Smoking Significantly Impacts Persistence Rates in Embolized Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia.

Background Embolization is the standard of care for treatment of pulmonary arteriovenous malformations (PAVMs). Persistence of PAVMs after embolization occurs for undefined reasons but may include inflammation related to smoking in dysregulated angiogenesis. Purpose To determine whether patients with hereditary hemorrhagic telangiectasia (HHT) who smoke tobacco are more prone to PAVM persistence after embolization. Materials and Methods Patients with HHT treated for PAVMs between January 2000 and August 2017 were retrospectively identified. Only PAVMs with no previous treatment and patients with both clinical and imaging follow-up were included. Age, sex, PAVM characteristics (size, complexity, and location), embolization material used, microcatheter type, smoking history, active tobacco use, and other risk factors for arterial disease were analyzed by using a multivariate Cox proportional hazards model to determine risk factors for persistence. Results Five-year persistence-free survival rates in nonsmokers, smokers of 1-20 pack-years, and smokers of more than 20 pack-years were 12.2%, 21.9%, and 37.4% respectively. Smokers with more than 20 pack-years relative to nonsmokers had greater risk of persistence after adjusting for arterial feeder size (hazard ratio, 3.8; 95% confidence interval [CI]: 1.5, 10.0; P = .007). Patients who reported active tobacco use at the time of PAVM embolization had a 5-year cumulative incidence of persistence of 26.3% compared with 13.5% in inactive smokers. After adjusting for arterial feeder size, the risk of persistence was greater in tobacco users versus inactive smokers at the time of treatment (hazard ratio, 2.4; 95% CI: 1.2, 4.7; P = .01). Conclusion Smoking is associated with pulmonary arteriovenous malformation persistence after embolization in patients with hereditary hemorrhagic telangiectasia. Online supplemental material is available for this article. See also the editorial by Trerotola and Pyeritz in this issue.

Comparison of Bleeding Complications between Transplenic versus Transhepatic Access of the Portal Venous System.

PURPOSE: To evaluate the incidence of bleeding complications between transplenic (TS) and transhepatic (TH) access in portal venous interventions. MATERIALS AND METHODS: Retrospective review of patients who underwent TS or TH access for portal venous system interventions from January 2000 to August 2017. Only procedures with clinical and laboratory follow-up were included (n = 148). Twenty-four TS procedures were performed in 22 patients, and 124 TH procedures were performed in 114 patients. The main indications were for angioplasty/stent, embolization of varices/shunt, or portal vein embolization, with no difference between the groups. Mean patient age and sex were not significantly different between the groups (P values .445 and .682, respectively). Mean follow up was 2.3 years (range 0.1-14.2). There was no significant difference between the international normalized ratio (P = .300) and platelets (P = .234) before the procedure between the 2 cohorts. RESULTS: Technical success of vascular access and procedural success was achieved in 22/24 (91.6%) TS procedures and 120/124 (96.8%) TH procedures (P = .238). There was no significant difference in bleeding complications between the 2 groups (3/24 [12.5%] TS vs 10/124 [8.1%] TH; P = .44). There was no significant difference in major bleeding complications (SIR classification ≥ C; 1/24 [4.2%] TS vs 4/124 [3.2%] TH; P = .789).There was no significant difference in the hemoglobin before or after the procedure (g/dL), with average change -1.1 g/dL (range -3.4 to +1.0) in the TS group and 1.0 g/dL (range -4.5 to +1.9) in the TH group (P = .540). Finally, there was no significant difference in proportion of patients requiring blood transfusion after the procedure (P = .520), with 2 (8.3%) in the TS group requiring an average of 4 units (range 2-6) and 17 (13.7%) in the TH group requiring an average of 3.5 units (range 1-26). CONCLUSIONS: These data suggest no significant difference in bleeding complications between TS and TH access for portal venous interventions.

Percutaneous Cryoablation of Solitary, Sporadic Renal Cell Carcinoma: Outcome Analysis Based on Clear-Cell versus Papillary Subtypes.

PURPOSE: To evaluate treatment outcomes with percutaneous cryoablation (PCA) based on renal cell carcinoma (RCC) histology. METHODS AND MATERIALS: Patients treated with PCA for a solitary, sporadic stage T1a RCC from 2003 to 2016 were identified from a single institution's renal ablation registry. Patients with multiple tumors, history of RCC, or genetic syndromes associated with RCC (n = 60); no specific RCC subtype determined from core biopsy (n = 66); RCC subtype other than clear-cell or papillary (n = 7); or less than 3 mo of follow-up imaging (n = 5) were excluded. In total, 173 patients met study inclusion criteria. Oncologic outcomes, clinical outcomes, and complications were evaluated based on tumor subtype. RESULTS: Of the 173 patients who underwent PCA for a stage T1a RCC, 130 (75%) had clear-cell RCC (ccRCC) and 43 (25%) had papillary RCC (pRCC). Median tumor size was 2.9 cm (range, 1.3-4.0 cm). Technically successful cryoablation was achieved in all 173 patients. Local tumor recurrence developed in 6 patients with ccRCC (4.6%), new renal tumors developed in 1 patient (0.8%), and metastatic RCC developed in 1 patient (0.8%) who also had local tumor recurrence. No patients with pRCC showed local tumor recurrence, new renal tumors, or metastatic disease. The 5-year disease-free survival rate in patients with ccRCC was 88%, compared with 100% in patients with pRCC (P = .48). Nine patients (5.2%), all with ccRCC, experienced major complications (P = .11). CONCLUSIONS: Percutaneous ablation is a viable treatment option for patients with clinical stage T1a pRCC and ccRCC. Percutaneous ablation may be a very favorable treatment strategy particularly for pRCC.

Is Long-Term Anticoagulation Required after Stent Placement for Benign Superior Vena Cava Syndrome?

PURPOSE: To identify whether symptom relief and stent patency vary with use of long-term anticoagulation after stent placement for benign superior vena cava (SVC) syndrome. MATERIALS AND METHODS: Patients with benign SVC syndrome treated with stent placement between January 1999 and July 2017 were retrospectively identified (n = 58). Average age was 49 years (range, 24-80 y); 34 (58%) were women, and 24 (42%) were men. Average follow-up was 2.4 years (range, 0.1-11.1 y, SD 2.6). Of cases, 37 (64%) were due to a long-term line/pacemaker, and 21 (36%) were due to fibrosing mediastinitis. After stent placement, 36 (62%) patients were placed on long-term anticoagulation, and 22 (38%) were not placed on anticoagulation. Percent stenosis was evaluated on follow-up imaging by dividing smallest diameter of the stent by a normal nonstenotic segment of the stent and multiplying by 100. RESULTS: Technical success was achieved in all cases. There was no significant difference in number of patients who reported a return of symptoms characteristic of benign SVC syndrome between the anticoagulated (16 of 36; 44.4%) and nonanticoagulated (11 of 22; 50%) groups (P = .68). There was no significant difference in the mean percent stenosis between the anticoagulated (40.4% ± 34.7% [range, 0-100%]) and nonanticoagulated (32.1% ± 29.2% [range, 1.7%-100%]) groups (P = .36). No significant difference was found in the time (days) between date of procedure and date of return of symptoms (anticoagulated, 735.9 d ± 1,003.1 [range, 23-3,851 d]; nonanticoagulated, 478 d ± 826.6 [range, 28-2,922 d]) (P = .49). There was no difference in primary patency between groups (P = .59). Finally, 1 patient (2.8%) in the anticoagulated group required surgical intervention, whereas none in the nonanticoagulated group required surgical intervention. CONCLUSIONS: No significant difference was observed in clinical and treatment outcomes in patients who did and did not receive anticoagulation after stent placement for benign SVC syndrome. Management of benign SVC syndrome after stent placement may not require anticoagulation if confirmed by additional studies.

Comprehensive assessment of renal tumour complexity in a large percutaneous cryoablation cohort.

OBJECTIVE: To evaluate the association between renal tumour complexity and outcomes in a large cohort of patients undergoing percutaneous cryoablation (PCA). PATIENTS AND METHODS: Patients with renal tumours treated with PCA were identified using our prospectively maintained ablation registry (2003-2015). Salvage procedures and inherited tumour syndromes were excluded. The associations between R.E.N.A.L. nephrometry score (NS) and risk of complications, renal function impairment, local failure and cancer-specific mortality (CSM) were evaluated using univariate and multivariable logistic, linear and Cox regression models. RESULTS: The cohort included 618 tumours treated during 580 procedures in 565 patients. The median (interquartile range [IQR]) follow-up was 34 (14.66) months. Complications (any grade) during a procedure (n[total] = 87, 15%) were more frequent with higher NS (NS 4-6: 10%; NS 7-9: 14%; NS 10-12: 36%; P < 0.001). Higher NS was independently associated with risk of complications (odds ratio [OR; per 1 point] = 1.3; 95% confidence interval [CI] 1.2-1.5; P < 0.001). Of all the NS components, tumour size was the most strongly associated with complication risk (OR 3.4; 95% CI 2.2-5.2; P < 0.001). The median (IQR) decline in glomerular filtration rate (GFR) from baseline was 9% (0, 22) at last follow-up. Each additional point in NS was associated with a 1.3% (95% CI 0.4-2.1; P = 0.005) greater GFR decline from baseline. NS was not significantly associated with local failure (n [total] = 14, 2%; NS 4-6: 2%; NS 7-9: 3%; NS 10-12: 5%; P = 0.32) or CSM (n [total] = 8, 2%; NS 4-6: 2%; NS 7-9: 3%; NS 10-12: 2%; P = 0.88). CONCLUSION: In high-complexity tumours PCA was associated with a tumour size-driven increased risk of post-procedural complications. Higher NS was associated with a small, clinically minor additional decline in renal function. Risks for local failure and CSM were low, regardless of tumour complexity.

Comparison of Covered Versus Uncovered Stents for Benign Superior Vena Cava (SVC) Obstruction.

PURPOSE: To identify whether long-term symptom relief and stent patency vary with the use of covered versus uncovered stents for the treatment of benign SVC obstruction. METHODS AND MATERIALS: We retrospectively identified all patients with benign SVC syndrome treated to stent placement between January 2003 and December 2015 (n = 59). Only cases with both clinical and imaging follow-up were included (n = 47). In 33 (70%) of the patients, the obstruction was due to a central line or pacemaker wires, and in 14 (30%), the cause was fibrosing mediastinitis. Covered stents were placed in 17 (36%) of the patients, and 30 (64%) patients had an uncovered stent. Clinical and treatment outcomes, complications, and the percent stenosis of each stent were evaluated. RESULTS: Technical success was achieved in all cases at first attempt. Average clinical and imaging follow-up in years was 2.7 (range 0.1-11.1) (covered) and 1.7 (range 0.2-10.5) (uncovered), respectively. There was a significant difference (p = 0.044) in the number of patients who reported a return of symptoms between the covered (5/17 or 29.4%) and uncovered (18/30 or 60%) groups. There was also a significant difference (p = < 0.001) in the mean percent stenosis after stent placement between the covered [17.9% (range 0-100) ± 26.2] and uncovered [48.3% (range 6.8-100) ± 33.5] groups. No significant difference (p = 0.227) was found in the time (days) between the date of the procedure and the date of clinical follow-up where a return of symptoms was reported [covered: 426.6 (range 28-1554) ± 633.9 and uncovered 778.1 (range 23-3851) ± 1066.8]. One patient in the uncovered group had non-endovascular surgical intervention (innominate to right atrial bypass), while none in the covered group required surgical intervention. One major complication (SIR grade C) occurred that consisted of a pericardial hemorrhagic effusion after angioplasty that required covered stent placement. There were no procedure-related deaths. CONCLUSION: Both covered and uncovered stents can be used for treating benign SVC syndrome. Covered stents, however, may be a more effective option at providing symptom relief and maintaining stent patency if validated by further studies.

Outcomes After Cryoablation Versus Partial Nephrectomy for Sporadic Renal Tumors in a Solitary Kidney: A Propensity Score Analysis.

BACKGROUND: While partial nephrectomy (PN) is considered the standard approach for a tumor in a solitary kidney, percutaneous cryoablation (PCA) is emerging as an alternative nephron-sparing option. OBJECTIVE: To compare outcomes between PCA and PN for tumors in a solitary kidney. DESIGN, SETTING, AND PARTICIPANTS: Patients who underwent PCA or PN between 2005 and 2015 for a single primary renal tumor in a solitary kidney were identified using Mayo Clinic Registries. Exclusion criteria were inherited tumor syndromes and salvage procedures. INTERVENTION: PCA and PN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: To achieve balance in baseline characteristics, we used inverse probability of treatment weighting (IPTW) based on propensity to receive treatment. The risk of having a post-treatment complication and percent drop in estimated glomerular filtration rate (eGFR), as well as the risks of local/ipsilateral recurrence, distant metastasis, and cancer-specific mortality, were compared between groups using logistic, linear, and Fine-and-Gray competing risk regression models. RESULTS AND LIMITATIONS: The cohort included 118 patients (PCA: 54; PN: 64) with a median follow-up of 47 mo (interquartile range 18, 74). In unadjusted analyses, PCA was associated with a lower risk of complications (15% vs 31%; odds ratio [OR]=0.38; 95% confidence interval [CI] 0.15, 0.96; p=0.04). However, upon accounting for baseline differences with IPTW adjustment, there was no longer a significant difference in the risk of complications (28% vs 29%; OR=0.95; 95% CI 0.53, 1.69; p=0.9). There were no significant differences between PCA and PN in percentage drop in eGFR at discharge (mean: 11% vs 16%; ß=-5%; 95% CI -13, 3; p=0.2) or at 3 mo (12% vs 9%; ß=3%; 95% CI -3, 10; p=0.3). Likewise, no significant differences were noted in local recurrence (HR=0.87; 95% CI 0.38, 1.98; p=0.7), distant metastases (HR=0.60; 95% CI 0.30, 1.20; p=0.2), or cancer-specific mortality (HR=1.13; 95% CI 0.32, 3.98; p=0.8). Limitations include the sample size, given the relative rarity of renal masses in solitary kidneys. CONCLUSIONS: Our study found no significant difference in complications, renal function outcomes, and oncologic outcomes between PN and PCA for patients with a tumor in a solitary kidney. Validation in a larger multi-institutional analysis may be warranted. PATIENT SUMMARY: Partial nephrectomy (surgery) and percutaneous cryoablation are both options for treating a kidney tumor while preserving the normal portion of the kidney. In patients with a tumor in their only kidney, we found no difference in the risk of complications, kidney function outcomes, or cancer control outcomes between these two approaches.

Stereotactic body radiation therapy of liver tumors: post-treatment appearances and evaluation of treatment response: a pictorial review.

Stereotactic body radiation therapy (SBRT) is a noninvasive treatment technique for selected patients with primary liver tumors and liver-confined oligometastatic disease. Recently, SBRT has emerged as an alternative treatment option in non-surgical candidates and in whom percutaneous treatment methods are not possible or contraindicated. The experience with SBRT continues to grow. There are currently no imaging guidelines for assessment of tumor response and follow-up schedule following SBRT. SBRT produces characteristic radiation-induced changes in the treated tumor and surrounding liver parenchyma. Knowledge of these changes is essential in the interpretation of follow-up imaging and assessment of treatment response. In this review, we will describe the CT, MRI, and PET imaging findings following SBRT of both the targeted liver tumor and surrounding hepatic parenchyma.