Imaging of pancreatic transplant vessels and anastomoses with 16-row multidetector computed tomography

The aim of this study was to evaluate the usefulness of 16-row multidetector computed tomography (16-MDCT) in the assessment of the potency of arterial and venous vessels in combined kidney-pancreas transplant and detection of transplant-related complications. Fifteen patients underwent a combined kidney-pancreatic transplantation. On the seventh day after the operation, we performed 16-MDCT in arterial and portal venous phase to evaluate vessels, anastomotic sites, and pancreatic parenchymal vascularization as well as peripancreatic fluid collections. We visualized the pancreatic vessels and anastomosis sites in all cases. In 12 recipients, there were no abnormal findings as regards the patency of the arterial and venous vessels and the vascularization of the pancreatic parenchyma. In two patients, complete arterial thrombosis of the body and tail pancreatic graft vessels was recognized at 2 weeks after transplantation, resulting in graft removal. Thrombi were localized in the distal part of anastomoses. None of the patients had venous thrombosis. One recipient had stenosis of the venous anastomosis. Peripancreatic fluid collections were observed in seven patients. In conclusion, 16-MDCT is an efficient method to estimate pancreatic transplant vessels, localize thrombi, and detect other transplant-related complications.     

Efficacy of spiral computed tomography in evaluation of renal arteries in patients with renovascular hypertension

The aim of this study is an estimation of efficacy of spiral computed tomography (SCT) in evaluation renal arteries in patients with renovascular hypertension. SCT was performed in 54 patients (32 females and 22 males) by means of Picker PQ 2000. The thickness 4 mm, index 4 mm, pitch 1.0. Contrast agents-Uropolinum 75% or Ultravist 350 were applied automatically 3-4 mm/sec. with delay 20-22 sec. Secondary reconstruction with 2 mm leyers was performed by Maximum Intensity Projection (MIP). In all patients the abdominal arteriography was performed as a reference method. The coincidence of both methods in evaluation of renal arteries occlusion or stenosis was estimated by Cohen kappa coefficient. In addition, sensitivity and specificity of SCT were estimated. RESULTS: Consistence of SCT and arteriography for right, left and additional renal artery were as follows: 0.914, 0.92, 0.85. Sensitivity and specificity SCT for rigt, left and additional renal artery were as follows: 95.5% and 95.8%, 96.5% and 95.8%, 50% and 100%. The highest efficacy of SCT was noted in ostium, the most difficult place in evaluation of renal artery during arteriography examination.     

What parameters from 18F-FDG PET/CT are useful in evaluation of adrenal lesions?

Purpose

Prior studies have suggested that ¹⁸F-FDG PET/CT can help characterize adrenal lesions and differentiate adrenal metastases from benign lesions. The aim of this study was to assess the value of ¹⁸F-FDG PET/CT for the differentiation of malignant from benign adrenal lesions.

Methods

This retrospective study included 85 patients (47 men and 38 women, age 63.8?±?10.8 years) who had undergone ¹⁸F-FDG PET/CT (60 min after injection 300 – 370 MBq ¹⁸F-FDG; Biograph 64 scanner) for evaluation of 102 nonsecreting adrenal masses. For semiquantitative analysis, the maximum standardized uptake value (SUVmax), adrenal to liver (T/L) SUVmax ratio, mean CT attenuation value and tumour diameter were measured in all lesions and compared with the pathological findings.

Results

Malignant adrenal tumours (68 % of evaluated tumours) had a significantly higher mean SUVmax (13.0?±?7.1 vs. 3.7?±?3.0), a higher T/L SUVmax ratio (4.2?±?2.6 vs. 1.0?±?0.9), a higher CT attenuation value (31.9?±?16. 7 HU vs. 0.2?±?25.8 HU) and a greater diameter (43.6?±?23.7 mm vs. 25.6?±?13.3 mm) than benign lesions. The false-positive findings were tuberculosis and benign phaeochromocytoma. Based on ROC analysis, a T/L SUVmax ratio >1.53, an adrenal SUVmax >5.2, an attenuation value >24 HU and a tumour diameter >30 mm were chosen as the optimal cut-off values for differentiating malignant from benign tumours. The areas under the ROC curves for the selected cut-off values were 0.96, 0.96, 0.88 and 0.77, respectively. A multivariate logistic regression model revealed that the T/L SUVmax ratio was an independent prognostic factor for malignancy (p?25 HU and a tumour diameter >30 mm had no additional individual importance in the diagnosis of malignancy.

Conclusion

Using a T/L SUVmax ratio >1.53 and an adrenal SUVmax >5.2 in ¹⁸F-FDG PET/CT led to high diagnostic sensitivity, specificity and negative predictive value for characterizing adrenal tumours. The diagnostic accuracies of the two parameters were comparable, but T/L SUVmax ratio was an independent predictor of malignancy.     

Quality of Pancreatic Transplant Program Assessment Using a Risk-adjusted Cumulative Sum Chart: Experience From a Single,Small Center

Background

The high rate of complication after pancreas transplantation not only had an impact on recipient quality of life and survival but also had significant financial implications. Thus, monitoring transplant center performance was crucial to indentifying changes in clinical practice that result in quality deterioration.

Objective

To evaluate retrospectively the quality of the single, small pancreatic transplant program and to establish prospective monitoring of the center using risk-adjusted cumulative sum (CUSUM).

Methodology

From 1988 to 2014, 119 simultaneous pancreas and the kidney transplantations (SPKTx) were performed. The program was divided into 3 eras, based on surgical technique and immunosuppression. Analyses of the 15 fatal outcomes due to complication from pancreatic graft were performed. The risk model was developed using multivariable logistic regression analysis based on retrospective data of 112 SPKTx recipients. The risk-adjusted 1-sided CUSUM chart was plotted for retrospective and prospective events. The upper control limit was set to 2.

Results

There were 2 main causes of death: multiorgan failure (73.3%; 11/15) and septic hemorrhage (26.7%; 4/15). Quality analysis using the CUSUM chart revealed that the process was not homogeneous; however, no significant signal of program deterioration was obtained and the performance of the whole program was within the settled control limit.

Conclusion

For a single pancreatic transplant center. The risk-adjusted CUSUM chart was a useful tool for quality program assessment. It could support decision making during traditional surgical morbidity and mortality conferences. For small transplant centers, increasing the sensitivity of the CUSUM method by lowering the upper control limit should be considered. However, an individual assessment approach of the for particular centers is recommended.     

Role of 16-Multidetector Computerized Tomography in Evaluation of Graft Failure Risk in Patients with Pancreatic Graft Thrombosis After Simultaneous Pancreas and Kidney Transplantation

Background

Thrombosis of the pancreatic graft vessels is a common complication in patients after pancreas transplantation. The aim of this study was to evaluate the usefulness of 16-multidetector computerized tomography (16-MDCT) with volume rendering (VR) and maximum intensity projection (MIP) reconstruction as a predicting method of pancreatic graft loss after simultaneous pancreas and kidney transplantation.

Methods

Within 6–8 days after combined kidney-pancreas transplantation, MDCT was performed in 60 patients. Secondary reconstructions were obtained with the application of VR and MIP algorithms. Vessel anastomosis, extra- and intrapancreatic arteries, venous morphology, and enhancement of graft's parenchyma were evaluated. The stenosis grade of pancreatic graft vessels and the areas of graft parenchyma malperfusion were evaluated.

Results

Thrombosis of pancreatic graft vessels was recognized in 26 patients (43%), however only one-half of them required graftectomy. There were 17 cases of large vessel thrombosis and 9 cases of small intragraft vessel thrombosis. In 13 (86.6%) out of 15 recipients parenchymal malperfusion resulted in graft lost. It appeared that vessel narrowing >40% was a threshold for pancreatic graft loss with sensitivity and false positive values of 100% and 9%, respectively. For parenchyma nonenhancement >60% the sensitivity and false positive values of 100% and 0% were significantly associated with pancreatic graft loss (P < .0001).

Conclusions

Vascular occlusion of >40% and necrosis >60% of parenchymal volume correspond with pancreatic graft loss.     

Usefulness of 16-Row Multidetector Computed Tomography With Volume Rendering and Maximum Intensity Projection Reconstruction as a Monitor Pancreatic Graft Vessel Patency During the Early Postoperative Period

Thrombosis of the pancreatic graft vessels is the most common complication after transplantation. It leads to loss of 5% to 8% of grafts during the early postoperative period. The aims of this study were to evaluate the usefulness of 16-row multidetector computed tomography (16-MDCT) with volume rendering (VR) and maximum intensity projection (MIP) reconstruction to monitor pancreatic graft vessel patency during the early postoperative period and the efficacy of a heparin infusion as a treatment for graft thrombosis. Among 40 consecutive simultaneous pancreas-kidney transplant recipients, 16-MDCT was performed at 6 to 8 days after the operation. Secondary reconstructions were obtained with VR and MIP algorithms to evaluate the morphology and patency of the extra- and intrapancreatic arteries and veins. In cases of thrombosis, every patient was treated with an infusion of unfractionated heparin. In 15 recipients, thrombosis of the large vessels was detected by 16-MDCT. Heparin infusions saved five pancreatic grafts (5/15; 33.3%), but the other 10 pancreatic grafts were removed. In another four recipients (4/40; 10%) the thrombi were localized only in small intrapancreatic vessels. Treatment with heparin infusion was successful in 3/4 (75%) cases with patent vessels upon control computed tomography examination. We compared the efficacy of heparin treatment depending on the diameter of the thrombosed vessel, observing a significant difference (5/15 vs 3/4; P < .01; chi-square). 16-MDCT with secondary reconstruction by application of VR and MIP algorithms was an efficient method to visualize not only large pancreatic graft arteries and veins but also intrapancreatic parenchymal vessels. In cases of thrombosis of small intrapancreatic vessels, unfractionated heparin infusion significantly decreased graft loss.     

Does saddle embolism influence short-term prognosis in patients with acute pulmonary embolism?

BACKGROUND: In some patients with acute pulmonary embolism (APE) thrombi may lodge at the levels of the bifurcation of pulmonary trunk and extend into both main pulmonary arteries, forming so-called saddle embolism (SE). AIM: To assess the incidence of SE and whether it is associated with an increased risk of complicated clinical course. METHODS: We studied 150 consecutive patients (94 females, 56 males) aged 63.6+/-16.7 years with APE confirmed with contrast enhanced spiral computed tomography or transesophageal echocardiography. RESULTS: SE was detected in 22 (14.7%) patients. Mean age (SE vs N-SE) was 64.3+/-17.4 vs 63.5+/-16.6 years, heart rate 100.8+/-14.1 beats/min vs 97.8+/-21.1 beats/min, systolic blood pressure 126.2+/-20.1 vs 127.1+/-23.3 mmHg and blood pulsoximetry 92 (68-98) vs 91 (30-98) % (all differences NS). In patients with SE, echocardiographic signs of the right ventricular overload, defined as right to left ventricular end - diastolic ratio >0.6 with right ventricular hypokinesia and/or maximal tricuspid peak systolic gradient >30 mmHg with shortened acceleration time of pulmonary ejection <80 ms, were more frequent (77.3% vs 51.6%, p=0.04), as was the mid-systolic deceleration of pulmonary ejection velocity (77.3% vs 49.2%, p=0.04). Mortality and complicated clinical course rates were similar in patients with SE or N-SE (mortality: 4.5% vs 13.3%, NS, and complicated clinical course: 34.4% vs 25.0%, NS). CONCLUSIONS: Saddle pulmonary embolism is frequent, especially in patients with echocardiographic signs of impaired pulmonary ejection pattern. Saddle embolism does not indicate unfavourable clinical outcome and probably should not influence treatment selection.     

Effects of hypertonicity on water intake in the elderly: An age-related failure

Dehydration is a common clinical syndrome associated with many illnesses and treatments in the elderly. Prior studies have shown diminished sensation of thirst during water deprivation. It is currently unclear whether age-related decreases in thirst perception impair the defense against a hyperosmolar challenge. To examine the impact of water ingestion during hyperosmolality, young and old subjects were allowed free access to water during and after an intravenous infusion of 5% hypertonic saline. Cumulative water intake and serum osmolality were compared between seven healthy young (20–28 yrs) and seven healthy old (72–89 yrs) volunteers during and following a two hour hypertonic saline infusion at a rate of 0.06 ml.kg^-1 min^-1. Serum osmolality and water intake were markedly different between the two groups. In the old group, serum osmolality increased by 17 mosmol/kg above baseline despite free access to water. In contrast, serum osmolality increased to only 7 mosmol/kg above baseline in the young group and did not rise further. By ingesting water, the young were able to defend against an additional increase in serum osmolality. The young drank approximately twice that of the old during the infusion period. Healthy older individuals drink less than young despite a significantly increased serum osmolality. This hypodipsia in old individuals increases their susceptibility to hypertonicity.