Detection Of Vascular Complications Research Articles

Role of doppler ultrasound in detecting vascular complications in recipients of living donor liver transplant (LDLT).

To determine the role of Doppler ultrasound in the detection of vascular complications in recipients of living donor liver transplant, keeping contrast-enhanced computerised tomography of abdomen as the gold standard. The retrospective study was conducted from February 16 to April 1, 2022, at the Pakistan Kidney and Liver Institute and Research Centre, Lahore, Pakistan, and comprised data of living donor liver transplant recipients who had undergone contrast-enhanced computerised tomography of abdomen within 24 hours of Doppler ultrasound between January 2021 and January 2022. For the diagnosis of hepatic vascular complications, the diagnostic values of Doppler ultrasound parameters were derived by correlating Doppler ultrasound findings with contrast-enhanced computerised tomography results. Data was analysed using SPSS 20. Of the 35 patients, 24(68.6%) were men and 11(31.4%) were women. The overall mean age was 45.86±13.8 years. For hepatic artery thrombosis, the use of Doppler ultrasound criteria yielded a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 96.6%, 83.3%, 100%, and 97.1% respectively. For hepatic artery stenosis, overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Doppler ultrasound was 100%, 96.8%, 75%, 100% and 97.1% respectively. Doppler ultrasound parameters resulted in a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 100% each in detecting portal vein and hepatic venous outflow tract thrombosis. Overall, Doppler ultrasound sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy was found to be 100%, 88.8%, 89.4%, 100% and 94.2% respectively. Doppler ultrasound was adequate to document vascular complications after living donor liver transplant in majority of the cases with high accuracy and sensitivity.

Doppler Ultrasound of Vascular Complications After Pediatric Liver Transplantation: Incidence, Time of Detection, and Positive Predictive Value.

Purpose Doppler ultrasound (DUS) is widely used to detect vascular complications after pediatric liver transplantation (LT). This study aimed to assess the moment of first detection of vascular complications with DUS, and to determine the positive predictive value (PPV) of DUS. Materials and Methods Patients aged 0-18 years who underwent LT between 2015 and 2019 were retrospectively included. 92 LTs in 83 patients were included (median age: 3.9 years, interquartile range: 0.7-10.5). Patients underwent perioperative (intra-operative and immediately postoperative) and daily DUS surveillance during the first postoperative week, and at 1, 3, and 12 months. Vascular complications were categorized for the hepatic artery, portal vein, and hepatic veins. DUS findings were compared to surgical or radiological findings during the 1-year follow-up. Results 52 vascular complications were diagnosed by DUS in 35/92 LTs (38%). 15 out of 52 (28.8%) were diagnosed perioperatively, 29/52 (55.8%) were diagnosed on postoperative days 1-7, and 8/52 (15.4%) after day 7. The PPV for all vascular complications diagnosed with DUS was 92.3%. During the 1-year follow-up, 18/19 (94.7%) hepatic artery complications, 19/26 (73.1%) portal vein complications, and 7/7 (100%) hepatic vein complications were diagnosed perioperatively or during the first week. Conclusion The majority of vascular complications during the first year after pediatric LT were diagnosed by DUS perioperatively or during the first week, with a high PPV. Our findings provide important information regarding when to expect different types of vascular complications on DUS, which might improve DUS post-LT surveillance protocols.

Contrast-enhanced ultrasound for the evaluation of hepatic artery occlusion after liver transplantation

Introduction:Vascular complications after liver transplantation remain a major threat to the survival of recipients.HAT is a major cause of graft loss and patient mortality, with an incidence between 3% to 8% in transplant recipients.Early detection of HAT is critical because urgent revascularization is required to avoid severe graft loss. Although ultrasound is the preferred first-line imaging modality in patients with suspected HAT, the accuracy and positive predictive value of HAT on Doppler US are reported to be low. Moreover, Doppler examination of the hepatic vasculature is time consuming and requires a high level of operator skill. Conventional angiography remains the gold standard for diagnosis. Recently, contrast-enhanced ultrasound (CEUS) has begun providing real-time angiographic-like images of vessels at bed side and allowing the accurate diagnosis of arterial diseases such as hepatic artery thrombosis. The purpose of this study was to evaluate the efficacy of CEUS in detecting HAT after liver transplantation: Materials and Methods: This is a retrospective data of the medical records of patients undergoing Liver transplantation in the Osmania General Hospital, Hyderabad between 2016 to 2018. Status of hepatic vascular assessment following liver transplantation done by conventional Doppler Ultra sonography and Contrast Enhanced Ultrasonography tests were obtained from registries of medical records. Results:23 cases of post Liver transplantation aged between 4years and 58 years, with a median age of 30 years were included in the analysis. There were 20 males and 3 females. 14 patients underwent DDLT, 7 patients underwent LDLT, 1underwent split Liver transplantation and another 1 patient underwent Auto liver transplantation. Doppler US was inconclusive regarding patency of the hepatic artery (HA) circulation in 5 (21.7 %) of 23 transplantations. CEUS was performed in these 5 patients and detected HA thrombosis (HAT) in 2 cases and patent HA in 3 transplants. These 5 Transplants were confirmed by CT Angiography /conventional Angiography. In the subset of transplantations examined with CEUS, the sensitivity, specificity and accuracy of CEUS were 100%. CEUS was done at bedside without any Radiation and Nephro toxicity. In approximately 21.7% of cases, conventional Doppler US did not provide sufficient visualization of the HA after liver transplantation. In these cases, correct diagnosis was achieved by supplementary CEUS. Conclusion:CEUS may be a new approach for early diagnosis of postoperative vascular complications after Liver Transplantation, and it can be performed at the bedside. It is safe will not cause any nephron toxicity and Radiation. CEUS is a fast, non-ionizing imaging modality for the initial exclusion of vascular complications after liver transplantation. CEUS shows a high specificity and PPV in the detection of vascular complications. In unclear cases CT still is considered as the gold standard

Diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in monitoring vascular complications in patients after liver transplantation - diagnostic performance compared with histopathological results.

To analyse the diagnostic performance of contrast-enhanced ultrasound (CEUS) in patients with vascular complications and transplant rejection compared to histopathological results. Our study consisted of 45 retrospectively analysed patients that underwent liver transplantations between January 1993 and December 2015 and developed post-transplant vascular complications with transplant rejection. CEUS examinations took place between September 2006 and December 2015. CEUS findings were correlated with histopathological results. CEUS showed a sensitivity of 61.5%, a specificity of 100.0%, a positive predictive value (PPV) of 100.0% and a negative predictive value (NPV) of 86,5% in the detection of vascular complications with post-transplant rejection. 5 examinations were reported as normal whereas the histopathological result showed a transplant rejection (false-negative). CEUS might be a useful additional non-invasive technique for the assessment of vascular complications with post-transplant rejection in patients after liver transplantation.

Vascular complications in liver transplantation: Beneficial role ofcontrast-enhanced ultrasound (CEUS)inthepostoperative phase.

To compare the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) in the diagnosis of vascular complications after liver transplantation in the postoperative phase. A total of 60 patients with elevated liver function tests after liver transplantation with initial imaging studies between July 2005 and November 2015 were retrospectively analysed. CEUS and CT were compared in their diagnosis of vascular complications and CT was considered as the gold standard. Out of 60 patients 28 patients showed vascular complications in CT, which could also be detected in 25 out 28 of cases using CEUS. Diagnostic accuracy was tested by using the CT diagnosis as the gold standard. CEUS showed a sensitivity of 89.3%, a specificity of 100.0%, a positive predictive value (PPV) of 100.0% and a negative predictive value (NPV) of 91,4% compared to CT as the gold standard. In 3 cases CT showed a vascular complication, whereas the CEUS examination was reported as normal. CEUS is a fast, non-ionizing imaging modality for the initial exclusion of vascular complications after liver transplantation. CEUS shows a high specificity and PPV in the detection of vascular complications. In unclear cases CT still is considered as the gold standard.

Candida vascular complication in a liver transplant recipient due to yeast contamination of preservation solution

Infections remain a major cause of morbidity and mortality after liver transplantation. One possible cause of infection is preservation fluid contamination. Donor-derived pathogens, such as Candida albicans, have occasionally produced life-threatening complications in organ recipients, already described in renal transplantation. In the present case, we report the loss of a liver graft secondary to vascular complications because of C.albicans found in the preservation fluid. Our case report raises the question of implementing procedures, similar to those in renal transplantation, including early antifungal treatment and repeated radiological monitoring for the prevention and detection of vascular complications.

Emergency Imaging Assessment of Deep Neck Space Infections

Deep neck space infection may lead to severe and potentially life-threatening complications, such as airway obstruction, mediastinitis, septic embolization, dural sinus thrombosis, and intracranial abscess. The clinical presentation is widely variable, and often early symptoms do not reflect the disease severity. The complication risk depends on the extent and anatomical site: diseases that transgress fascial boundaries and spread along vertically oriented spaces (parapharyngeal, retropharyngeal, and paravertebral space) have a higher risk of complications and require a more aggressive treatment compared with those confined within a nonvertically oriented space (peritonsillar, sublingual, submandibular, parotid, and masticator space). Imaging has 5 crucial roles: (1) confirm the suspected clinical diagnosis, (2) define the precise extent of the disease, (3) identify complications, (4) distinguish between drainable abscesses and cellulitis, and (5) monitor deep neck space infection progression. Ultrasonography is the gold standard to differentiate abscesses from cellulitis, for the diagnosis of lymphadenitis. and to identify internal jugular thrombophlebitis in the infrahyoid neck. However, field-of-view limitation and poor anatomical information confine the use of ultrasonography to the evaluation of superficial lesions and to image-guided aspiration or drainage. Computed tomography (CT) combines fast image acquisition and precise anatomical information without field-of-view limitations. For these reasons, it is the most reliable technique for the evaluation of deep and multicompartment lesions and for the identification of mediastinal and intracranial complications. Contrast agent administration enhances the capability to differentiate fluid collections from cellulitis and allows the detection of vascular complications. Magnetic resonance imaging is more time-consuming than CT, limiting its use to selected indications. It is the technique of choice for assessing the epidural space involvement in pre- and paravertebral space infections and complements CT in the evaluation of the infections reaching the skull base.

Abstract No. 416: The role of 64 slice CT angiography in detection of vascular complications after liver transplantation

Abstract No. 416: The role of 64 slice CT angiography in detection of vascular complications after liver transplantation

TTP (time to PEAK) and RBV (regional blood volume) as valuable parameters to detect early flap failure

Free flap transplantation is used more and more frequently in order to cover extensive wound defects. The basic prerequisite for successful flap salvage after flap failure is a short time interval from failure until revision. For this reason many different flap monitoring systems have been tested over the last years. The aim of the experiment was to detect critical capillary perfusion using contrast enhanced ultrasound. Quantitative analysis should be performed by a special perfusion software (QONTRAST; Bracco, Italy) appraising digital raw data of contrast enhanced ultrasound (CEUS). Additionally diverse risk factors for free flap transplantation were determined. Thirty-one patients were examined after free flap transplantation during the first 72 hours after operation. CEUS was performed with a linear transducer (6-9 MHz, LOGIQ E9/GE) and a bolus injection of 2.4 ml of contrast agent (SonoVue, Bracco, Italy). Operation and examination were performed by either an experienced plastic surgeon or an experienced ultrasound examiner. Depth dependent capillary perfusion was analysed and quantitative perfusions analysis was performed using the perfusions software QONTRAST (Bracco, Italy). Eleven revisions had to be performed: 7 due to haematoma and 4 due to superficial necrosis. Reduced capillary perfusion was seen in all 11 complications using CEUS. Significant difference comparing the no complication and the complication group was observed using TTP (time to PEAK) and RBV (regional blood volume) quantitative analysis. Mean RBV was 922.1 ± 150.9 in the no complication and 303.0 ± 53.9 in the complication group (p = 0.001). Mean TTP was 37.6 ± 3.8 in the no complication and 21.3 ± 3.4 in the complication group (p = 0.006). Tendency to higher complication rate was seen in older male patients with vascular or malignant primary disease. In this clinical trial, capillary perfusion after free flap transplantation as well as detection of vascular complications was demonstrated using CEUS. Quantitative perfusions analysis could be performed and flap viability could be assessed easily.

Postoperative assessment of free skin flap viability by transcutaneous pO2 measurement using dynamic phosphorescence imaging

Free flap transplantation is used more and more frequently in order to cover extensive wound defects. The basic prerequisite for successful flap salvage after flap failure is a short time interval from failure until revision. For this reason many different flap monitoring systems have been tested over the last years. But none of them has made the way into clinical routine. The aim of this clinical study was to study whether luminescence lifetime imaging (LLI) is an adequate method to assess flap viability during the postoperative period. In previous experiments LLI was proven to be a precise and non-invasive monitoring system for transcutaneous oxygen measurement. ptcO2 of 9 patients was detected during a postoperative period of 72 hours. In all cases the transplantation was performed by the same experienced surgeon. During the first 4 hours almost constant ptcO2 values were detected (53±0.7 mmHg). During the following time intervals ptcO2 values decreased and reached a more or less constant level after approximately 12 hours. The mean ptcO2 decreased from 53±0.7 mmHg to 39±1.0 mmHg. In one case an immediate decrease of ptcO2 below 10 mmHg was observed and a subsequently intervention was necessary to improve flap perfusion. In this clinical trial, perfusion dynamics after free flap transplantation as well as the detection of vascular complications were demonstrated using LLI. Based on these data, LLI seems to be a sensitive and adequate monitoring system for the evaluation of free flap viability.

Sonographic Evaluation of Complications of Liver Transplantation

This article reviews several of the major complications that occur after liver transplantation and describes radiologic modalities used to diagnose and evaluate them. To illustrate the discussion, case presentations of five patients who under-went liver transplantation at the Nazih Zuhdi Transplantation Institute at Integris Baptist Medical Center in Oklahoma City are given. Many of the major complications of liver transplantation can be characterized as vascular or biliary in origin. Hepatic artery thrombosis is the most dreaded complication in the immediate postoperative period because it often necessitates retransplantation. Hepatic artery stenosis can alter graft function as well. Less common arterial complications include pseudoaneurysm formation, hepatic artery rupture and arteriovenous fistula formation. Venous complications include inferior vena cava and portal vein thrombosis and stenosis. Gray-scale and color Doppler ultrasound play a primary role in detection of vascular complications. Angiography or venography may be used for definitive diagnosis. Biliary complications, such as biliary leakage or stricture, occur with some frequency after transplantation and are best evaluated with sonography, cholangiography, and nuclear medicine studies. A late complication of liver transplantation is posttransplant lymphoproliferative disorder, which may be detected and evaluated by ultrasound, computed tomography, and magnetic resonance imaging. Graft rejection is better detected by nonradiologic means.

Detection of Vascular Complications After Liver Transplantation

Our objective was to investigate the usefulness of three-dimensional multislice CT angiography for the evaluation of liver transplant recipients presenting with clinical or sonographic findings suggestive of hepatic vascular complications. Our early results indicate that three-dimensional multislice CT angiography with volume rendering can reveal common and potentially lethal vascular complications in patients who have undergone liver transplantation.

Imaging of vascular complications associated with renal transplants.

Vascular complications associated with renal transplants are a significant cause of graft dysfunction. The most common complications are arterial and venous stenoses and thromboses and intrarenal and extrarenal arteriovenous fistulas and pseudoaneurysms. Although angiography is the imaging gold standard for the diagnosis of these disorders, Doppler sonography, scintigraphy, and occasionally CT are capable of detecting them. An awareness of the different imaging appearances of each complication will aid in their early detection and treatment. In this review, we present this information and provide a perspective on the relative roles of these techniques in the detection of vascular complications from renal transplants.

Detection of Vascular Complications in Renal Allografts with Color Doppler Flow Imaging

Detection of Vascular Complications in Renal Allografts with Color Doppler Flow Imaging

Detection of vascular complications in renal allografts with color Doppler flow imaging.

One hundred ninety-five color Doppler flow (CDF) examinations were performed in 146 renal allografts to assess the capabilities of this technique in detecting intra- or extrarenal vascular complications. Conventional angiography was also performed in 44 transplants. In the group of transplants with angiographic correlation, CDF sonography enabled correct identification of 30 of 34 vascular complications. CDF showed 10 of 11 significant stenoses of the renal artery or of one of its main branches. There were two false-positive renal artery stenoses (one normal artery and one 40% stenosis). Nine of nine renal artery thromboses and the single pseudoaneurysm were also identified. Within the parenchyma, CDF sonography demonstrated five of five segmental infarcts, two of two postbiopsy arteriovenous fistulas, and three of six segmental or interlobar artery stenoses. Measurement of peak systolic velocity showed a significant difference (P less than .05) between a group (n = 8) with significant stenosis of the renal artery or one of its main branches (mean, 215.2 cm/sec +/- 32) and a group (n = 14) without stenosis (mean, 99.2 cm/sec +/- 19).

Detection of vascular complications by plethysmography during direct vessel surgery.

Detection of vascular complications by plethysmography during direct vessel surgery.