Comparison of Laparoscopic and Open Cystopexy in a Cadaveric Canine Model

Feasibility of laparoscopic stapled partial cystectomy in canine cadavers

OBJECTIVE

To describe a technique for laparoscopic partial cystectomy and evaluate sealing of canine urinary bladder tissue with an endoscopic stapler.

STUDY DESIGN

Prospective, cadaveric study.

SAMPLE POPULATION

Eleven canine cadavers.

METHODS

Laparoscopic partial cystectomy was performed with an endoscopic gastrointestinal anastomosis (GIA) stapler. Leak testing and urodynamic evaluation was performed to measure intravesical pressure at initial leakage and catastrophic failure or the maximum pressure at which intravesical pressure plateaued. Surgical time, complications, and site of leakage were also recorded.

RESULTS

Laparoscopic partial cystectomy was successfully performed in 10 of 11 cadavers. Median procedure time was 13.6 min (10.1-15.2 min). Median intravesical pressure at initial leakage was 31 mmHg (28-56 mmHg) with a median increase from initial pressure of 15 mmHg (11-37 mmHg). No catastrophic failure of the cystectomy site was observed during leak testing. Intravesical pressure plateaued at a median of 52 mmHg (39-73 mmHg), which was a median of 13 mmHg (8-23 mmHg) higher than intravesical pressure at initial leakage. The median total volume infused at the time of plateau of intravesical pressure was 89 mL (58-133 mL).

CONCLUSION

Laparoscopic stapled partial cystectomy was feasible in canine cadavers. Endoscopic GIA staplers appear to seal the canine urinary bladder with minimal leakage.

CLINICAL SIGNIFICANCE

Use of an endoscopic GIA stapler may provide a minimally invasive option for partial cystectomy in dogs. Further evaluation for application to clinical cases is warranted.

Comparison of leakage pressures of vesicourethral anastomosis performed with intracorporeal suturing in a simulator and conventional suturing ex vivo in canine cadaveric tissue

OBJECTIVE

To compare conventional and intracorporeal vesicourethral anastomosis (VUA) in canine cadaveric tissue.

STUDY DESIGN

Cadaveric ex vivo study.

STUDY POPULATION

Twenty-eight canine bladders with urethra.

METHODS

Specimens after prostatectomy were randomly divided into intracorporeal (I) group or conventional (C) group. For the I group, VUA was performed in a simulator with laparoscopic needle holders and telescope. For the C group, the anastomosis was performed in vitro with standard instruments. The VUA was performed with 4-0 monofilament absorbable suture and was completed with two simple continuous sutures. Surgical time, leakage pressure, site of leakage, and number of suture bites were recorded.

RESULTS

Fourteen samples were entered in each group. The dorsal side of the anastomosis was initially performed, followed by the ventral side. The median suturing time was 30.8 minutes (range, 19.3-39.2) for the I group and 17.3 minutes (range, 9.2-21.3) for the C group (P < .0001). The median leakage pressure was 10.9 mm Hg (range, 4.1-29.7) for the I group and 10.8 mm Hg (range, 6.2-18.5) for the C group (P = .94). The median number of stitches was 20 (range, 14-26) for the I group and 19 (range, 11-28) for the C group (P = .96). The distribution of the site of leakage was similar between groups (P = .381).

CONCLUSION

Vesicourethral anastomosis can be performed with leakage pressures similar to intracorporeal and conventional suturing.

CLINICAL SIGNIFICANCE

This study represents the first step toward laparoscopic radical prostatectomy in dogs.

Feasibility of thoracoscopic attenuation of the azygos vein as a model for portoazygos shunts: A canine cadaveric study

OBJECTIVE

To evaluate the feasibility of thoracoscopic placement of three vascular attenuation devices by using the azygos vein as a model for portoazygos (PA) shunts and to describe the approach for thoracoscopic placement of these attenuation devices in small breed dogs.

STUDY DESIGN

Randomized, prospective, cadaveric study.

ANIMALS

Cadavers of 10 adult small breed dogs.

METHODS

Cadavers were placed in sternal recumbency with left dorsolateral obliquity, and three thoracoscopic ports were established in the right hemithorax at the mid-10th intercostal space and dorsal third of the ninth and 11th intercostal spaces. The caudal azygos vein was thoracoscopically isolated along three adjacent segments bordered by four intercostal arteries, beginning just cranial to the first intercostal artery visualized cranial to the diaphragm. Three attenuation devices including coated cellophane, uncoated cellophane, and a 5-mm ameroid constrictor were thoracoscopically placed around one segment in each dog. Minor port access modifications were required to improve working space and triangulation in three dogs. Ability to successfully place the device, time required for placement, endoscopic clip configuration, and complications associated with placement were recorded.

RESULTS

Median dog weight was 7.7 kg (range, 1.8-11). All attenuation devices were successfully placed thoracoscopically in all cadavers. No difference was detected in time required for placement between the ameroid constrictor and coated and uncoated cellophane (range, 2.3-33.8 minutes, P = .8).

CONCLUSION

Ameroid constrictors and thin film bands were consistently placed via thoracoscopy around the caudal azygos vein of small breed dogs.

CLINICAL SIGNIFICANCE

These results justify further investigation of thoracoscopic PA shunt attenuation in affected dogs.

Bidirectional knotless barbed versus conventional smooth suture for closure of surgical wounds in inguinal castration in horses

Background

Castration of the stallion is one of the most frequently performed surgical procedures in the horse. Recently barbed suture materials for surgical wound closure were introduced to the market with manufacturers claiming that these sutures enhance speed and security as they eliminate the need to tie knots. Recently, it has been suggested that this type of suture may increase postoperative complications. This study aimed at investigating and comparing a bidirectional absorbable knotless barbed suture (KBS) to a conventional smooth suture (SS) for wound closure of inguinal castrations in the horse. This was done by evaluating short-term and post-discharge complications and by comparing the time spent on suturing the surgical wounds after bilateral inguinal castration, which was performed on 45 horses undergoing castration at The Large Animal Teaching Hospital at University of Copenhagen from September 2017 to May 2019.

Results

Short-term complications were few; at 24 h minor swelling occurred in 29 and 33% of horses sutured with KBS and SS respectively and cutaneous dehiscence during recovery occurred in two horses of each group. Post-discharge follow-up revealed that three horses needed veterinary attention for treatment of complications (scrotal swelling (n = 1, KBS); wound exudation (n = 1, SS) and wound dehiscence after return to pasture (n = 1, SS)). Wound closure was achieved 6 min faster with KBS than with SS (P < 0.0001).

Conclusions

Use of the KBS suture did not result in increased occurrence of postoperative complications. Wound closure was faster with KBS than with SS in equine bilateral inguinal castration. Our results show that KBS can safely be used in the horse following bilateral inguinal castrations without adverse effects and with a reduction in suturing time.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model

OBJECTIVE

To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies.

STUDY DESIGN

Ex vivo, simple randomized study.

SAMPLE POPULATION

Urinary bladders harvested from canine cadavers (n = 23).

METHODS

Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies.

RESULTS

Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders.

CONCLUSION

Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure.

CLINICAL SIGNIFICANCE

This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Biomechanical analysis of unidirectional knotless suture loop weld integrity after passage through a cadaveric body wall

OBJECTIVE

To evaluate the integrity of the welded end loop on unidirectional knotless suture after transabdominal passage in a canine cadaver.

STUDY DESIGN

Ex vivo biomechanical study.

STUDY POPULATION

Four variations of unidirectional knotless suture and 1 canine cadaver.

METHODS

Welded end loop on strands consisted of 0 Quill polydioxanone (QP; n = 22), 0 Quill monoderm (QM; n = 23), 2-0 V-Loc 90 (V9; n = 12), and 2-0 V-Loc 180 (V18; n = 12). Half of the suture strands in each group were passed percutaneously through an insufflated cadaveric body wall, and the remaining half served as intact controls. A linear testing machine was used to load the sutures to failure. Modes of and loads to failure were compared within and between suture types.

RESULTS

Loads to failure did not differ between sutures passed through the body wall and their controls when the loop remained intact. Sutures V9, V18, and QM sustained higher loads to failure compared with QP. All Quill suture lines failed at the weld during testing. Thirty-three percent of QP sutures failed at the weld during initial passage through the body wall. V-Loc sutures failed at the suture-apparatus interface, within the welded loop, or a combination.

CONCLUSION

Passing suture through a cadaveric body wall did not affect the integrity of the welded end loop of any of the unidirectional knotless sutures tested here when the loop remained intact.

CLINICAL SIGNIFICANCE

Unidirectional knotless suture (V9, V18 and QM) can be safely passed through a canine body wall for use in laparoscopic procedures. The use of QP in this manner cannot be recommended.

Efficacy of vaporized hydrogen peroxide for repeated sterilization of a single-use single-incision laparoscopic surgery port

OBJECTIVE

To determine the ability of vaporized hydrogen peroxide (VHP) to sterilize a single-use single-incision laparoscopic surgery port and its associated components after repeated simulated uses.

STUDY DESIGN

Prospective in vitro experimental study.

SAMPLE POPULATION

Six single-use single-incision laparoscopic surgery ports with associated cannulas and insufflation tubing.

METHODS

Ports, cannulas, and tubing were subjected to 10 cycles of simulated use, bacterial inoculation with Staphylococcus pseudintermedius and Escherichia coli, decontamination and sterilization, and testing via culture based on their treatment group designation. Bacteriological scores were compared among the negative control, positive control, and 4 treated ports and components.

RESULTS

There was no difference in bacteriological scores between treated ports, cannulas, and insufflation tubing and the negative control port and components. Bacteriological scores of ports and components undergoing 6-10 cycles were not significantly different from scores of ports and components undergoing 5 or fewer sterilization cycles. No difference was found in detection of bacteria from treated ports by biopsy of the foam versus sampling via wash.

CONCLUSION

This study suggests that a single-use single-incision laparoscopic port and its associated components can be effectively sterilized after multiple simulated uses by using VHP.

CLINICAL SIGNIFICANCE

Reuse of a single-use single-incision laparoscopic port is a safe and effective method of cost reduction in veterinary patients.

Adherence of methicillin-resistant Staphylococcus pseudintermedius to suture materials commonly used in small animal surgery

OBJECTIVE

To evaluate adherence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to 5 suture materials commonly used in small animal surgery.

SAMPLE

10 epidemiologically unrelated MRSP isolates (obtained from dogs with clinical infections) that had strong biofilm-forming ability and 5 types of suture.

PROCEDURES

The 5 types of suture evaluated were monofilament polyglecaprone 25, monofilament polydioxanone, triclosan-coated (TC)-monofilament polydioxanone, braided polyglactin 910, and barbed monofilament polydioxanone. Suture segments were incubated in standard suspensions of MRSP for 2 minutes. Segments were then placed in tryptone soy broth and incubated overnight. After incubation, segments were rinsed with PBS solution and sonicated to dislodge adherent bacteria. Resulting suspensions were used to create serial dilutions that were plated, incubated overnight, and counted the following day. Bacterial adherence to 1 segment of each suture type was assessed by use of scanning electron microscopy.

RESULTS

There was significantly less adherence of MSRP to TC-monofilament polydioxanone than to polyglecaprone 25, polyglactin 910, barbed monofilament polydioxanone, and monofilament polydioxanone. There was significantly less adherence of MSRP to polyglecaprone than to polyglactin 910.

CONCLUSIONS AND CLINICAL RELEVANCE

Barbed suture had a bacterial adherence profile comparable to that for monofilament suture. Adherence of MRSP was greatest for braided polyglactin 910. Use of TC-monofilament polydioxanone can be considered for patients that are at high risk of developing surgical site infections and for which a surgeon chooses a multifilament suture.

Germline gene polymorphisms predisposing domestic mammals to carcinogenesis

Cancer is a complex disease caused in part by predisposing germline gene polymorphisms. Knowledge of carcinogenesis in companion mammals (dog and cat) and some livestock species (pig and horse) is quite advanced. The prevalence of certain cancers varies by breed in these species, suggesting the presence of predisposing genetic variants in susceptible breeds. This review summarizes the present understanding of germline gene polymorphisms, including BRCA1, BRCA2, MC1R, KIT, NRAS and RAD51, associated with predisposition to melanoma, mammary cancer, osteosarcoma and histiocytic sarcoma in dogs, cats, pigs and horses. The predisposing variants in these species are discussed in the context of human germline gene polymorphisms associated with the same types of cancer.