Evaluation of urethral orifice cross-section dimensions following perineal urethrostomy in male cats

OBJECTIVES

The aims of this study were: (1) To evaluate the urethral orifice cross-section size immediately and 12 days post-operatively following a perineal urethrostomy procedure. (2) To assess the correlation between the cross-section size and stricture formation during a 6-month period following the perineal urethrostomy.

ANIMALS

Twenty-four male cats with feline lower urinary tract disease that failed to respond to medical treatment and underwent perineal urethrostomy.

MATERIALS AND METHODS

The urethral orifice cross-section size was estimated by the largest size of the urinary catheter that was possible to insert facilely through the urethrostomy site. The urethral orifice cross-section size was measured in three different times: Pre-operative (LUCpr), immediately post-operative (LUCi) and 12 days post-operative (LUCp). Urinary obstruction recurrence and urethrostomy site stricture formation were documented for 6 months after the surgical procedure. The probabilities for obstruction recurrence in cases of LUCi ≤ 8Fr and LUCi > 8Fr were calculated.

RESULTS

Urinary obstruction and urethrostomy site stricture occurred in 5 of 24 (~20%) of the operated cats at an average of 92 ± 25 days post-perineal urethrostomy. LUCi ranged from 6 to 10 (median 10) Fr and the LUCp ranged from 4 to 10 (median 8) Fr. There was a significant decrease of 0.15 ± 0.09 mm² of the urethral orifice cross-section area 12 days post-operative compared to the measurements taken immediately post-operative. The probabilities for post-operative urinary obstruction of the LUCi ≤ 8Fr cases (intra-operative urethral orifice cross-section area equal or larger than 5.5 mm² ) and in the LUCi > 8Fr cases were 44 and 6%, respectively. Recurrence of obstruction was documented in all cases (three cats) in which LUCi was 6Fr.

CONCLUSION AND CLINICAL SIGNIFICANCE

The largest size of the urinary catheter that is possible to insert during surgery is a simple method to evaluate urethrostomy cross-section size. Contraction of the urethral orifice diameter is expected during the wound healing phase. Post-operative urinary obstruction is more likely in cases where LUCi < 8Fr.

Evaluation of crural release and ischial osteotomy for relief of tension in the repair of large segmental urethral defects in male cats

OBJECTIVE

To examine if the tension at the site of a urethral anastomosis can be relieved by performing either a crural release technique or an ischial osteotomy technique.

STUDY DESIGN

Cadaveric study and 2 case reports.

ANIMALS

Adult male cat cadavers (n = 18).

METHODS

Cats were divided into 2 groups; crural release (n = 9) and ischial osteotomy (n = 9). In each group, 20%, 25%, and 30% of the pelvic urethra was excised in 3 cats. The length of the urethral defect was measured after excision of the urethral segment, and after approximation, before and subsequent to the tension relieving technique performed. Two clinical cases are described.

RESULTS

Both crural release and ischial osteotomy were effective in relieving the tension encountered at the urethral anastomosis after removal of 20% of the urethral length. In the ischial osteotomy group, apposition without tension after removing up to 30% of the intrapelvic urethral length was easily achieved. A similar technique was successfully used in 2 clinical cases.

CONCLUSION

Crural release and ischial osteotomy techniques allow approximation and tension free anastomosis of large segmental defects of the pelvic urethra in cats.

Successful treatment of an intra-pelvic fungal pseudomycetoma causing constipation and hypercalcaemia in a Persian cat

This case report describes the successful treatment of a Persian cat diagnosed with intra-abdominal fungal pseudomycetoma causing hypercalcaemia and constipation due to an extra-luminal mechanical obstruction of the colon. Treatment included surgical excision, supportive care and itraconazole for 6 months.

Intrathoracic pseudocyst in a kitten

A 2-month-old, intact, female domestic shorthair kitten presented with a history of acute-onset dyspnoea. Severe dyspnoea and tachypnoea were noted on physical examination. Serosanguinous fluid, consistent with a modified transudate, was aspirated from the pleural cavity immediately after the physical examination, with an immediate decrease in respiratory rate and effort. The thorax was radiographed and the entire left hemithorax appeared to be filled with a large soft tissue density mass. Thoracic ultrasound was performed and a cystic structure, measuring 3.0 cm × 1.5 cm, was seen in the left hemithorax. An explorative thoracotomy was performed and a mass obliterating the left hemithorax was found. The mass was removed by a combination of blunt and sharp dissection. A final diagnosis of thoracic pseudocyst was made on histological examination of the tissue. The mass was described as a sterile process characteristic of an organised seroma or haematoma. Recovery from surgery was uneventful and the kitten was discharged 48 h postoperatively. The kitten was still alive with no recurrence of clinical signs at the time of writing this report, 8 months postoperatively.