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.

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.

Minimally invasive repair of acetabular fractures in dogs: Ex vivo feasibility study and case report.

OBJECTIVE: To describe and evaluate minimally invasive repair of acetabular fractures in dogs using plates contoured to 3D-printed hemipelvic models. STUDY DESIGN: Ex vivo feasibility study and case report. SAMPLE POPULATION: Adult canine cadavers (n = 5); 8 year old male neutered Chihuahua. METHODS: Bone plates were contoured to 3D printed hemipelvic models derived from computed tomographic scans of each dog. In cadavers, acetabular, ischial, and pubic osteotomies were performed. A small craniolateral approach to the ilial body and a caudal approach to the ischium were made and connected through epiperiosteal tunnels. Under fluoroscopic guidance, fractures were reduced, and precontoured bone plates were applied with locking screws. Postoperative computed tomographic images were used to assess fracture gaps, step defects, and pelvic angulation. Cadavers were dissected for subjective assessment of sciatic nerve injury. Radiographic and clinical follow up was acquired for the clinical case. RESULTS: Small fracture gaps (<2 mm) and step defects (<1 mm), low pelvic angulation (<5°), and minimal (none n = 4 and mild n = 1) sciatic nerve injuries were observed in cadaver testing. There was slight (~1 mm) medial displacement of the pubic segment and good functional outcome for the clinical case, with radiographic healing documented at 3 months postoperatively. CONCLUSION: Minimally invasive acetabular fracture repair in dogs with the aid of 3D printing was feasible and accurate. CLINICAL SIGNIFICANCE: Minimally invasive repair techniques assisted by 3D printing may be applicable for acetabular fractures in dogs. The technique should be evaluated further before routine use can be recommended.

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.

Cette étude expérimentale a comparé les pressions de fuite et le temps de complétion d'anastomoses intestinales réalisées par des vétérinaires novices et un chirurgien certifié comme spécialiste en utilisant des schémas de suture simples interrompus et continus simples. Des segments jéjunaux grossièrement normaux (n = 108) de six cadavres canins frais ont été utilisés pour prélever des segments jéjunaux cadavériques canins refroidis de 8 cm qui ont été assignés au hasard à un groupe témoin (12 segments) et à quatre groupes de traitement (24 segments/groupe, 12 constructions/groupe) : i) anastomoses simples interrompues réalisées par un chirurgien agréé par le Board (BSI); ii) des anastomoses continues simples réalisées par un chirurgien certifié par le Board (BSC); iii) les anastomoses simples interrompues réalisées par des vétérinaires novices (NSI); et iv) des anastomoses continues simples réalisées par des vétérinaires novices (NSC). La pression de fuite initiale médiane (plage) pour le témoin était de 400,2 mmHg (226,0 à 500,0 mmHg), BSI 37,4 (14,4 à 124,0), BSC 32,5 (13,4 à 91,0), NSI 36,5 (22,9 à 62,0) et NSC 47,5 (8,9 à 120,0). Aucune différence n'a été notée entre l'expérience (P = 0,73, P = 0,53), la technique de suture (P = 0,07, P = 0,38) ou entre les groupes de traitement (P = 0,17, P = 0,94), pour l'ILP ou la MIP (pression intraluminale maximale), respectivement. Le temps de complétion de l'assemblage différait en fonction de la technique de suture (P < 0,0001) et de l'expérience (P < 0,0001). L'ILP médian et moyen de toutes les anastomoses dépassait les pressions péristaltiques intraluminales physiologiques. Les anastomoses continues simples étaient globalement plus rapides à réaliser. Les deux techniques d'anastomose cousues à la main conviennent aux anastomoses intestinales.(Traduit par Docteur Serge Messier).

Efficacy of ethylene oxide-sterilized waterproof cases for handheld cameras as sterile barriers for intraoperative imaging and recording.

OBJECTIVE: To evaluate the efficacy of ethylene oxide (EtOH) sterilization of 4 different waterproof camera cases and the ability of those sterilized cases to maintain a sterile barrier for intraoperative camera use. SAMPLE: 3 action cameras, 1 smartphone, and associated waterproof cases. PROCEDURES: Cases were inoculated by immersion in medium containing Staphylococcus pseudintermedius, Escherichia coli, and Pseudomonas aeruginosa and then manually cleaned and subjected to EtOH sterilization. Cameras were disinfected, loaded into sterile cases, and sterilely operated for 2 hours. Samples were collected from cases after inoculation, EtOH sterilization, camera loading, and 1 and 2 hours of operation and from all cameras after 2 hours of operation. Procedures were repeated twice, followed by an additional challenge round wherein cameras were purposefully contaminated prior to loading. All samples underwent bacterial culture. RESULTS: All cases were successfully sterilized, and loading of nonsterile cameras into sterile cases caused no contamination when cameras had been disinfected beforehand. Nonpathogenic environmental contaminants were recovered from 6 of 64 culture samples and 2 of 4 room samples. During the challenge round, only the postload sample for 1 case yielded E coli, suggesting sterile glove contamination; however, postload, 1-hour, and 2-hour samples for the GoPro case yielded E coli and S pseudintermedius, suggesting major contamination. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the evaluated cases can be safely sterilized with EtOH and used for image acquisition by aseptically prepared surgeons when cameras are disinfected prior to loading. Except for the GoPro camera, camera use did not jeopardize sterile integrity.

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.

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.

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.

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.

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.

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.