indicated that SDF video microscopy is worth additional investigation, including interrogation of diseased small intestine in dogs.

Comparison of intestinal leak pressure between cadaveric canine and commercial synthetic intestinal tissue that did and did not undergo enterotomy

OBJECTIVE

To compare initial leak pressure (ILP) between cadaveric canine and synthetic small intestinal segments that did and did not undergo enterotomy.

SAMPLE

Eight 8-cm grossly normal jejunal segments from 1 canine cadaver and eight 8-cm synthetic small intestinal segments.

PROCEDURES

Intestinal segments were randomly assigned to undergo enterotomy (6 cadaveric and 6 synthetic segments) or serve as untreated controls (2 cadaveric and 2 synthetic segments). For segments designated for enterotomy, a 2-cm full-thickness incision was created along the antimesenteric border. The incision was closed in a single layer with 4-0 suture in a simple continuous pattern. Leak testing was performed with intestinal segments occluded at both ends and infused with dilute dye solution (999 mL/h) until the solution was observed leaking from the suture line or serosal tearing occurred. Intraluminal pressure was continuously monitored. The ILP at construct failure was compared between cadaveric and synthetic control segments and between cadaveric and synthetic enterotomy segments.

RESULTS

Mean ± SD ILP did not differ significantly between cadaveric (345.11 ± 2.15 mm Hg) and synthetic (329.04 ± 24.69 mm Hg) control segments but was significantly greater for cadaveric enterotomy segments (60.77 ± 15.81 mm Hg), compared with synthetic enterotomy segments (15.03 ± 6.41 mm Hg).

CONCLUSIONS AND CLINICAL RELEVANCE

Leak testing should not be used to assess the accuracy or security of enterotomy suture lines in synthetic intestinal tissue. Synthetic intestinal tissue is best used for students to gain confidence and proficiency in performing enterotomies before performing the procedure on live animals.

Radiographic tracheal dimensions in brachycephalic breeds before and after surgical treatment for brachycephalic airway syndrome

The objective of this retrospective study was to compare preoperative and postoperative tracheal measurements in brachycephalic dogs undergoing surgical treatment of brachycephalic airway syndrome (BAS) using 2 radiographic methods (TD:TI and TT:3R). Medical records of 24 brachycephalic dogs with surgically corrected BAS were reviewed. Represented breeds included English bulldogs (n = 9), French bulldogs (n = 9), pugs (n = 5), and a Japanese chin (n = 1). Dogs with BAS that had postoperative thoracic radiographs ≤ 1 week after surgery showed no significant difference in the mean TD:TI ratios (P = 0.06) or mean TT:3R ratios (P = 0.19) when comparing preoperative to postoperative ratios. Dogs that had postoperative thoracic radiographs > 1 week after surgery showed no significant difference in the mean TD:TI ratios (P = 0.06) or mean TT:3R ratios (P = 0.32) when comparing preoperative to postoperative ratios. According to these findings, surgical correction for BAS does not resolve or improve tracheal hypoplasia in brachycephalic breeds.

Otoscopic evaluation of epithelial remnants in the tympanic cavity after total ear canal ablation and lateral bulla osteotomy

OBJECTIVE

To determine the ability to detect the presence of epithelial remnants after total ear canal ablation (TECA) and lateral bulla osteotomy (LBO) with endoscopy and to identify the most common locations of epithelial remnants after tympanic curettage.

STUDY DESIGN

Experimental study.

ANIMALS

Five fresh canine cadavers with no gross evidence of middle ear disease.

METHODS

Ten TECA-LBO were performed by four surgeons. After tympanic curettage, a 1.9-mm rigid 30° endoscope was inserted into the rostral, caudal, dorsal, ventral, and medial sections of the tympanic cavity. Three observers evaluated otoscopic images for epithelial remnants in each compartment. The median distribution of epithelial remnants was calculated for each section of the tympanic cavity with a three-dimensional tympanic cavity model.

RESULTS

Epithelial remnants were identified in at least one of the five areas of the tympanic cavity after each TECA-LBO. The rostral section contained the most epithelial remnants (35.6%), while the medial section contained the least amount (1.8%).

CONCLUSION

Use of a 1.9-mm rigid endoscope was an effective method to evaluate all sections of the tympanic cavity after curettage in TECA-LBO. Epithelial remnants were consistently found after TECA-LBO, especially in the rostral compartment.

CLINICAL SIGNIFICANCE

Intraoperative endoscopy should be considered to improve removal of epithelium after initial TECA-LBO or revision surgeries.

Gastrointestinal thickness, duration, and leak pressure of six intestinal anastomoses in dogs

OBJECTIVE

To compare leak pressures and construct completion time of six intestinal anastomoses and report normal canine gastrointestinal thickness.

STUDY DESIGN

Experimental study.

ANIMALS

Grossly normal jejunal segments (n = 140) from 10 fresh canine cadavers.

METHODS

Gastrointestinal thickness was recorded. Eight-centimeter cooled canine cadaveric jejunal segments were randomly assigned to a control group (20 segments) and six treatment groups (20 segments/group [10 constructs/group]): (1) handsewn anastomosis (HSA), (2) functional end-to-end stapled anastomosis (FEESA)-blue thoracoabdominal (TA; FEESA-TAB), (3) FEESA-green TA (FEESA-TAG), (4) FEESA TA-gastrointestinal anastomosis (GIA), (5) FEESA with suture oversew (FEESA-O), and (6) skin staples (SS). Construct assembly time, initial leak pressure (ILP), maximum intraluminal pressure (MIP), and leakage location were compared.

RESULTS

Initial leak pressures (mean ± SD) for control (308.38 ± 115.91 mm Hg), HSA (41.96 ± 15.97), FEESA-TAB (31.71 ± 15.71), FEESA-TAG (27.24 ± 14.11), FEESA-GIA (25.62 ± 11.22), FEESA-O (31.01 ± 17.38), and SS (44.42 ± 28.88) groups were compared. No difference in ILP (P > .24) or MIP (P > .17) was detected between treatment groups. Sutured anastomoses took up to 10 times longer to complete (P = .0025). The stomach, duodenum, jejunum, and ileum mural thicknesses (mean ± SD) were 3.99 ± 0.44 mm, 2.34 ± 0.16, 2.49 ± 0.28, and 2.30 ± 0.31, respectively.

CONCLUSION

The ILP of all anastomoses exceeded maximum intraluminal peristaltic pressures. Stapled anastomoses were faster to complete.

CLINICAL SIGNIFICANCE

All anastomoses may be considered when performing an intestinal resection and anastomosis, with stapled anastomoses resulting in a shorter surgical time. Canine intestinal thickness may warrant use of a larger staple size.

In vitro holding strength of the laparoscopic Miller's knot compared with open Miller's knot, open surgeon's throw, and laparoscopic surgeon's throw in a vascular pedicle model

OBJECTIVE

To compare in vitro knot holding strength of the laparoscopic Miller's knot (LMK), open Miller's knot (MK), open surgeon's throw (Sx), and laparoscopic surgeon's throw (LSx) in a vascular pedicle model when used as the first throw for vascular ligation.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Ten constructs each of the Miller's knot and surgeon's throw performed openly and laparoscopically with 2-0 polyglyconate suture.

METHODS

Knot holding strengths of the LMK, MK, LSx, and Sx knots were evaluated on balloon dilation catheters used as vascular pedicle models. Laparoscopic knots were tied in a laparoscopic box trainer. Knot constructs were pressure tested to failure. Results were compared by Kruskal-Wallis and Steel-Dwass comparisons.

RESULTS

Both MK and LMK had mean leakage pressures above 300 mm Hg. The MK leaked at higher pressure than all other knots, including the LMK (P < .001). The LMK leaked at greater pressures compared with the Sx and the LSx (P < .001). No difference was detected between leaking pressures of the Sx and the LSx (P = .226), with both leaking at pressures below 40 mm Hg.

CONCLUSION

The LMK created a more secure first throw compared with the Sx and leaked at supraphysiologic pressures.

CLINICAL SIGNIFICANCE

The LMK has excellent knot holding strength on a vascular pedicle model and may be further evaluated for clinical application.

A Review of Normal Intestinal Healing, Intestinal Anastomosis, and the Pathophysiology and Treatment of Intestinal Dehiscence in Foreign Body Obstructions in Dogs

Small intestinal anastomoses are commonly performed in veterinary medicine following resection of diseased or devitalized intestinal tissue. Traditionally, suture has been employed to anastomose intestinal ends. However, use of intestinal staplers has become increasingly popular due to the ability to produce a rapid anastomosis with purported superior healing properties. Under normal conditions, intestinal healing occurs in three phases: inflammatory, proliferative, and maturation. Dehiscence, a devastating consequence of intestinal anastomosis surgery, most often occurs during the inflammatory phase of healing where the biomechanical strength of the anastomosis is almost entirely dependent on the anastomotic technique (suture or staple line). The resulting septic peritonitis is associated with a staggering morbidity rate upwards of 85% secondary to the severe systemic aberrations and financial burden induced by septic peritonitis and requirement of a second surgery, respectively. Intraoperative and postoperative consideration of the multifactorial nature of dehiscence is required for successful patient management to mitigate recurrence. Moreover, intensive postoperative critical care management is necessitated and includes antibiotic and fluid therapy, vasopressor or colloidal support, and monitoring of the patient's fluid balance and cardiovascular status. An understanding of anastomotic techniques and their relation to intestinal healing will facilitate intraoperative decision-making and may minimize the occurrence of postoperative dehiscence.

The Pathophysiology of Small Intestinal Foreign Body Obstruction and Intraoperative Assessment of Tissue Viability in Dogs: A Review

Small intestinal foreign body obstructions occur commonly in dogs, accounting for 80% of all canine intestinal obstructions. Such obstructions induce local aberrations in secretion, absorption, and intestinal motility that can precipitate devastating systemic consequences, including a systemic inflammatory response, sepsis, and multiorgan dysfunction. Radiographic diagnosis is poorly sensitive relative to ultrasonography for diagnosing the presence of obstructive foreign material. Emergent surgical intervention is indicated for dogs with obstructive foreign material due to an inability to assess the degree of compromise of the intestinal wall that may precipitate intestinal perforation and to mitigate progression of life-threatening electrolyte and acid-base imbalances secondary to sequestration and emesis. Intraoperatively, an enterotomy or resection and anastomosis may be required to remove the obstructive material. A number of subjective and objective techniques for assessing the viability of intestinal tissue have been described due to the poor accuracy associated with surgeon assessment of color, peristalsis, pulsation, bleeding, and mural thickness alone. Such techniques have the potential to alter the surgeon's decision-making regarding performance of an enterotomy or resection and anastomosis, potentially reducing morbidity associated with intestinal surgery.

Successful Treatment of Urinary Bladder Hemangiosarcoma by Partial Cystectomy in a Dog

A 6 yr old neutered male German shepherd dog was evaluated at a veterinary referral hospital following diagnosis of uroabdomen of unknown origin. A positive-contrast retrograde urethrogram identified diffusely irregular margins of the urinary bladder but no active leakage of urine into the peritoneal cavity. An abdominal ultrasound identified severe thickening and loss of wall layering of the apex of the bladder. The dog was initially managed with an indwelling urinary catheter; however, when the catheter was removed 5 days later, the dog developed a recurrent uroabdomen after an episode of dysuria. Subsequent surgical exploration identified numerous (>5), small (1-2 cm), black cyst-like nodules within the bladder wall at the apex of the bladder. A partial cystectomy, removing approximately 65% of the cranial bladder, was performed. Histopathology and immunohistochemistry of the bladder identified hemangiosarcoma of the bladder wall with chronic neutrophilic and hemorrhagic cystitis. The dog recovered from surgery without major complication and is still alive 9 mo following surgery. To the authors' knowledge, this is the first report of successful treatment of canine bladder hemangiosarcoma by partial cystectomy in a dog.

Anatomic and volumetric characterization of the cisterna chyli using CT lymphangiography and computer-assisted design software in dogs with idiopathic chylothorax

The objectives of this retrospective, observational study were to characterize the anatomical features of the cisterna chyli (CC) in a cohort of dogs diagnosed with idiopathic chylothorax that underwent CT lymphangiography (CTLa), and to evaluate the feasibility of computer-assisted design (CAD) software to quantify volumetric measurements of the CC. Twenty-three client-owned dogs with idiopathic chylothorax were included. Additionally, CTLa was performed in three canine cadavers to assess the ability of CAD software to accurately acquire volumetric measurements. Injection sites, attenuation values, anatomic location, dimensions, and aortic diameter to CC ratio (Ao:CC) were recorded. Video records of video-assisted thoracic surgery (VATS) thoracic duct ligation (TDL) were reviewed in eight out of 23 dogs to compare operative and CTLa findings. The CC was dorsal and right-sided in 18 out of 23 dogs, located between L1 and L4 in 21 dogs, and extended as far cranially as T11 in two dogs. The median measurements for length, height, and width were 150.0, 5.5, and 13.3 mm, respectively. Median total volume was 1.82 mL. Median volumes to the right and left of the aorta were 1.46 and 0.49 mL, respectively (P = .014). Median total CC volume to body weight ratio (CC:bw) was 0.07 mL/kg. The presence of an intrathoracic CC was observed intraoperatively in six out of eight cases that underwent VATS TDL. Findings supported the use of CTLa and CAD as feasible methods for characterizing the CC in dogs diagnosed with chylothorax. These methods may facilitate interventional planning involving the CC such as embolization.

Initial leak pressures of four anastomosis techniques in cooled cadaveric canine jejunum

OBJECTIVE

To compare the effectiveness of four different intestinal anastomosis techniques at preventing leakage after enterectomy.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Grossly normal jejunal segments (N = 70) from three fresh canine cadavers.

METHODS

Eight-centimeter cooled canine cadaveric jejunal segments were randomly assigned to a control group (six segments) and four treatment groups (16 segments each [two segments/anastomotic construct]): (1) handsewn anastomosis (HSA), (2) barbed suture anastomosis (B-HSA), (3) stapled functional end-to-end anastomosis (SFEEA), and (4) stapled functional end-to-end anastomosis with an oversew (SFEEA-O). Control segments and anastomotic constructs were infused intraluminally to the point of leakage. Initial leak pressures were recorded and compared.

RESULTS

Initial leak pressures (median + range) for jejunal control segments, HSA, B-HSA, SFEEA, and SFEEA-O were 331.88 mmHg (range, 315.34-346.64), 35.17 (20.29-56.24), 24.99 (6.08-38.64), 28.77 (18.80-85.09), and 35.92 (12.05-80.71), respectively. No difference was detected between leak pressures of anastomosed segments (P = .35), all of which were more variable and lower than those of intact segments.

CONCLUSION

No difference in initial leak pressures was detected between the four anastomosis techniques tested in cooled canine cadaveric jejunum.

CLINICAL SIGNIFICANCE

All four anastomosis techniques evaluated in this study may be suitable in dogs.

Vascular ring anomalies in cats: 20 cases (2000-2018)

OBJECTIVE

To report the clinical characteristics, types of vascular ring anomalies (VRA), operative findings, complications, and survival after surgical treatment of cats with VRA.

STUDY DESIGN

Retrospective, multi-institutional case series.

ANIMALS

Client- or shelter-owned cats presenting to academic, referral veterinary institutions.

METHODS

Medical records of cats with VRA that underwent surgical treatment were reviewed. Signalment, relevant medical history, clinical signs, diagnostic imaging, surgical findings, complications, and survival were recorded.

RESULTS

Twenty cats with VRA were included. Vascular ring anomalies were most commonly (75% [15/20]) diagnosed in cats less than 1 year old, with no breed or sex predilection. Regurgitation was the most common clinical sign, present in 18 of 20 (90%) cats. A persistent right aortic arch was diagnosed in 17 of 20 (85%) cats, with concurrent aberrant left subclavian artery in four of the cats. Surgical treatment was associated with survival to discharge in 18 of 20 (90%) cats. Persistent clinical signs were reported in nine of 13 (69%) cats, and radiographic evidence of megaesophagus persisted in four of 13 (31%) cats, with a median follow-up of 275 days after discharge.

CONCLUSION

Persistent right aortic arch was the most commonly diagnosed VRA in cats in this series, although multiple anomalies were observed. Surgical treatment of VRA in cats was associated with a high survival to discharge, although persistence of clinical signs and megaesophagus was noted in 69% and 31% of the cats, respectively.

CLINICAL SIGNIFICANCE

Surgical treatment of VRA in cats is associated with a high survival rate; however, persistence of clinical signs is an expected outcome.

Intestinal surgery in small animals: historical foundations, current thinking, and future horizons

Intestinal wounds require precise closure after intestinal biopsy, enterotomy, or enterectomy in small animals. Preexisting factors such as intra-abdominal sepsis and hypoalbuminemia as well as poor surgical technique increase the risk of intestinal dehiscence, with considerable negative impact on patient morbidity and mortality. Live dog studies have demonstrated the dangers of mucosal eversion especially in the septic abdomen. Approximating patterns preserve luminal diameter, heal optimally, and have equal bursting strength compared with inverting patterns after 24 hours. Simple interrupted and simple continuous suture patterns and disposable skin staples are established alternatives for manual wound closure. Knotless quilled suture currently used in laparoscopic gastropexy techniques shows bursting strength equal to monofilament sutures in dog cadaveric intestine. Dehiscence rates with hand sewn vs titanium automated stapling anastomosis are similar in uncomplicated cases; however, auto stapling devices may be the preferred method of anastomosis when preexisting abdominal sepsis is present and when patient size allows it. Regardless of the technique, current standard of care involves leak testing and omental wrapping, followed by early postoperative feeding. The past decade has ushered in an exciting new era of laparoscopic assisted techniques that have the potential to reduce postoperative pain and patient morbidity. An understanding of these applications will establish the future of minimally invasive small animal intestinal surgery for veterinary specialists. In summary, surgeons have a variety of methods at their disposal for optimal clinical outcome in small animal intestinal surgery.

Ex vivo comparison of intradermal closures with conventional monofilament suture vs unidirectional barbed suture in dogs

OBJECTIVE

To evaluate the mechanical properties, strength, and quality of seal provided by continuous intradermal suture lines closed with barbed suture vs monofilament suture.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Forty-eight full-thickness wounds in canine cadavers.

METHODS

Four-centimeter-long parasagittal cutaneous wounds were created in canine cadavers. Each intradermal closure was closed with smooth monofilament suture and terminated with a 2 + 1 Aberdeen knot (n = 24) or a unidirectional barbed suture terminated with a single end pass (n = 24). Wounds (n = 12/group) were harvested, and a servohydraulic machine applied tensile load perpendicular to the long axis of the suture line. A load-displacement curve was generated; maximum load, displacement, stiffness, and mode of construct failure were recorded. Harvested wounds were placed in a watertight construct to measure the volume of fluid leaking over 3 minutes at 1.0 ± 0.1 psi.

RESULTS

Stiffness did not differ between constructs (P > .05). Incisions closed with monofilament sutures sustained higher maximum load (311.21 N ± 87.40) and displacement at failure (21.19 mm ± 4.51) compared with those with barbed sutures (116.38 N ± 42.82 and 15.03 mm ± 2.32, respectively, P < .05). Closures with monofilament sutures leaked more (4.38 mL ± 7.90) compared with those with barbed sutures (0.15 mL ± 0.43, P < .05).

CONCLUSION

Monofilament sutures resulted in stronger constructs, whereas barbed suture constructs provided a better watertight seal.

CLINICAL SIGNIFICANCE

While unidirectional barbed sutures may improve watertight skin closure, surgeons should consider using conventional monofilament sutures when mechanical strength of the closure is of primary concern.

Evaluation of suture reinforcement for stapled intestinal anastomoses: 77 dogs (2008-2018)

OBJECTIVE

To determine the influence of oversewing a transverse staple line in functional end-to-end stapled intestinal anastomoses (FEESA) in dogs.

STUDY DESIGN

Retrospective observational study.

SAMPLE POPULATION

Seventy-seven client-owned dogs that underwent 78 FEESA reinforced (n = 30) or not reinforced (n = 48) with suture at the transverse staple line.

METHODS

The medical records database was searched and reviewed for dogs that had undergone a FEESA between January 2008 and September 2018. Data were collected regarding signalment, body weight, clinical presentation, indication for surgery, serum albumin, presence of septic peritonitis, previous surgeries, surgical techniques (ie, oversew, crotch suture, omental wrap, omental patch, serosal patch), histopathology results, and postoperative outcome.

RESULTS

The only differences identified between groups consisted of higher preoperative albumin (2.89 ± 0.56 vs 2.34 ± 0.62 g/dL; P = .006) and lower postoperative dehiscence rate (0/30 vs 7/48; P = .028) in dogs with an oversewn FEESA. Oversewing the FEESA was identified as the significant factor in a model with oversewing and preoperative albumin fit to the outcome of dehiscence (oversew P = .010, albumin P = .761). The location of the dehiscence was specified in four of seven dogs, all along the transverse staple line. Patterns used for oversew were unspecified (n = 11), simple continuous (8), Cushing (4), simple interrupted (2), cruciate (1), interrupted horizontal mattress (1), and Lembert (1).

CONCLUSION

Oversewing the transverse staple line in FEESA was associated with a reduced occurrence of postoperative dehiscence.

CLINICAL SIGNIFICANCE

Our results provide evidence to support additional investigation of suture reinforcement (oversewing) at the transverse staple line of FEESA to reduce postoperative dehiscence.