Penile urethral resection and anastomosis augmentation with regional tissue tension relieving technique: A cadaveric mechanical study and clinical outcome in two dogs

Ex vivo biomechanical evaluation of tissue construct strength in an equine colopexy model

OBJECTIVE

To compare strength of left paramedian colopexies using various techniques in equine ex vivo models.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Equine cadavers euthanized for nongastrointestinal pathology (36 specimens derived from 9 horses).

METHODS

Colopexies were performed after euthanasia. Suture pattern (horizontal mattress vs. cruciate) and incorporation of dorsal sheath of the rectus abdominis (partial-thickness) versus incorporation of dorsal and ventral sheath of the rectus abdominis (full-thickness) were evaluated. Single cycle load to failure, work to peak load, stiffness, and mode of failure of colopexy tissue constructs were assessed.

RESULTS

Mean load to failure of all constructs ranged from 102.26 to 166.38 N. Partial-thickness bites demonstrated a mean load to failure and standard deviation (SD) of 111.91 (35.88) N and 102.26 (30.06) N (p < .05) which was significantly lower than the mean and SD of full-thickness bites (166.3 [72.42] N and 163.21 [51.40 N]), respectively. All full-thickness bites regardless of suture pattern and over half of partial-thickness bites failed at the colonic wall. There was no significant difference in load to failure compared to mode of failure.

CONCLUSION

A stronger colopexy was achieved with a full-thickness bite regardless of the suture pattern. The most common mode of failure was the colon wall.

CLINICAL SIGNIFICANCE

Incorporating ventral and dorsal fascia of the rectus abdominus provided a stronger colopexy structure, which may necessitate a second incision or subcutaneous palpation of the needle when performing a colopexy. The lateral band of the colon failed in most constructs (77%) regardless of technique, which could weaken the colonic wall and risk colonic rupture.

Preputial urethrostomy with preservation of the local anatomy in 4 dogs

OBJECTIVE

To describe a novel modified preputial urethrostomy with preservation of the local anatomy in 4 dogs.

STUDY DESIGN

Short case series.

ANIMALS

Four client-owned male dogs.

METHODS

Dogs presented for dysuria and urethral obstruction and underwent a modified preputial urethrostomy as a salvage procedure after the failure of previous treatments. Urethral stenosis or tear was confirmed by cysto-urethrography in all dogs. The preputial urethrostomy involved anastomosis of the pelvic urethra with the preputial mucosa after caudal laparotomy, without dissection of the prepuce or amputation of the penis. Owner follow up was obtained by telephone interview.

RESULTS

Urinary obstruction was due to urethral stenosis in 3 dogs and severe complications following perineal urethrostomy in 1 dog. The urinary obstruction was resolved in all dogs by the modified preputial urethrostomy. None of the dogs had signs of dysuria, urinary tract infection, or dermatitis immediately postoperatively. Two dogs showed signs of urinary incontinence from 15 days to 1 month postoperatively, which persisted throughout the follow-up period.

CONCLUSION

A functional urethral stoma was obtained in all dogs. This technique may be an alternative to prepubic urethrostomy in male dogs.