Prevalence and disease associations in feline thrombocytopenia: a retrospective study of 194 cases

OBJECTIVES

To assess the prevalence of thrombocytopenia in a referral population of cats in the UK, to identify disease processes associated with thrombocytopenia and to assess the proportion of thrombocytopenic cats that tested positive for feline leukaemia virus or feline immunodeficiency virus.

MATERIALS AND METHODS

Retrospective analysis of medical records at a UK referral hospital. Cats were grouped by mechanism of thrombocytopenia and disease process (where known).

RESULTS

Prevalence of thrombocytopenia was 5·9%. The most common disease processes associated with thrombocytopenia were haematological or infectious disease and neoplasia; 11% of thrombocytopenic cats tested were positive for feline leukaemia virus, which is lower than reported previously. Cats presenting with unexplained haemorrhage had significantly lower platelet counts than other thrombocytopenic cats. Primary immune-mediated thrombocytopenia was less commonly diagnosed than in dogs and associated with the most severe platelet depletion in this study.

CLINICAL SIGNIFICANCE

Thrombocytopenia in cats may be more prevalent than previously reported and severe thrombocytopenia may be associated with spontaneous haemorrhage. Severe thrombocytopenia in cats appears less commonly immune-mediated than in dogs. Thrombocytopenia did not appear to be associated with retroviral infections.

Surgical management of impalement injuries to the trunk of dogs: a multicentre retrospective study

OBJECTIVES

To review a large series of dogs referred for treatment of traumatic impalement injuries to the thorax and/or abdomen and to report aetiologies, injury characteristics, management and long-term outcomes.

MATERIALS AND METHODS

Previously collected data on dogs that were surgically treated for impalement injuries to the trunk at six veterinary specialist referral institutions in the UK over an 11-year period were reviewed. Data included patient signalment, physiological variables, injury-specific variables, diagnostic imaging reports, surgical procedures undertaken, duration of hospitalisation, antibiotic use, complications and outcomes. Data were reported with summary statistics.

RESULTS

Fifty-four dogs were included. Impalement occurred most frequently on wooden objects (n=34), and the thoracic cavity was most commonly penetrated (n=37). Computed tomography was sensitive and specific to identifying wooden material in 64% and 88% of cases (n=11), respectively. Thoracotomy was performed in 56%, coeliotomy in 20% and a foreign body or its fragments were retrieved during surgery in 37% of the cases. Complications occurred in 19 dogs (35%), and of these, 68% were minor and 32% major. The survival rate for thoracotomy cases was 93% (n=30). Overall long-term survival was 90%.

CLINICAL SIGNIFICANCE

Despite the often dramatic presentation of impalement injuries, the majority of patients treated in the specialist referral setting can achieve excellent outcomes. These injuries require thorough diagnostic imaging and interpretation before adequate surgical exploration and management, augmented by anaesthesia and critical care during the peri- and postoperative periods; therefore stable patients should be referred to centres able to provide this type of care.

Effect of peritoneal lavage solution temperature on body temperature in anaesthetised cats and small dogs

A prospective, randomised, non-blinded, clinical study to assess the effect of peritoneal lavage using warmed fluid on body temperature in anesthetised cats and dogs of less than 10 kg body mass undergoing coeliotomy. A standardised anaesthetic protocol was used. Oesophageal and rectal temperatures were measured at various time points. At the end of surgery, group 1 patients (n=10) were lavaged with 200 ml/kg sterile isotonic saline at 34±1°C and group 2 (n=10) at 40±1°C. Groups were similar with respect to age, mass, body condition and surgical incision length. Duration of anaesthesia, surgical procedures and peritoneal lavage was similar between groups. Linear regression showed no significant change in oesophageal temperature during the lavage period for group 1 (P=0.64), but a significant increase for group 2 patients (P<0.0001), with mean temperature changes of -0.5°C (from (36.3°C to 35.9°C) and +0.9°C (from 35.4°C to 36.3°C), respectively. Similar results were found for rectal temperature, with mean changes of -0.5°C and +0.8°C (P=0.922 and 0.045), respectively. The use of isotonic crystalloid solution for peritoneal lavage at a temperature of 40±1°C significantly warms small animal patients, when applied in a clinical setting, compared with lavage solution at 34±1°C.

Surgical management of primary, metastatic and recurrent anal sac adenocarcinoma in the dog: 52 cases

OBJECTIVES

To report the outcomes and complications of a cohort of dogs with primary and recurrent anal sac adenocarcinoma managed with surgery as the first-line treatment. To report the use of lymph node cytology for identification of metastatic disease.

METHODS

Retrospective review of case records of a single referral centre population of dogs diagnosed with anal sac adenocarcinoma.

RESULTS

Fifty-two clinical cases were identified. Altered ultrasonographic appearance of lymph nodes was highly consistent with metastatic disease as assessed by cytology and histopathology. Seven of 58 (12%) perineal surgeries had reported minor complications and seven (12%) others required further surgical intervention. Minor controllable intraoperative bleeding was the only complication noted associated with lymph node extirpation in two of 39 (5%) metastectomy procedures. Six dogs (12%) suffered local recurrence and 22 (42%) developed subsequent or recurrent nodal metastatic disease. From the time of detection of disease recurrence, median additional survival associated with a second surgical intervention was 283 days.

CLINICAL SIGNIFICANCE

Coeliotomy for lymph node metastatectomy in dogs with adenocarcinoma of the anal sac has low morbidity and should be considered in patients presenting with evidence of regional metastatic disease both at initial presentation and with recurrent disease.

Short-term outcome and complications of TPLO using anatomically contoured locking compression plates in small/medium-breed dogs with "excessive" tibial plateau angle

OBJECTIVES

To report short-term radiographic and clinical outcome and complications following tibial plateau levelling osteotomy for the treatment of cranial cruciate ligament insufficiency in dogs less than 18·1 kg with tibial plateau angle greater than 35° using anatomically contoured six-hole locking compression plates.

METHODS

Retrospective data were collected on: preoperative, postoperative and follow-up tibial plateau angles, plateau segment rotation, tibial tuberosity width and length of the cranial aspect of tibial tuberosity segment from the patellar tendon insertion and rotation of the tibial plateau below the level of the insertion of the patellar ligament.

RESULTS

In 26 small dogs (29 stifles in total), mean preoperative, postoperative and follow-up tibial plateau angles were 38·2°, 4·8°, and 4·4°, respectively. Documented postoperative complications were limited to patellar tendinopathy in a single case (3·4%) and tibial tuberosity or fibula fracture were not observed.

CLINICAL SIGNIFICANCE

Short-term radiographic and clinical outcome of tibial plateau levelling osteotomy stabilised with anatomically contoured six-hole locking compression plates for the treatment of small dogs with large tibial plateau angle suggests a very low risk of complications. Rotation beyond the "safe point" is necessary to perform full rotation in some cases, but does not appear to incur an increased risk of tibial tuberosity fracture.

Pharmacologic interventions in nuclear medicine assessment of cardiac perfusion

Drugs that are currently used for therapeutic purposes can also be used in diagnostic tests. This paper will review the use of such pharmacological interventions in cardiac assessment in Nuclear Medicine. To fully comprehend the effect of these drugs, a small review of diagnostic nuclear medicine as currently used to assess cardiac perfusion is included. This will allow pharmacists to understand the rationale behind the single administration of either vasodilator or inotropic agents and to review which drugs and food may interact with the test.

Destabilization of the m = 1 diocotron mode in non-neutral plasmas

The theory for a Penning-Malmberg trap predicts m = 1 diocotron stability. However, experiments with hollow profiles show robust exponential growth. We propose a new mechanism of destabilization of this mode, involving parallel compression due to end curvature. The results are in good agreement with the experiments. The resulting modified drift-Poisson equations are analogous to the geophysical shallow water equations, and conservation of line integrated density corresponds to that of potential vorticity. This analogy predicts Rossby waves in non-neutral plasmas and an m = 1 instability in fluids.

Early recognition of sacroiliitis by magnetic resonance imaging and single photon emission computed tomography

OBJECTIVE

To evaluate the role of magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) in the detection of sacroiliitis in patients with clinical features of inflammatory back disease but without conventional radiographic changes.

METHODS

Twenty-four patients with inflammatory low back pain (ILBP) and normal or suspicious changes of sacroiliitis (New York criteria: 0-1) on conventional radiography, in addition to 12 control subjects were studied. MRI, bone and SPECT scans of the sacroiliac (SI) joints were obtained and interpreted without knowledge of patient identification. MRI scans were scored according to the modified New York criteria and examined for the presence of joint fluid, abnormalities in articular cartilage and in the underlying marrow signal. A quantitative and qualitative assessment of radiopharmaceutical uptake in the SI joints was derived from planar bone scan films and SPECT scans.

RESULTS

MRI detected features of scaroiliitis in 54% of patients with ILBP and in 17% of controls (p = 0.07). Quantitative and qualitative analysis of planar bone scan films did not reveal any differences between the 2 patient groups. In contrast, SPECT scanning identified sacroiliitis in 38% of patients with ILBP compared to none in controls (p = 0.05). When MRI and SPECT scanning were combined there was evidence of sacroiliitis in 63% of patients with ILBP and in 17% of controls (p = 0.025).

CONCLUSION

MRI and SPECT bone scanning provide objective and complementary evidence of sacroiliitis in patients with clinical features of inflammatory spinal disease in the absence of conventional radiographic changes.

Assessment of painful late effects of lumbar spinal fusion with SPECT

The authors reviewed planar, SPECT and other contemporaneous radiologic images of the spine and the medical records of 33 patients with back pain after lumbar fusion surgery in order to determine the value of SPECT in the assessment of painful late effects of spinal fusion surgery.

METHODS

Twenty-one patients had lateral fusion, nine patients had posterior fusion only and three patients had anterior and posterior fusions. There were 24 patients who had surgery more than 4 yr ago (late group, mean 11.8 yr) and 9 patients who had surgery less than 4 yr ago (early group, mean 17.8 mo).

RESULTS

The most common SPECT abnormality in patients in the late group were lesions in the vertebral bodies and apophyseal joints in the free motion segments adjacent to the fused segments (62.5% of patients). Such lesions occurred in 46% of patients after lateral fusion, in 87.5% of patients after posterior fusion and in 67% of patients after posterior and anterior fusions. No SPECT abnormalities were detected in the fused segments in patients in the late group with solid lateral fusion but were detected in three patients with solid posterior fusion. These results correlate with biomechanical studies that have shown posterior fusion to produce the largest amount and lateral fusion to produce the least amount of stress in the free segments adjacent to the fusion. Lateral fusion was found to have a more stabilizing effect than posterior fusion.

CONCLUSION

In addition to the already established value of SPECT in detecting painful pseudoarthrosis, our results indicate that SPECT is of value in the assessment of painful late effects of fusion.

Indium-111-white blood cell scintigraphy in Crohn's patients with fistulae and sinus tracts

METHOD

Indium-111-white blood cell (111In-WBC) images of 17 Crohn's patients with fistulae and sinus tracts were reviewed and correlated with radiographic results (n = 16 patients) and surgery (n = 16 patients), to characterize the scintigraphic appearance of fistulization and to determine the role of 111In-WBC scintigraphy in this clinical setting. These were compared to 50 consecutive abnormal 111In-WBC studies obtained in Crohn's patients with suspected active disease but no known fistulae or sinus tracts.

RESULTS

Scintigraphic findings which suggested the presence of fistulae were: (1) the presence of concomitant intestinal and extraintestinal lesions and (2) the absence of luminal activity on delayed images when early images detected bowel activity. The extraintestinal lesions were the drainage site of the fistula (n = 7) or an accompanying abscess (n = 6). Absence of luminal activity occurred in seven patients with fistulae and in two without fistulae; two patients had a proximal colostomy, two patients had bowel obstruction and five patients had fistulae to the skin (n = 3) or between the ileum and distal colon (n = 2). The distribution of active bowel disease as assessed scintigraphically was in complete agreement with surgery in 14 of 17 cases (82%) compared to 9 of 15 cases (60%) when correlating radiographic assessment with surgery. All surgically proven abscesses were detected on 111In-WBC images.

CONCLUSION

These results indicate that 111In-WBC scintigraphy adds useful information to radiographic studies that is essential for appropriate management of Crohn's patients with fistulae and sinus tracts.

Single photon emission computed tomography in the diagnosis of inflammatory spondyloarthropathies

OBJECTIVE

The role of bone scintigraphy in the evaluation of patients with inflammatory spondyloarthropathy is controversial and previous studies have reported a lack of sensitivity and specificity. The aim of our study was to determine whether single photon emission computed tomography (SPECT) scanning would enhance the clinical utility of bone scintigraphy in the detection of inflammatory axial disease, in particular sacroiliitis.

METHODS

Twenty patients with definite sacroiliitis (New York criteria > 1) on plain film radiographs and 20 age matched controls were studied. Bone scintigraphy and SPECT scanning were carried out 2 h after an intravenous injection of 99mTc imidodiphosphonate (IDP). A quantitative and qualitative assessment of radiopharmaceutical uptake in the sacroiliac (SI) joints was derived from planar films and a qualitative analysis of uptake in the SI joints was derived from SPECT scans. All films were read without knowledge of patient identification.

RESULTS

Quantitative analysis of planar films did not identify any difference between study and control groups (p > 0.05). Qualitative assessment of planar films identified features of sacroiliitis more frequently in patients than in controls (p < 0.05) with a sensitivity of 25% and a specificity of 95%. SPECT scanning also revealed enhanced radiopharmaceutical uptake in the SI joints more frequently in patients than in controls (p < 0.001) with a sensitivity of 85% and a specificity of 90%. Increased uptake in the lumbar facet joints and costovertebral joints was identified in 3 patients. Similar abnormalities were not detected in the control group.

CONCLUSION

Our results indicate that SPECT scanning is both sensitive and specific for the detection of established sacroiliitis and may also identify inflammatory disease at other sites in the spine.

Remnants of normal tissue in polycystic disease of the liver. A cause for difficulty in the interpretation of indium-111 white blood cell study

On In-111 WBC images, diffuse homogeneous uptake of the radiopharmaceutical should be present throughout the liver. The authors present a case of a febrile patient with polycystic liver disease in whom the normal diffuse uptake was not seen. Instead, the images demonstrated focal areas of uptake, which suggested infection. Tc-99m SC liver spleen scintigraphy demonstrated the In-111 WBC foci to correspond to areas of residual normal parenchyma. The patient underwent laparotomy and liver transplantation and no abscesses were found. Pathologic examination of the liver revealed multiple uninfected cysts and residual normal parenchyma in the caudate lobe, corresponding to the findings on scintigraphy.

The complementary role of hepatobiliary scintigraphy and abdominal sonography in a patient with a hepatic cyst and suspected acute cholecystitis

A 51-year-old woman was admitted with suspected acute cholecystitis. A large hepatic cyst was found incidentally by abdominal sonography, which displaced an "abnormal" gallbladder. Hepatobiliary scintigraphy visualized the gallbladder and excluded acute cholecystitis, but required the anatomic information from sonography to verify the abnormal location of the gallbladder. Additionally, scintigraphy showed the cyst not to communicate with the biliary tract. Pathologic findings revealed mild chronic cholecystitis and a simple mesothelial hepatic cyst. This case illustrates the complementary role of hepatobiliary scintigraphy and abdominal sonography in patients with distorted hepatobiliary anatomy and suspected acute cholecystitis.

180 degrees SPECT of the spine in patients with low back pain. Comparison with 360 degrees acquisition

Single-photon emission computed tomography has been proven to detect more abnormalities than planar bone scintigraphy in patients with low back pain (LBP). Both 180 degrees and 360 degrees acquisitions were performed in 24 patients with LBP to determine whether the shorter 180 degrees posterior SPECT is as accurate for abnormality detection as 360 degrees acquisition. The vertebral bodies and posterior elements of 193 vertebrae were scored on a five-point score (1 = normal, 5 = abnormal), independently by three experienced physicians, on three separate reconstructed image sets: standard, filtered, back projection 360 degrees acquisition, distance-weighted 360 degrees acquisition, and standard, filtered, back projection 180 degrees acquisition. With one exception, no statistically significant difference in score was found between 180 degrees and 360 degrees images. For one observer, the mean score of the posterior elements was higher on 180 degrees compared to 360 degrees standard images. These results indicate that 180 degrees acquisition SPECT may be used for abnormality detection in patients with LBP.

Role of SPECT in differentiating malignant from benign lesions in the lower thoracic and lumbar vertebrae

The authors categorized 125 spinal lesions in cancer patients and 127 lesions in patients with back pain according to their location in the vertebra on single photon emission computed tomographic (SPECT) images. Forty-four lesions were metastases, all in patients with known malignancy. Lesions in the apophyseal joints were all benign. Lesions manifesting as abnormal uptake projecting beyond the vertebral body surface were osteophytes. Thirty-seven percent of the lesions detected in cancer patients were categorized in either of these two benign categories. Lesions showing focal or diffuse uptake in the body were usually benign (96% and 87%, respectively). Lesions showing uptake in the body and pedicle were usually metastases (83%). When abnormal uptake was seen in both the body and posterior elements but with an intervening normal pedicle, benign disease was the most common cause (93%). It was concluded that the location of lesions on tomographic images provides useful information for differentiation between malignant and benign lesions in the vertebrae.

Magnetic resonance imaging in the detection of sacroiliitis

The value of magnetic resonance imaging (MRI) in establishing the diagnosis of sacroiliitis was studied in 20 patients with established or suspected disease on conventional radiographs and in 10 healthy subjects. Coronal T1 weighted, axial T2 weighted and proton density MRI images of the sacroiliac joints in addition to plain film radiographs were obtained. All films were graded from 0 to 4 according to the modified New York criteria and independently for changes in joint width, erosions, sclerosis and ankylosis. Using the modified New York criteria, more abnormalities were detected by MRI than by conventional radiography (p = 0.04). This was due to the detection of definite abnormalities (grades 2-4) by MRI in joints that were graded normal or suspicious (grades 0-1) on plain films (p = 0.01). MRI tended to be superior to plain films in visualizing erosions. Only MRI detected abnormalities of articular cartilage (19 patients) and in subchondral bone marrow (7 patients). The latter 2 types represented fatty infiltration and inflammatory change. Intraobserver and interobserver variation were similar for the interpretation of MRI scans and plain film radiographs. These results suggest that MRI detects changes of established sacroilitis. Due to its ability to directly image articular cartilage it may be particularly useful in patients with early disease.

Serum immunoreactive erythropoietin in HIV-infected patients

Serum immunoreactive erythropoietin (SIE) and hemoglobin levels were measured in 152 patients infected with the human immunodeficiency virus. Anemia was present in 18% of asymptomatic patients who tested positive for the human immunodeficiency virus, 50% of patients with a condition related to the acquired immunodeficiency syndrome (AIDS), and 75% of patients with AIDS. The mean SIE level for untreated AIDS patients (26.2 +/- 2.4 mU/mL) was greater than for patients who tested positive for human immunodeficiency virus or patients with an AIDS-related condition but not outside the normal range for SIE (4 to 26 mU/mL), and the incremental increase in SIE level for a given decline in hemoglobin level was much less in AIDS patients than in patients with uncomplicated iron deficiency anemia. Forty-two patients were treated with zidovudine, and the hemoglobin level fell 10 g/L or more in 48%. In contrast to the untreated patients, however, the mean SIE level rose 10-fold to 214 mU/mL, and the incremental change in SIE level for a given decline in hemoglobin level was markedly increased. In the zidovudine-treated patients, erythrocyte mean corpuscular volume also rose significantly from a mean of 88.1 fL to 102 fL. However, in only 1 patient was there a corresponding increase in reticulocytes and in none was there amelioration of anemia. The data indicate that SIE level is inappropriately low in anemic AIDS patients. The ability of these patients to produce erythropoietin is intact and can be expressed with zidovudine therapy. However, even very high levels of SIE fail to stimulate erythropoiesis adequately.