Urethral obstruction

Danièlle Gunn-Moore

doi:10.22233/9781910443149.4.11

British Small Animal Veterinary Association , 152 (2013); https://doi.org/10.22233/9781910443149.4.11

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Urethral obstruction

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Author: Danièlle Gunn-Moore
From: BSAVA Manual of Feline Practice
Item: Chapter 4.11, pp 152 - 160
DOI: 10.22233/9781910443149.4.11
Copyright: © 2013 British Small Animal Veterinary Association
Publication Date: January 2013

Abstract

Urethral obstruction can be caused by feline idiopathic cystitis (FIC), spasm, urethral plugs, stones, neoplasia or strictures. Affected cats usually have a history of stranguria, dysuria, pollakiuria, and/or haematuria. This chapter considers clinical signs, diagnosis, initial assessment and therapy, relieving the obstruction, catheter choice, aftercare, unsuccessful catheterization and relief without catheterization. Quick reference guides: Approach to hyperkalaemia; Relief of urethral obstruction in a tomcat; Urinalysis; Cystocentesis.

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4.11.1

(a) Some catheter options (bottom to top): Standard (Jackson-type) tomcat catheter (red hub) – stiff, with a metal stylet, rough side holes and therefore traumatic; Slippery Sam (white hub, grey catheter) – end hole or side holes, atraumatic and stiff, so good for initial unblocking; open-ended tomcat catheter (white hub, longer catheter) – end hole, atraumatic and stiff, good for initial unblocking; Mila EZGO (clear hub, blue securing wings attached) – end hole and atraumatic, but quite soft and can be difficult to place – ideal for leaving in situ. Unattached securing wings for use with the Mila catheter and a ‘Little Herbert’ Luer lock adapter (navy blue) which can be attached to the end of these catheters to make them easier to attach to a closed urine collection system are also shown. (b) Catheter tips (left to right): Jackson-type with stylet visible; Slippery Sam; open-ended tomcat catheter; Mila EZGO. © 2013 British Small Animal Veterinary Association

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4.11.1 (a) Some catheter options (bottom to top): Standard (Jackson-type) tomcat catheter (red hub) – stiff, with a metal stylet, rough side holes and therefore traumatic; Slippery Sam (white hub, grey catheter) – end hole or side holes, atraumatic and stiff, so good for initial unblocking; open-ended tomcat catheter (white hub, longer catheter) – end hole, atraumatic and stiff, good for initial unblocking; Mila EZGO (clear hub, blue securing wings attached) – end hole and atraumatic, but quite soft and can be difficult to place – ideal for leaving in situ. Unattached securing wings for use with the Mila catheter and a ‘Little Herbert’ Luer lock adapter (navy blue) which can be attached to the end of these catheters to make them easier to attach to a closed urine collection system are also shown. (b) Catheter tips (left to right): Jackson-type with stylet visible; Slippery Sam; open-ended tomcat catheter; Mila EZGO.

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4.11.2

(a) A pigtail catheter. Pigtail catheters contain a stylet to allow insertion directly through the body and bladder wall. After placement the stylet is removed. There is a locking loop (a small string) that is then pulled to lock and secure the pigtail loop within the bladder. (b) Urine has been aspirated into this syringe, which is attached to the end of a pigtail catheter which has been inserted into the bladder; the urine confirms the catheter’s placement in the bladder. Pulling the locking loop as shown secures the pigtail loop in the bladder. This cat had a urethral rupture due to a road traffic accident, and the pigtail catheter allowed urinary diversion. (c) This lateral abdominal radiograph shows the pigtail catheter with its end in the bladder. The bladder contains some positive contrast material but there is moderate loss of serosal detail in the caudal abdomen due to uroabdomen. Additionally a urethral catheter is seen caudally, superimposed over the thighs and bladder neck and ending at the level of the ventral aspect of L7, thus not following a normal urethral path due to the urethral rupture which was confirmed by a positive contrast urethrogram (not shown here). Staples are present due to a previous laparotomy. (Courtesy of The Feline Centre, Langford Veterinary Services, University of Bristol). © 2013 British Small Animal Veterinary Association

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4.11.2 (a) A pigtail catheter. Pigtail catheters contain a stylet to allow insertion directly through the body and bladder wall. After placement the stylet is removed. There is a locking loop (a small string) that is then pulled to lock and secure the pigtail loop within the bladder. (b) Urine has been aspirated into this syringe, which is attached to the end of a pigtail catheter which has been inserted into the bladder; the urine confirms the catheter’s placement in the bladder. Pulling the locking loop as shown secures the pigtail loop in the bladder. This cat had a urethral rupture due to a road traffic accident, and the pigtail catheter allowed urinary diversion. (c) This lateral abdominal radiograph shows the pigtail catheter with its end in the bladder. The bladder contains some positive contrast material but there is moderate loss of serosal detail in the caudal abdomen due to uroabdomen. Additionally a urethral catheter is seen caudally, superimposed over the thighs and bladder neck and ending at the level of the ventral aspect of L7, thus not following a normal urethral path due to the urethral rupture which was confirmed by a positive contrast urethrogram (not shown here). Staples are present due to a previous laparotomy. (Courtesy of The Feline Centre, Langford Veterinary Services, University of Bristol).

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Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

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Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission. Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

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Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

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Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission. Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

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Leucocytes (L) in sediment: KovaStain; original magnification X400. At this magnification, leucocytes take up sediment stains to give a lightly granular appearance in a rounded outline. Leucocytes are around 2–2.5 times the size of erythrocytes. The background cells, which are out of focus, are a mixture of leucocytes and erythrocytes but full identification is not possible without focusing.

Leucocytes (L) in sediment: KovaStain; original magnification X400. At this magnification, leucocytes take up sediment stains to give a lightly granular appearance in a rounded outline. Leucocytes are around 2–2.5 times the size of erythrocytes. The background cells, which are out of focus, are a mixture of leucocytes and erythrocytes but full identification is not possible without focusing. © 2013 British Small Animal Veterinary Association

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Leucocytes (L) in sediment: KovaStain; original magnification X400. At this magnification, leucocytes take up sediment stains to give a lightly granular appearance in a rounded outline. Leucocytes are around 2–2.5 times the size of erythrocytes. The background cells, which are out of focus, are a mixture of leucocytes and erythrocytes but full identification is not possible without focusing. Leucocytes (L) in sediment: KovaStain; original magnification X400. At this magnification, leucocytes take up sediment stains to give a lightly granular appearance in a rounded outline. Leucocytes are around 2–2.5 times the size of erythrocytes. The background cells, which are out of focus, are a mixture of leucocytes and erythrocytes but full identification is not possible without focusing.

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Transitional epithelial cell (T) in sediment: KovaStain; original magnification X400. These cells are larger than neutrophils and have a granular appearance with most sediment stains. They may occur singly, as here, or in aggregates or sheets. The degree of nuclear detail with sediment stain is inadequate to assess criteria of malignancy – a cytology preparation from urine collected into EDTA is required.

Transitional epithelial cell (T) in sediment: KovaStain; original magnification X400. These cells are larger than neutrophils and have a granular appearance with most sediment stains. They may occur singly, as here, or in aggregates or sheets. The degree of nuclear detail with sediment stain is inadequate to assess criteria of malignancy – a cytology preparation from urine collected into EDTA is required. © 2013 British Small Animal Veterinary Association

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Transitional epithelial cell (T) in sediment: KovaStain; original magnification X400. These cells are larger than neutrophils and have a granular appearance with most sediment stains. They may occur singly, as here, or in aggregates or sheets. The degree of nuclear detail with sediment stain is inadequate to assess criteria of malignancy – a cytology preparation from urine collected into EDTA is required. Transitional epithelial cell (T) in sediment: KovaStain; original magnification X400. These cells are larger than neutrophils and have a granular appearance with most sediment stains. They may occur singly, as here, or in aggregates or sheets. The degree of nuclear detail with sediment stain is inadequate to assess criteria of malignancy – a cytology preparation from urine collected into EDTA is required.

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Squamous epithelial cell in sediment: KovaStain; original magnification X400. These are seen frequently in free-catch samples and are either from the distal urethra or the external skin. These large cells are often angular, and small nuclei may be noted.

Squamous epithelial cell in sediment: KovaStain; original magnification X400. These are seen frequently in free-catch samples and are either from the distal urethra or the external skin. These large cells are often angular, and small nuclei may be noted. © 2013 British Small Animal Veterinary Association

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Squamous epithelial cell in sediment: KovaStain; original magnification X400. These are seen frequently in free-catch samples and are either from the distal urethra or the external skin. These large cells are often angular, and small nuclei may be noted. Squamous epithelial cell in sediment: KovaStain; original magnification X400. These are seen frequently in free-catch samples and are either from the distal urethra or the external skin. These large cells are often angular, and small nuclei may be noted.

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Coarse granular casts in sediment: KovaStain; original magnification X400. These casts are proteinaceous and have a stippled, grainy appearance to their interior structure. While low levels are unremarkable, higher numbers may be associated with an insult (e.g. toxic, hypoxic) to renal tubules. No numerical values exist to define what constitutes low, medium and high numbers of casts; this is a subjective assessment.

Coarse granular casts in sediment: KovaStain; original magnification X400. These casts are proteinaceous and have a stippled, grainy appearance to their interior structure. While low levels are unremarkable, higher numbers may be associated with an insult (e.g. toxic, hypoxic) to renal tubules. No numerical values exist to define what constitutes low, medium and high numbers of casts; this is a subjective assessment. © 2013 British Small Animal Veterinary Association

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Coarse granular casts in sediment: KovaStain; original magnification X400. These casts are proteinaceous and have a stippled, grainy appearance to their interior structure. While low levels are unremarkable, higher numbers may be associated with an insult (e.g. toxic, hypoxic) to renal tubules. No numerical values exist to define what constitutes low, medium and high numbers of casts; this is a subjective assessment. Coarse granular casts in sediment: KovaStain; original magnification X400. These casts are proteinaceous and have a stippled, grainy appearance to their interior structure. While low levels are unremarkable, higher numbers may be associated with an insult (e.g. toxic, hypoxic) to renal tubules. No numerical values exist to define what constitutes low, medium and high numbers of casts; this is a subjective assessment.

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Struvite (magnesium ammonium phosphate or ‘triple phosphate’) crystals in sediment: KovaStain; original magnification X400. These elongated crystals may vary in size but are recognizable by their ‘coffin lid’ structure.

Struvite (magnesium ammonium phosphate or ‘triple phosphate’) crystals in sediment: KovaStain; original magnification X400. These elongated crystals may vary in size but are recognizable by their ‘coffin lid’ structure. © 2013 British Small Animal Veterinary Association

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Struvite (magnesium ammonium phosphate or ‘triple phosphate’) crystals in sediment: KovaStain; original magnification X400. These elongated crystals may vary in size but are recognizable by their ‘coffin lid’ structure. Struvite (magnesium ammonium phosphate or ‘triple phosphate’) crystals in sediment: KovaStain; original magnification X400. These elongated crystals may vary in size but are recognizable by their ‘coffin lid’ structure.

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Calcium oxalate dihydrate crystals in sediment: KovaStain; original magnification X400. Square crystals with lines intersecting from the corners are the most frequent form, but aggregates may occur to give a more complex shape.

Calcium oxalate dihydrate crystals in sediment: KovaStain; original magnification X400. Square crystals with lines intersecting from the corners are the most frequent form, but aggregates may occur to give a more complex shape. © 2013 British Small Animal Veterinary Association

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Calcium oxalate dihydrate crystals in sediment: KovaStain; original magnification X400. Square crystals with lines intersecting from the corners are the most frequent form, but aggregates may occur to give a more complex shape. Calcium oxalate dihydrate crystals in sediment: KovaStain; original magnification X400. Square crystals with lines intersecting from the corners are the most frequent form, but aggregates may occur to give a more complex shape.

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Calcium oxalate monohydrate crystals in sediment: KovaStain; original magnification X400. There are different forms of calcium oxalate monohydrate; the most common flat hexagonal form is illustrated here. There are also small slightly elongated ovoid shapes and ‘bow tie’ forms.

Calcium oxalate monohydrate crystals in sediment: KovaStain; original magnification X400. There are different forms of calcium oxalate monohydrate; the most common flat hexagonal form is illustrated here. There are also small slightly elongated ovoid shapes and ‘bow tie’ forms. © 2013 British Small Animal Veterinary Association

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Calcium oxalate monohydrate crystals in sediment: KovaStain; original magnification X400. There are different forms of calcium oxalate monohydrate; the most common flat hexagonal form is illustrated here. There are also small slightly elongated ovoid shapes and ‘bow tie’ forms. Calcium oxalate monohydrate crystals in sediment: KovaStain; original magnification X400. There are different forms of calcium oxalate monohydrate; the most common flat hexagonal form is illustrated here. There are also small slightly elongated ovoid shapes and ‘bow tie’ forms.

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Bilirubin crystals in sediment: KovaStain; original magnification X400. Bilirubin has a golden coloration and most usually forms thin, needle-like crystals which bunch together to form a structure resembling a bundle of twigs tied in the middle.

Bilirubin crystals in sediment: KovaStain; original magnification X400. Bilirubin has a golden coloration and most usually forms thin, needle-like crystals which bunch together to form a structure resembling a bundle of twigs tied in the middle. © 2013 British Small Animal Veterinary Association

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Bilirubin crystals in sediment: KovaStain; original magnification X400. Bilirubin has a golden coloration and most usually forms thin, needle-like crystals which bunch together to form a structure resembling a bundle of twigs tied in the middle. Bilirubin crystals in sediment: KovaStain; original magnification X400. Bilirubin has a golden coloration and most usually forms thin, needle-like crystals which bunch together to form a structure resembling a bundle of twigs tied in the middle.

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Lipid droplets in sediment: KovaStain; original magnification X400. Lipid droplets like these float above the plane of the rest of the sample and are always clear. They vary in size and have no internal structure.

Lipid droplets in sediment: KovaStain; original magnification X400. Lipid droplets like these float above the plane of the rest of the sample and are always clear. They vary in size and have no internal structure. © 2013 British Small Animal Veterinary Association

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Lipid droplets in sediment: KovaStain; original magnification X400. Lipid droplets like these float above the plane of the rest of the sample and are always clear. They vary in size and have no internal structure. Lipid droplets in sediment: KovaStain; original magnification X400. Lipid droplets like these float above the plane of the rest of the sample and are always clear. They vary in size and have no internal structure.

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Bacteria and leucocytes in a cytology preparation: modified Wright’s stain; original magnification X500. All the nucleated cells here are poorly preserved neutrophils. They are surrounded by very high numbers of a monomorphic population of bacteria. This would be compatible with the presence of a UTI if urine had been collected by cystocentesis.

Bacteria and leucocytes in a cytology preparation: modified Wright’s stain; original magnification X500. All the nucleated cells here are poorly preserved neutrophils. They are surrounded by very high numbers of a monomorphic population of bacteria. This would be compatible with the presence of a UTI if urine had been collected by cystocentesis. © 2013 British Small Animal Veterinary Association

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Bacteria and leucocytes in a cytology preparation: modified Wright’s stain; original magnification X500. All the nucleated cells here are poorly preserved neutrophils. They are surrounded by very high numbers of a monomorphic population of bacteria. This would be compatible with the presence of a UTI if urine had been collected by cystocentesis. Bacteria and leucocytes in a cytology preparation: modified Wright’s stain; original magnification X500. All the nucleated cells here are poorly preserved neutrophils. They are surrounded by very high numbers of a monomorphic population of bacteria. This would be compatible with the presence of a UTI if urine had been collected by cystocentesis.

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Clinician preference varies but usually the thumb is positioned at the cranial pole of the bladder, so that the bladder is immobilized caudal to the thumb, as shown here. Alternatively, you can position your thumb at the caudal extremity of the bladder, stabilizing it cranial to your thumb Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

Clinician preference varies but usually the thumb is positioned at the cranial pole of the bladder, so that the bladder is immobilized caudal to the thumb, as shown here. Alternatively, you can position your thumb at the caudal extremity of the bladder, stabilizing it cranial to your thumb Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission. © 2013 British Small Animal Veterinary Association

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Clinician preference varies but usually the thumb is positioned at the cranial pole of the bladder, so that the bladder is immobilized caudal to the thumb, as shown here. Alternatively, you can position your thumb at the caudal extremity of the bladder, stabilizing it cranial to your thumb Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission. Clinician preference varies but usually the thumb is positioned at the cranial pole of the bladder, so that the bladder is immobilized caudal to the thumb, as shown here. Alternatively, you can position your thumb at the caudal extremity of the bladder, stabilizing it cranial to your thumb Drawn by S.J. Elmhurst BA Hons (www.livingart.org.uk) and reproduced with her permission.

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Ultrasonography of the bladder, if available, can be used to direct cystocentesis. The needle can be seen entering the black anechoic urine within the bladder (arrowed).

Ultrasonography of the bladder, if available, can be used to direct cystocentesis. The needle can be seen entering the black anechoic urine within the bladder (arrowed). © 2013 British Small Animal Veterinary Association

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Ultrasonography of the bladder, if available, can be used to direct cystocentesis. The needle can be seen entering the black anechoic urine within the bladder (arrowed). Ultrasonography of the bladder, if available, can be used to direct cystocentesis. The needle can be seen entering the black anechoic urine within the bladder (arrowed).

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