Interventional Management of Acquired Lymphatic Disorders.

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ©RSNA, 2022.

Transsplenic Portal System Catheterization: Review of Current Indications and Techniques.

Multiple diseases of the portal system require effective portal vein access for endovascular management. While percutaneous transhepatic and transjugular approaches remain the standard methods of portal vein access, transsplenic access (TSA) has gained recognition as an effective and safe technique to access the portal system in patients with contraindications to traditional approaches. Recently, the utility of percutaneous TSA has grown, with described treatments including recanalization of chronic portal vein occlusion, placement of stents for portal vein stenosis, portal vein embolization of the liver, embolization of gastric varices, placement of complicated transjugular intrahepatic portosystemic shunts, and interventions after liver transplant. The authors provide a review of percutaneous TSA, including indications, a summary of related portal vein diseases, and the different techniques used for access and closure. In addition, an imaging-based review of technical considerations of TSA interventions is presented, with a review of potential procedural complications. With technical success rates that mirror or rival the standard methods and reported low rates of major complications, TSA can be a safe and effective option in clinical scenarios where traditional approaches are not feasible. ©RSNA, 2022.

Interventional Radiology Management of Adult Liver Transplant Complications.

Liver transplant remains the definitive therapy for patients with end-stage liver disease. Outcomes have continued to improve, in part owing to interventions used to treat posttransplant complications involving the hepatic arteries, portal vein, hepatic veins or inferior vena cava (IVC), and biliary system. Significant hepatic artery stenosis can be treated with angioplasty or stent placement to prevent thrombosis and biliary ischemic complications. Hepatic arterioportal fistula and hepatic artery pseudoaneurysm are rare complications that can often be treated with endovascular means. Treatment of hepatic artery thrombosis can have mixed results. Portal vein stenosis can be treated with venoplasty or more commonly stent placement. The rarer portal vein thrombosis can also be treated with endovascular techniques. Hepatic venous outflow stenosis of the hepatic veins or IVC is amenable to venoplasty or stent placement. Complications of the bile ducts are the most encountered complication after liver transplant. When not amenable to endoscopic intervention, biliary stricture, bile leak, and ischemic cholangiopathy can be treated with percutaneous transhepatic cholangiography with biliary drainage and other interventions. New techniques have further improved care for these patients. Transsplenic portal vein recanalization has improved transplant candidacy for patients with chronic portal vein thrombosis. Spontaneous splenorenal shunt and splenic artery steal syndrome (nonocclusive hepatic artery hypoperfusion syndrome) remain complicated topics, and the role of endovascular embolization is developing. When patients have recurrence of cirrhosis after transplant, most commonly due to viral hepatitis, transjugular intrahepatic portosystemic shunt (TIPS) may be required to treat symptoms of portal hypertension. Online supplemental material is available for this article. ©RSNA, 2022.

Detection of Bleeding Complications After Renal Transplant Biopsy.

OBJECTIVE. The purpose of this study was to analyze the timing of major bleeding complications after renal transplant biopsy in the context of a standardized 1-hour postprocedure observation protocol. MATERIALS AND METHODS. We retrospectively reviewed the electronic medical records for consecutive patients who underwent ultrasound-guided renal transplant biopsies between January 1, 2012, and December 31, 2017, and were observed according to a newly implemented 1-hour postprocedure observation protocol. The development of a major bleeding complication (Common Terminology Criteria for Adverse Events class 3 or higher) was recorded along with all available details regarding the time course of patient symptoms and presentation. Complications were grouped into one of four categories according to onset time after biopsy: 2 hours or less (timing category 1), more than 2 hours but 4 hours or less (timing category 2), more than 4 hours but 8 hours or less (timing category 3), and more than 8 hours (timing category 4). RESULTS. In 1824 patients (769 women, 1055 men) who underwent 4519 consecutive ultrasound-guided renal transplant biopsies during the study period, 11 class 3 complications were found (11/4519 [0.2%]). Four of the 11 patients (36.4%) had symptoms during the 1-hour observation period. Of these four patients, three (3/11 [27.3%]) had substantial symptoms related to major bleeding and were classified as timing category 1, and one (1/11 [9.1%]) had initially minor symptoms that increased in severity more than 2 hours but within 4 hours and was classified as timing category 2. Seven of the 11 patients (63.6%) did not have any symptoms at 1 hour of observation and were discharged; three (27.3%) were classified as timing category 3, and four (36.4%) were classified as category 4. CONCLUSION. Major bleeding complications following ultrasound-guided renal transplant biopsy are rare (0.2% of patients in this study). In our study, more than half were not clinically apparent within 4 hours of biopsy. A 1-hour postprocedure recovery period can be safely used after renal transplant biopsy.

Added Benefit and Risk of an Additional Biopsy or Targeting With Contrast-Enhanced Ultrasound for Patients With Renal Transplants.

OBJECTIVES: To determine whether renal transplant diagnoses substantially change when 2 biopsy sites are chosen and whether contrast-enhanced ultrasound (CEUS) has value for targeting the second site. METHODS: We prospectively enrolled 40 patients undergoing ultrasound-guided renal transplant biopsy within 2 years of transplant: 20, surveillance; and 20, for cause. A CEUS examination was performed to identify cortical regions with subjectively altered flow. One biopsy was performed at the operator-preferred (primary) site regardless of CEUS findings. Another biopsy was done at a second location, either targeted to an area in which CEUS perfusion findings differed from the primary site (targeted) or at a random location (secondary) if no other area differed. Specimens were randomly labeled A or B; pathologists were blinded to the CEUS result and biopsy location. Location-specific CEUS assessments were recorded. Pathologic results were compared, including acute and chronic Banff scores and any new findings from the targeted or secondary biopsy. RESULTS: Forty patients were enrolled between January 2016 and December 2018. No location-specific pathologic differences correlated with differences in CEUS assessments. The second biopsy provided additional information that changed management in 4 of 40 patients (10.0% [95% confidence interval, 2.8%-23.7%]). Major bleeding complications occurred in 3 of 40 (7.5%) patients. CONCLUSIONS: Contrast-enhanced ultrasound targeting was not useful. Major bleeding complications were higher than expected, possibly due to the additional biopsy away from the operator-preferred location. Obtaining a second renal transplant biopsy from a substantially different area than the initial operator-preferred location provided additional clinically useful information in 10% of patients.

Pleural "drop metastases" 21 years after resection of a thymoma.

INTRODUCTION: We describe an unusual case of pleural drop metastases 21 years after complete resection of an encapsulated thymoma in a Southeast Asian patient with myasthenia gravis (MG). METHODS: This investigation includes a case report and brief review of the literature. RESULTS: The patient presented in 2015 with generalized weakness, fatigue, and shortness of breath, but no diplopia, ptosis, dysphagia, or dysarthria. Because these symptoms were atypical for an MG exacerbation, a de-novo work-up was performed. Chest computed tomography (CT) showed numerous pleural nodules ("drop metastases"), and CT-guided biopsy revealed metastatic thymoma. CONCLUSIONS: The average disease-free interval for thymoma ranges from 68 to 86 months. Pleural and mediastinal recurrence are more common than distant hematogenous recurrence. Adverse prognostic factors include an initial higher Masaoka stage, incomplete resection, older age, and pleural or pericardial involvement. Despite apparent complete resection of thymoma, clinicians should remain vigilant for recurrence for as long as 20 years after initial management. Long-term follow-up with radiologic surveillance is recommended. Muscle Nerve 56: 171-175, 2017.

Factors Contributing to the Success of Ultrasound-Guided Native Renal Biopsy.

OBJECTIVES: The purpose of this study was to evaluate factors contributing to the success of ultrasound-guided native renal biopsy. METHODS: We retrospectively identified patients who had ultrasound-guided native renal biopsy at our institution over a 10-year period. We reviewed the imaging and electronic medical records to collect demographic information and clinical data, including pathologic results. Biopsy samples were categorized and compared on the basis of the number of glomeruli (optimal [≥20] versus suboptimal [<20]) and the pathologist's reported diagnostic confidence (high confidence versus limited confidence). Procedure details, including the operator and the use of the cortical tangential approach, were also obtained. RESULTS: For 282 patients with biopsies using 18-gauge needles, the number of passes made was significantly higher for optimal (P < .001) and high-confidence (P < .001) specimens than for suboptimal and limited-confidence specimens. The cortical tangential approach was used more frequently for optimal (P< .001) and high-confidence (P = .01) specimens than for suboptimal and limited-confidence specimens. Radiologists routinely doing ultrasound-guided procedures of all types had significantly more optimal (P= .01) and high-confidence (P= .001) specimens than radiologists with limited ultrasound experience. The distance to the kidney, cortical thickness, glomerular filtration rate, and body mass index were not significant factors. CONCLUSIONS: The ultrasound-guided procedural experience of the operator, taking more than 1 specimen, and the use of the cortical tangential approach significantly improved the pathologic material obtained during native renal biopsies.

Risk of bleeding after native renal biopsy as a function of preprocedural systolic and diastolic blood pressure.

PURPOSE: To determine the risk of bleeding complications after native renal biopsy as a function of preprocedural blood pressure (BP). MATERIALS AND METHODS: A total of 293 patients (163 men; mean age, 59.1 y) who underwent ultrasound-guided native kidney biopsy at a single institution over a 10-year period were retrospectively identified. Demographic and clinical data were collected, including systolic BP (SBP) and diastolic BP (DBP) at the time of the biopsy and presence and severity of complications. Differences in clinical and demographic data among patients with and without complications were analyzed. RESULTS: Of 293 patients, nine (3.1%) experienced major complications (required transfusion or intervention) and 10 (3.4%) experienced minor complications (pain, hematoma, or hematuria). Patients with SBP greater than 140 mm Hg or DBP greater than 90 mm Hg were 10 times more likely to experience major complications (P < .02) than patients without high BP (odds ratio [OR], 10.6; 95% confidence interval [CI], 1.3-86.0). The odds of complications were particularly increased in patients with SBP greater than 170 mm Hg (OR, 23.3; 95% CI, 2.3-234.4) and were modestly increased in patients with SBP between 141 and 170 mm Hg (OR, 7.11; 95% CI, 0.8-61.7). For DBP, the odds of complications increased with DBP greater than 90 mm Hg (OR, 7.2; 95% CI, 1.9-27.9). CONCLUSIONS: Patients undergoing native renal biopsy who have an SBP greater than 140 mm Hg or DBP greater than 90 mm Hg are at higher risk for bleeding complications. Further research is needed to determine whether medically lowering these patients' BP before kidney biopsy decreases complications.

Portomesenteric venous thrombosis following major colon and rectal surgery: incidence and risk factors.

BACKGROUND: Portomesenteric venous thrombosis (PMVT) is an uncommon complication of abdominal surgery. The objective of this study was to assess PMVT risk factor profiles and patient outcomes after colorectal surgery. METHODS: A single center retrospective review of patients undergoing colorectal surgery was performed (2007-2012). PMVT was defined as thrombus within the portal, splenic, or superior mesenteric vein on computed tomography (CT). Inferior mesenteric vein thrombosis was excluded. Independent samples t test was used to compare data variables between PMVT and non-PMVT patients. Univariate and multivariate logistic regression analyses were used to assess PMVT risk factors. RESULTS: There were 1,224 patients included (mean age 62 years, male = 566). Elective bowel resection was performed for colon carcinoma (n = 302), rectal carcinoma (n = 112), ulcerative colitis (n = 125), Crohn's disease (n = 78), polyps (n = 117), and diverticulitis (n = 215). Patients undergoing gynecological resections and emergent laparotomies were included (n = 275). Thirty-six patients (3%) were diagnosed with PMVT by CT: 17/36 on initial presentation and 19/36 by expert radiologist review. Patients with PMVT were younger (53 vs. 62 years, p = 0.001) with higher BMI (30.5 vs. 26.7, p < 0.001) and thrombocytosis (464 vs. 306, p < 0.001) compared to patients without PMVT. Univariate logistic regression identified younger age (p < 0.001), obesity (p < 0.001), ulcerative colitis (p < 0.001), thrombocytosis, (p < 0.001) and proctocolectomy as significant predictors of PMVT. Stepwise multivariate logistic regression identified that obesity (p < 0.001), thrombocytosis, (p < 0.001) and restorative proctocolectomy (p = 0.001) were still significant predictors. No patients in the PMVT group suffered bowel infarction and no related mortalities occurred. Thirty-day readmission rates were higher in the PMVT group (53% vs. 17%, p < 0.01). CONCLUSION: BMI ≥ 30 kg/m(2), thrombocytosis, and restorative proctocolectomy were significant predictors of PMVT. Initial diagnostic studies showed a PMVT rate of 1.4%; however, after expert focused radiologic review, the actual rate was 3%. Thus, the diagnosis of PMVT is difficult and readmission after colorectal surgery should prompt its consideration.

Ultra-low-dose computed tomographic angiography with model-based iterative reconstruction compared with standard-dose imaging after endovascular aneurysm repair: a prospective pilot study.

PURPOSE: An ultra-low-dose radiation protocol reconstructed with model-based iterative reconstruction was compared with our standard-dose protocol. METHODS: This prospective study evaluated 20 men undergoing surveillance-enhanced computed tomography after endovascular aneurysm repair. All patients underwent standard-dose and ultra-low-dose venous phase imaging; images were compared after reconstruction with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction. Objective measures of aortic contrast attenuation and image noise were averaged. Images were subjectively assessed (1 = worst, 5 = best) for diagnostic confidence, image noise, and vessel sharpness. Aneurysm sac diameter and endoleak detection were compared. RESULTS: Quantitative image noise was 26% less with ultra-low-dose model-based iterative reconstruction than with standard-dose adaptive statistical iterative reconstruction and 58% less than with ultra-low-dose adaptive statistical iterative reconstruction. Average subjective noise scores were not different between ultra-low-dose model-based iterative reconstruction and standard-dose adaptive statistical iterative reconstruction (3.8 vs. 4.0, P = .25). Subjective scores for diagnostic confidence were better with standard-dose adaptive statistical iterative reconstruction than with ultra-low-dose model-based iterative reconstruction (4.4 vs. 4.0, P = .002). Vessel sharpness was decreased with ultra-low-dose model-based iterative reconstruction compared with standard-dose adaptive statistical iterative reconstruction (3.3 vs. 4.1, P < .0001). Ultra-low-dose model-based iterative reconstruction and standard-dose adaptive statistical iterative reconstruction aneurysm sac diameters were not significantly different (4.9 vs. 4.9 cm); concordance for the presence of endoleak was 100% (P < .001). CONCLUSION: Compared with a standard-dose technique, an ultra-low-dose model-based iterative reconstruction protocol provides comparable image quality and diagnostic assessment at a 73% lower radiation dose.

Primary percutaneous treatment of transplant ureteral strictures using tandem stents.

PURPOSE: To evaluate outcomes of primary (first-occurrence) treatment of renal transplant ureteral strictures using tandem parallel internal double-pigtail stents. MATERIALS AND METHODS: A retrospective electronic chart review, including demographics, medical history, stricture intervention, and outcomes, was performed of patients with renal transplants with first-occurrence ureteral obstructions or leaks reported in a transplant nephrology database over a 4-year period, with a focus on patients treated primarily with tandem stents. RESULTS: Of 27 patients with first-occurrence ureteral obstruction or ureteral leak, 18 (67%) were treated primarily using tandem internal stents, with 15 (83%) of 18 stent-free for a minimum 90 days of follow-up. There was no significant difference between outcomes for male versus female patients (P>.99) or early versus late strictures (P = .53). Urinary tract infections (UTIs) occurred in 14 (78%) of 18 patients with tandem stents in place. Four patients were hospitalized<48 hours with UTI and sepsis; there were no other major complications. CONCLUSIONS: Patients with renal transplants can be successfully managed nonsurgically using tandem ureteral stents for the primary treatment of first-occurrence ureteral stricture. These patients may require more intensive monitoring for UTIs.

Performance of an algorithm for diagnosing acute cholecystitis using clinical and sonographic parameters.

PURPOSE: Identify an algorithm using clinical and ultrasound (US) parameters with high diagnostic performance for acute cholecystitis. METHODS: Consecutive emergency department (ED) patients from 4/1/2019 to 12/31/2019 were retrospectively reviewed to record non-US parameters and make US observations. Outcomes were categorized as either: (1) acute cholecystitis; or (2) negative acute cholecystitis. Pivot tables identified parameter combinations either not found with acute cholecystitis or with predictive value for acute cholecystitis to establish the algorithm. US Division radiologists finalized an US report prior to ED disposition without use of the algorithm. Radiologist impression and algorithm prediction for acute cholecystitis were categorized as either (1) acute cholecystitis; (2) negative acute cholecystitis; or (3) inconclusive. RESULTS: Three hundred and sixty-six studies on 357 patients (mean age, 51 yrs ± 20 yrs; 215 women) met the inclusion criteria. 10.9% (40/366) of US studies had acute cholecystitis, 12.6% (46/366) had pathologically identified chronic cholecystitis without acute cholecystitis, and 76.5% (280/366) were negative acute cholecystitis. Algorithm compared to radiologist diagnostic performance was as follows: (1) sensitivity: 90.0% vs. 55.0%, p < 0.001; (2) augmented sensitivity (defined as when inconclusive categorization is considered consistent with acute cholecystitis): 100% vs. 85.0%, p < 0.001; (3) specificity: 93.6% vs. 94.8%, p = 0.50; (4) diagnostic rate (opposite of inconclusive rate): 96.4% vs. 93.2%, p = 0.04; (5) adverse outcome rate: 0.0% vs. 1.6%, p undefined. CONCLUSION: For acute cholecystitis, an algorithm using non-binary ultrasound and clinical assessments had higher sensitivity, higher diagnostic rate, and fewer adverse outcomes, than subspecialty radiologist impressions.

The impact of blood pressure on the risk of major bleeding complication after renal transplant biopsy.

PURPOSE: To assess the impact of elevated blood pressure on the rate of major hemorrhagic complication after renal transplant biopsy. METHODS: Pre-procedural systolic (SBP), diastolic (SBP), and mean arterial (MAP) blood pressure for consecutive patients undergoing US-guided renal transplant biopsies from 08/01/2015 to 7/31/2017 were retrospectively recorded. Patients who had a major bleeding complication were identified. The risk of complication as a function of SBP, DBP, and MAP was statistically analyzed, with significance set at p < 0.05. RESULTS: Of 1689 biopsies, there were 10 bleeding complications (10/1689, 0.59%). There was no statistically significant difference between biopsies with complication compared to those without complication based on SBP (p = 0.351), DBP (p = 0.088), or MAP (p = 0.132). Using risk dichotomization criteria, the odds ratio for hemorrhagic complication when the patient had SBP ≥ 180 mmHg and DBP ≥ 95 mmHg was 75.63 (95% CI 6.87-516.8, p = 0.002). CONCLUSION: The rate of hemorrhagic complication from renal transplant biopsy is low, and there is no statistically significant threshold for increased biopsy risk based on SBP, DBP, or MAP alone. The risk of complication was significantly higher only when both the SBP is ≥ 180 mmHg and DBP is ≥ 95 mmHg.

Ultrasound-Guided Phrenic Nerve Block for Lung Nodule Biopsy: Single-Center Initial Experience.

RATIONALE AND OBJECTIVES: Biopsy of lung nodules in the lower lung fields can be difficult because of breathing motion. Ipsilateral phrenic nerve block (PNB) before biopsy should make the biopsy safer, easier, and more precisely targeted. We describe the use of ultrasound-guided PNB before lung nodule biopsy, including relevant anatomy and variations, complications, and technique, along with our first 40 cases. MATERIALS AND METHODS: We retrospectively reviewed patients who underwent PNB before computed tomography (CT)- or ultrasound-guided lung nodule biopsy from April 2015 through March 2020. Patient demographics, CT fluoroscopy time, radiation dose, complications, diagnostic yield, and effectiveness of PNB were recorded. Effectiveness of PNB was based on direct observation of diaphragmatic motion. Control group data for biopsies during the same time frame were collected and matched with nodules ≤1 cm from the PNB group. RESULTS: Among 40 patients identified, no complications occurred related to the PNB. Mean (SD) nodule size was 12.4 (6.2) mm. True-positive results were obtained in 39 patients (98%), with 1 false-negative after an ineffective PNB. PNB was effective in 70%. When CT fluoroscopy was used for the biopsy, radiation dose was significantly lower after an effective PNB than an ineffective PNB (p < .001). Effective PNB was significantly more common with injection of ≥4 mL of local anesthetic (p = .01). Comparison with 19 matched controls showed significantly fewer instances of pneumothorax (p = .02) and greater diagnostic success (p = .03) for the PNB group. CONCLUSION: Ultrasound-guided PNB is safe and effective and can improve outcomes when used before lung nodule biopsy.

Partial preparation computed tomographic colonography: a feasibility study.

We retrospectively evaluated computed tomographic colonography examinations of patients who have had a partial bowel preparation and compared the quality of their preparation with patients who have had a full bowel preparation. In total, 27 patients undergoing computed tomographic colonography examination (10 patients with partial bowel preparation and 17 with full bowel preparation) had their examinations retrospectively reviewed by three independent radiologists in a blinded manner, with evaluation of residual stool, distention, residual fluid, and overall bowel preparation quality. Six colon segments were evaluated individually and independently for these four variables (a total of 161 segments tested). Comparisons were made with the Mann-Whitney test between the partial preparation group and the full preparation group. Partial preparation included stool and fluid tagging plus 20 mg of bisacodyl orally; full preparation included stool and fluid tagging plus 2 L of polyethylene glycol solution. No significant clinical difference was found in colon preparation between the partial and full bowel preparation groups--when evaluated with individual colon segments or by independent readers. Interreader correlation was high. This pilot study indicates that full bowel preparation is not required for diagnostic-quality computed tomographic colonography examination. Further evaluation of this partial bowel preparation regimen is warranted.

Single-Center Review of Celiac Plexus/Retrocrural Splanchnic Nerve Block for Non-Cancer Related Pain.

RATIONALE AND OBJECTIVES: Celiac plexus and retrocrural splanchnic nerve (CP/RSN) blocks are widely used for cancer-related abdominal pain, but there is limited literature on their efficacy for non-cancer related pain. Our aim was to determine the indications and effectiveness of CT-guided CP/RSN blocks performed on patients with abdominal pain from non-cancer related sources. MATERIALS AND METHODS: CT-guided CP/RSN blocks for non-cancer related abdominal pain from 2011-2020 were retrospectively reviewed for patient demographics, procedure details, duration of pain relief, and complications. Effective blocks were defined as patient-reported pain relief or decrease in opioid use lasting 2 or more days for temporary blocks and 14 or more days for permanent blocks. RESULTS: Of 72 CT-guided CP/RSN blocks for non-cancer related abdominal pain, 48 (67%) were effective for a mean of 51 days (median 14, range 2-700). Of the 18 permanent blocks, 9 (50%) were effective for a mean of 111 days (median 90, range 14-390). Of the 54 temporary blocks, 39 (72%) were effective for a mean of 37 days (median 9, range 2-700). Indications included postural orthostatic tachycardia syndrome/dysautonomia (77% effective, 20/26), pancreatitis (86% effective, 12/14), postsurgical pain (62% effective, 8/13), median arcuate ligament syndrome (70% effective, 7/10), chronic pain syndrome (20% effective, 1/5), gastroparesis (80% effective, 4/5), and renal cystic disease (33% effective, 1/3). For postural orthostatic tachycardia syndrome /dysautonomia, pancreatitis, post-surgical pain, and MALS, there were no statistically significant differences in effectiveness between celiac vs. splanchnic blocks in groups matched by indication and intended duration (temporary/permanent). CONCLUSIONS: CT-guided CP/RSN blocks can effectively manage non-cancer related abdominal pain, though there is discrepancy in efficacy between temporary and permanent blocks.

US-guided renal transplant biopsy: efficacy of a cortical tangential approach.

PURPOSE: To describe the cortical tangential approach to ultrasonographically (US) guided renal transplant biopsy and evaluate its efficacy in obtaining sufficient cortical tissue. MATERIALS AND METHODS: This HIPAA-compliant retrospective study was exempted from review by the institutional review board. Informed consent was not required. The number of core biopsy samples, glomeruli, and small arteries obtained during 294 consecutive US-guided renal transplant biopsies in 254 patients (134 men, 120 women; age range, 19-79 years; mean age, 52.2 years) in one department between June 1 and December 31, 2008, were recorded, along with any ensuing complications. Procedural success was assessed according to Banff 97 criteria. RESULTS: There were 1.2 +/- 0.4 (standard deviation) biopsy core samples taken per case by 11 radiologists using the cortical tangential approach. In 290 cases, biopsy results showed 21.7 +/- 10.1 glomeruli and 5.0 +/- 2.8 small arteries. Two hundred seventy-six (95%) cases were adequate or minimal according to Banff 97 assessment criteria. Of the 14 inadequate cases (5%), six were lacking only one glomerulus to achieve minimal status. Only one biopsy core sample was taken in all 14 inadequate cases and in 233 successful cases (success rate, 85%). None of the 43 cases with two or more biopsy core samples taken were inadequate (success rate, 100%). Two patients (0.7%) had a hemorrhagic complication requiring transfusion, and another four patients (1.4%) experienced a minor self-limiting complication. CONCLUSION: The cortical tangential approach can be used by a cohort of radiologists to achieve 95% or higher collective success in obtaining cortical tissue during renal transplant biopsy, with few complications. The success rate is higher, without increased complications, when more than one core specimen is taken.

CT-guided biopsy of perivascular tumor encasement using simultaneous IV contrast enhancement.

OBJECTIVE: The purpose of our study was to describe and review the accuracy of a novel technique for difficult biopsy of arterial tumor encasement using simultaneous IV contrast enhancement and helical CT guidance for coaxial core needle biopsies. CONCLUSION: Diagnostic biopsy specimens can be obtained safely using simultaneous IV contrast-enhanced CT guidance during difficult biopsies of unresectable tumors encasing the celiac, superior mesenteric, or left renal arteries.