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  • Author or Editor: Clarence A. Rawlings x
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Abstract

Objective—To develop laparoscopic-assisted techniques for enterostomy feeding tube placement and full-thickness biopsy of the jejunum in dogs.

Animals—15 healthy dogs.

Procedure—Dogs were anesthetized, and positive pressure ventilation was provided. A trocar cannula for the laparoscope was inserted on the ventral midline caudal to the umbilicus. For enterostomy tube placement, a second trocar cannula was placed lateral to the right rectus abdominis muscle, and a Babcock forceps was used to grasp the duodenum and elevate it to the incision made for the cannula. The duodenum was sutured to the abdominal wall, and a feeding tube was inserted. For jejunal biopsy, a third trocar cannula was placed lateral to the left rectus abdominis muscle. A portion of jejunum was elevated to the incision for the second or third cannula, and a full-thickness biopsy specimen was obtained. A second specimen was obtained from another portion of jejunum, and retention sutures for the 2 biopsy sites were tied so that serosal surfaces of the biopsy sites were apposed to each other. Dogs were euthanatized 30 days after surgery.

Results—The enterostomy tube was properly positioned and functional in all 8 dogs that underwent laparoscopic-assisted enterostomy tube placement, and sufficient samples for histologic examination were obtained from all 7 dogs that underwent laparoscopic-assisted jejunal biopsy. None of the dogs had any identifiable problems after surgery.

Conclusion and Clinical Relevance—Results suggest that in dogs, laparoscopic-assisted procedures for enterostomy tube placement and jejunal biopsy are an acceptable alternative to procedures performed during a laparotomy. (Am J Vet Res 2002; 63:1313–1319)

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in American Journal of Veterinary Research

Abstract

Objective—To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles.

Animals—12 adult female Beagles.

Procedure—During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery.

Results—Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%.

Conclusions and Clinical Relevance—Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of incontinence. (Am J Vet Res 2000;61:1353–1357)

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in American Journal of Veterinary Research

Abstract

Objective—To compare effects of medetomidine and xylazine hydrochloride on results of cystometry and micturition reflexes in healthy dogs and results of urethral pressure profilometry (UPP) in sedated and conscious dogs.

Animals—20 dogs.

Procedures—Urodynamic testing was performed 6 times in each dog (3 times after administration of xylazine [1 mg/kg of body weight, IV] and 3 times after administration of medetomidine (30 µg/kg, IM). Before each episode of sedation, UPP was performed. Heart and respiratory rates and indirect blood pressures were recorded prior to and 5, 10, 20, and 30 minutes after injection of sedative. Cystometry measurements included threshold volume, threshold pressure, and tonus limb. The UPP measurements included maximal urethral closure pressure (MUCP), functional profile length, and, in male dogs, plateau pressure.

Results—Mean MUCP was decreased markedly in xylazine- and medetomidine-sedated dogs. Xylazine and medetomidine also decreased plateau pressure in male dogs. The MUCP measurements were consistent among days for conscious and xylazine-sedated dogs but were inconsistent for medetomidinesedated female dogs. The proportion of valid cystometry measurements was greater for xylazine (39 of 60) than for medetomidine (27 of 60). Cystometry was considered invalid when bladder pressure reached 30 cm H2O without initiation of a micturition reflex.

Conclusions and Clinical Relevance—Medetomi dine and xylazine have similar effects on measurement of UPP and cystometry. Medetomidine was less consistent among days for UPP in female dogs and produced fewer valid cystometry tests, compared with xylazine. For urodynamic evaluations, medetomidine administered IM cannot be substituted for xylazine administered IV. (Am J Vet Res 2001;62:167–170)

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in American Journal of Veterinary Research

Abstract

Objective—To develop a model of low urethral pressure incontinence and compare the relative contributions of the pudendal and hypogastric nerves with urethral function by performing selective neurectomy and ovariohysterectomy in dogs.

Animals—19 healthy Foxhounds.

Procedure—Dogs were allocated into 2 groups. The first group (10 dogs) underwent bilateral hypogastric neurectomy and ovariohysterectomy and subsequent bilateral pudendal neurectomy. The second group (9 dogs) underwent bilateral pudendal neurectomy and subsequent hypogastric neurectomy and ovariohysterectomy. Urethral pressure profilometry and leak point pressure (LPP) tests were performed before and after each neurectomy.

Results—Before surgery, mean ± SD LPP and maximal urethral closure pressure (MUCP) in all dogs were 169.3 ± 24.9 cm H2O and 108.3 ± 19.3 cm H2O, respectively; these values decreased to 92.3 ± 27 cm H2O and 60.7 ± 20.0 cm H2O, respectively, after both selective neurectomy surgeries. There was a progressive decline of LPP after each neurectomy; however, MUCP decreased only after pudendal neurectomy. Fifteen dogs had mild clinical signs of urinary incontinence. All dogs appeared to have normal bladder function as indicated by posturing to void and consciously voiding a full stream of urine. Urinary tract infection did not develop in any dog.

Conclusions and Clinical Relevance—Hypogastric and pudendal neurectomy and ovariohysterectomy caused a maximum decrease in LPP, whereas pudendal neurectomy caused a maximum decrease in MUCP.

Impact on Human Medicine—This model may be useful for evaluation of treatments for improving urinary control in postmenopausal women. (Am J Vet Res 2005;66:695–699)

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in American Journal of Veterinary Research

Abstract

Objective—To develop a technique for laparoscopic gastropexy in dogs and evaluate effects on stomach position and strength of the adhesion between the stomach and abdominal wall.

Animals—8 healthy dogs.

Procedure—Dogs were anesthetized, and the abdomen was insufflated with carbon dioxide. A laparoscope was placed through a cannula inserted on the abdominal midline caudal to the umbilicus. Babcock forceps placed through a cannula inserted lateral to the right margin of the rectus abdominus muscle were used to exteriorize the pyloric antrum, a longitudinal incision was made through the serosa and muscular layer of the pyloric antrum, and the seromuscular layer of the pyloric antrum was sutured to the transversus abdominus muscle. After surgery, positive-contrast gastrography was used to evaluate stomach position and the onset of gastric emptying, and ultrasonography was used to assess stomach wall activity and mobility. Dogs were euthanatized 1 month after surgery, and tensile strength of the adhesion was tested.

Results—In all dogs, stomach position and the onset of gastric emptying were normal 25 days after surgery, and the pyloric antrum was firmly attached to the abdominal wall 30 days after surgery. Mean ± SD ultimate load of the adhesion in tension was 106.5 ± 45.6 N.

Conclusions and Clinical Relevance—The laparoscopic gastropexy technique described in the present study could be performed quickly and easily by an experienced surgeon, resulted in a strong fibrous adhesion between the stomach and abdominal wall, and appeared to cause minimal stress to the dogs. (Am J Vet Res 2001;62:871–875)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To develop a laparoscopic-assisted technique for cystopexy in dogs.

Animals—8 healthy male dogs, 7 healthy female dogs, and 3 client-owned dogs with retroflexion of the urinary bladder secondary to perineal herniation.

Procedure—Dogs were anesthetized, and positive pressure ventilation was provided. In the healthy male dogs, the serosal surface of the bladder was sutured to the abdominal wall. In the healthy female dogs, the serosa and muscular layer of the bladder were incised and sutured to the aponeurosis of the external and internal abdominal oblique muscles. Dogs were monitored daily for 30 days after surgery.

Results—All dogs recovered rapidly after surgery and voided normally. In the female dogs, results of urodynamic (leak point pressure and urethral pressure profilometry) and contrast radiographic studies performed 30 days after surgery were similar to results obtained before surgery. Cystopexy was successful in all 3 client-owned dogs, but 1 of these dogs was subsequently euthanatized because of leakage from a colopexy performed at the same time as the cystopexy.

Conclusion and Clinical Relevance—The laparoscopic-assisted cystopexy technique was quick, easy to perform, and not associated with urinary tract infection or abnormalities of urination. (Am J Vet Res 2002;63:1226–1231).

Full access
in American Journal of Veterinary Research