Rules for Interventional Radiology.

During the hands-on teaching of Interventional Radiology (IR) to Residents and Fellows, certain learning tips or guiding statements are often repeated. Over the past two decades, these tips have evolved into the "Rules for Interventional Radiology." Relying on humour and the technical and foundational principles of our subspeciality, it is hoped that these Rules for IR provide helpful guidance to learners and practising Interventionalists in their daily work.

Uterine Artery Embolization for Pedunculated Subserosal Fibroids: A Systematic Review and Meta-Analysis.

PURPOSE: To provide a comprehensive overview of the literature assessing the safety and efficacy of uterine artery embolization (UAE) for patients with pedunculated subserosal fibroids. MATERIALS AND METHODS: MEDLINE and Embase databases were searched without language or publication type restrictions for observational studies to estimate safety (adverse events) and efficacy (devascularization, fibroid volume reduction, and uterine volume reduction) outcomes. Case reports were included to qualitatively report adverse events. Meta-analysis was performed for single proportions and mean changes with random-effects modeling. RESULTS: Of 98 eligible articles, 11 studies were included in the final analysis. Of the adverse events detailed in these cases, 5 events were mild, 2 were moderate (torsion of pedunculated fibroid requiring laparoscopic myomectomy and persistent bleeding after embolization requiring hysterectomy), and 1 was severe (fibroid necrosis causing bowel obstruction requiring bowel resection and hysterectomy). There were no deaths reported in the literature. The pooled risk of adverse events was 1.7% (95% confidence interval [CI], 0.29%-9.2%; 4 of 181; I2 = 0%). The pooled devascularization rate was 75.9% (95% CI, 62.4%-85.6%; 140 of 189; I2 = 75%) at 3.91 months of follow-up. The percent volume reduction of the dominant pedunculated fibroid was 38.6% (95% CI, 33.0%-44.2%; I2 = 0%) at 4.3 months of follow-up. The percent uterine volume reduction was 36.7% (95% CI, 30.3%-43.0%; I2 = 47%) at 3.5 months of follow-up. CONCLUSIONS: UAE for pedunculated subserosal fibroids has a low risk of adverse events and effectively reduces fibroid and uterine size.

Safety of High-Dose 3% Sodium Tetradecyl Sulfate for Sclerotherapy of Renal Cysts in Patients with Autosomal Dominant Polycystic Kidney Disease.

This study assessed the safety profile of high-volume (>10 mL) 3% sodium tetradecyl sulfate (STS) sclerotherapy for the treatment of renal cysts in patients with autosomal dominant polycystic kidney disease. A total of 211 sclerotherapy treatments were performed in 169 patients over a 5-year period, with a comparison of 2 patient cohorts based on the STS volumes used. The first cohort (n = 112) received a high volume (greater than 10 mL) of STS, and the second cohort (n = 57) received a low volume (less than 10 mL). The minor adverse event rate for the cohorts was 14.5% and 9.6%, respectively (P = .310), with postprocedure pain being the most common event. One major adverse event occurred, for which the patient required hospitalization for infection after low-volume STS treatment. Doses of STS higher than those currently recommended by the Food and Drug Administration for intravascular use allow large renal cysts to be treated safely in the setting of autosomal dominant polycystic kidney disease.

Overall Impact of the COVID-19 Pandemic on Interventional Radiology Services: A Canadian Perspective.

PURPOSE: The aim of this national survey was to assess the overall impact of the coronavirus disease 2019 (COVID-19) pandemic on the provision of interventional radiology (IR) services in Canada. METHODS: An anonymous electronic survey was distributed via national and regional radiology societies, exploring (1) center information and staffing, (2) acute and on-call IR services, (3) elective IR services, (4) IR clinics, (5) multidisciplinary rounds, (6) IR training, (7) personal protection equipment (PPE), and departmental logistics. RESULTS: Individual responses were received from 142 interventional radiologists across Canada (estimated 70% response rate). Nearly half of the participants (49.3%) reported an overall decrease in demand for acute IR services; on-call services were maintained at centers that routinely provide these services (99%). The majority of respondents (73.2%) were performing inpatient IR procedures at the bedside where possible. Most participants (88%) reported an overall decrease in elective IR services. Interventional radiology clinics and multidisciplinary rounds were predominately transitioned to virtual platforms. The vast majority of participants (93.7%) reported their center had disseminated an IR specific PPE policy; 73% reported a decrease in case volume for trainees by at least 25% and a proportion of trainees will either have a delay in starting their careers as IR attendings (24%) or fellowship training (35%). CONCLUSION: The COVID-19 pandemic has had a profound impact on IR services in Canada, particularly for elective cases. Many centers have utilized virtual platforms to provide multidisciplinary meetings, IR clinics, and training. Guidelines should be followed to ensure patient and staff safety while resuming IR services.

Clinical IR in Canada: The Evolution of a Revolution.

PURPOSE: To investigate the current status and evolution of both the interventional radiologist's role as a clinician and the practice of interventional radiology (IR) over the past decade in Canada. MATERIALS AND METHODS: In 2015, an online survey was e-mailed to 210 interventional radiologists, including all Canadian active members of the Canadian Interventional Radiology Association (CIRA) and nonmembers who attended CIRA's annual meeting. Comparisons were made between interventional radiologists in academic versus community practice. The results of the 2015 survey were compared with CIRA's national surveys from 2005 and 2010. RESULTS: A total of 102 interventional radiologists responded (response rate 49%). Significantly more academic versus community interventional radiologists performed chemoembolization, transjugular intrahepatic portosystemic shunt, aortic interventions, and arteriovenous malformation embolization (P < .05). Ninety percent of respondents were involved in longitudinal patient care, which had increased by 42% compared with 2005; 46% of interventional radiologists had overnight admitting privileges, compared with 39% in 2010 and 29% in 2005. Eighty-six percent of interventional radiologists accepted direct referrals from family physicians, and 83% directly referred patients to other consultants. Sixty-three percent participated in multidisciplinary tumor board. The main challenges facing interventional radiologists included a lack of infrastructure, inadequate remuneration for IR procedures, and inadequate funding for IR equipment. Significantly more community versus academic interventional radiologists perceived work volume as an important issue facing the specialty in 2015 (60% vs 34%; P = .02). CONCLUSIONS: Over the past decade, many Canadian interventional radiologists have embraced the interventional radiologist-clinician role. However, a lack of infrastructure and funding continue to impede more widespread adoption of clinical IR practice.

Radiofrequency Ablation of T1a Renal Cell Carcinomas within Renal Transplant Allografts: Oncologic Outcomes and Graft Viability.

PURPOSE: To evaluate oncologic outcomes and graft viability after percutaneous radiofrequency (RF) ablation of renal cell carcinoma (RCC) developing within renal transplant allografts. MATERIALS AND METHODS: A single-institution, retrospective study reviewed all patients treated with RF ablation for RCC between February 2004 and May 2016. Ten patients were identified (age 49.6 y ± 12.6; 9 men, 1 woman) with 12 biopsy-confirmed RCC tumors within the allograft (all T1a, mean diameter 2.0 cm ± 0.7). Mean time from transplant to RCC diagnosis was 13.2 years ± 6.3. RF ablation was performed on an outpatient basis using conscious sedation. Procedural efficacy, complications, oncologic outcomes, and allograft function were evaluated. Statistical analysis with t tests and Pearson correlation compared allograft function before and after RF ablation and impact of proportional ablation size to allograft volume on function after ablation. RESULTS: Technical success rate and primary technique efficacy were 100% (12/12). No local or distant RCC progression was seen at mean follow-up of 54.3 months ± 38.7 (range, 9-136 months). Graft failure requiring hemodialysis or repeat transplantation occurred in 3 patients (26, 354, and 750 d after RF ablation), all of whom had glomerular filtration rate (GFR) < 30 mL/min/1.73 m2 before ablation. For all patients, mean GFR 6 months after RF ablation (35.8 mL/min/1.73 m2 ± 17.7) was not significantly different (P = .8) from preprocedure GFR (36.2 mL/min/1.73 m2 ± 14.3). Proportional volume of allograft that was ablated did not correlate with immediate or long-term GFR changes. One patient died of unrelated comorbidities 52 months after ablation. No major complications occurred. CONCLUSIONS: RF ablation of renal allograft RCC provided effective oncologic control without adverse impact on graft viability.

Thermal Ablation versus Surgical Resection for the Treatment of Stage T1 Hepatocellular Carcinoma in the Surveillance, Epidemiology, and End Results Database Population.

PURPOSE: To compare survival outcomes of small solitary hepatocellular carcinomas (HCCs) treated with thermal ablation vs resection in the Surveillance, Epidemiology, and End Results (SEER) cohort. MATERIALS AND METHODS: SEER data (November 2014 submission) were searched for histologic diagnoses of HCC and stage T1 disease (≤ 5-cm solitary tumor without vascular invasion). Comparison was made between thermal ablation and resection as the primary treatment. Overall and disease-specific survival were compared by log-rank tests (stratified for presence of fibrosis) and Cox regression (with tumor size and presence of fibrosis covariates). RESULTS: Of 264 patients with ≤ 2-cm HCCs, 185 underwent thermal ablation and 79 underwent resection. Patients undergoing ablation had higher Ishak scores (P = .0002). There was no difference in survival (observed P = .698, disease-specific P = .446). Of 544 patients with 2.1-4-cm HCCs, 335 underwent thermal ablation and 209 underwent resection. Patients undergoing ablation were more likely to have higher Ishak scores (P < .001), but had slightly smaller tumors (2.9 vs 3.1 cm; P < .001). There was no difference in survival (observed P = .174, disease-specific P = .609). Of 112 patients with 4.1-5-cm HCCs, 46 underwent thermal ablation and 66 underwent resection. Patients undergoing ablation had higher Ishak scores (P = .0002). Surgical resection was associated with improved survival (observed P = .009, disease-specific P = .046). CONCLUSIONS: There was no difference in overall or disease-specific survival between surgical resection and thermal ablation for T1 HCCs ≤ 4 cm after adjusting for the presence of histologic fibrosis and tumor size in the SEER cohort. Significant benefit was observed with surgery for tumors measuring 4.1-5 cm.

Comparison of Clinical Outcomes following Glue versus Polyvinyl Alcohol Portal Vein Embolization for Hypertrophy of the Future Liver Remnant prior to Right Hepatectomy.

PURPOSE: To report outcomes after portal vein embolization (PVE) and right hepatectomy in patients receiving embolization with N-butyl cyanoacrylate (NBCA) glue + central AMPLATZER Vascular Plug (AVP; glue group) or polyvinyl alcohol (PVA) particles ± coils (PVA group). MATERIALS AND METHODS: Between March 2008 and August 2013, all patients having PVE with NBCA + AVP or PVA ± coils before right hepatectomy were retrospectively reviewed; 85 patients underwent PVE with NBCA + AVP (n = 45) or PVA ± coils (n = 40). The groups were compared using Mann-Whitney U and χ2 tests. RESULTS: Technical success of embolization was 100%. Degree of hypertrophy (16.2% ± 7.8 vs 12.3% ± 7.62, P = .009) and kinetic growth rate (3.5%/wk ± 2.0 vs 2.6%/wk ± 1.9, P = .016) were greater in the glue group versus the PVA group. Contrast volume (66.1 mL ± 44.8 vs 189.87 mL ± 62.6, P < .001) and fluoroscopy time (11.2 min ± 7.8 vs 23.49 min ± 11.7, P < .001) were significantly less during the PVE procedure in the glue group. Surgical outcomes were comparable between groups, including the number of patients unable to go onto surgery (P = 1.0), surgical complications (P = .30), length of hospital stay (P = .68), and intensive care unit admissions (P = .71). There was 1 major complication (hepatic abscess) in each group after PVE. CONCLUSIONS: PVE performed with NBCA + AVP compared with PVA ± coils resulted in greater degree of hypertrophy of the future liver remnant, less fluoroscopic time and contrast volume, and similar complication rates.

Randomized Trial Comparing Radiologic Pigtail Gastrostomy and Peroral Image-Guided Gastrostomy: Intra- and Postprocedural Pain, Radiation Exposure, Complications, and Quality of Life.

PURPOSE: To prospectively compare radiologically created pigtail gastrostomy (PG), in which the tube is inserted directly through the abdominal wall, versus peroral image-guided gastrostomy (POG), in which the tube is inserted through the mouth. Pain profiles (primary outcome measure), fluoroscopy times, total room times, technical success, complications, and quality of life (QOL) were measured. MATERIALS AND METHODS: Sixty patients were prospectively randomized to receive 14-F PG or 20-F POG tubes. All patients received prophylactically created gastrostomies before radiation therapy for head and neck squamous-cell carcinoma. Patients receiving palliative treatment were excluded, as were those with established pharyngeal obstruction. Pain was measured by numeric rating scale (NRS) scores for 6 weeks after the procedure and by intraprocedural fentanyl and midazolam doses and postprocedural 24-h morphine doses. Fluoroscopy times, total room times, technical success, complications up to 6 months, and gastrostomy-related QOL (using the Functional Assessment of Cancer Therapy-Enteral Feeding questionnaire) were determined. RESULTS: Fifty-six patients underwent the randomized procedure. The POG group required significantly higher intraprocedural midazolam and fentanyl doses (mean, 1.2 mg and 67 µg, respectively, for PG vs 1.9 mg and 105 µg for POG; P < .001) and had significantly longer fluoroscopy times (mean, 1.3 min for PG vs 4.8 min for POG; P < .0001). NRS scores, morphine doses, total room times, technical success, complication rates, and QOL did not differ significantly between groups. The one major complication, a misplaced PG in the peritoneal cavity, followed a technical failure of POG creation. CONCLUSIONS: Despite the differences in insertion technique and tube caliber, the measured outcomes of POG and PG are comparable.

Conservative Management of Invasive Placenta Using Combined Prophylactic Internal Iliac Artery Balloon Occlusion and Immediate Postoperative Uterine Artery Embolization.

PURPOSE: The objective of the study was to evaluate the efficacy and safety of combined prophylactic intraoperative internal iliac artery balloon occlusion and postoperative uterine artery embolization in the conservative management (uterine preservation) of women with invasive placenta undergoing scheduled caesarean delivery. METHODS: Ten women (mean age 35 years) with invasive placenta choosing caesarean delivery without hysterectomy had preoperative insertion of internal iliac artery occlusion balloons, intraoperative inflation of the balloons, and immediate postoperative uterine artery embolization with absorbable gelatin sponge. A retrospective review was performed with institutional review board approval. Outcome measures were intraoperative blood loss, transfusion requirement, hysterectomy rate, endovascular complications, surgical complications, and postoperative morbidity. RESULTS: All women had placenta increta or percreta, and concomitant complete placenta previa. Mean gestational age at delivery was 36 weeks. In 6 women the placenta was left undisturbed in the uterus, 2 had partial removal of the placenta, and 2 had piecemeal removal of the whole placenta. Mean estimated blood loss during caesarean delivery was 1.2 L. Only 2 patients (20%) required blood transfusion. There were no intraoperative surgical complications, endovascular complications, maternal deaths, or perinatal deaths. Three women developed postpartum complications necessitating postpartum hysterectomy; the hysterectomy rate was therefore 30% and uterine preservation was successful in 70%. CONCLUSION: Combined bilateral internal iliac artery balloon occlusion and uterine artery embolization may be an effective strategy to control intraoperative blood loss and preserve the uterus in patients with invasive placenta undergoing caesarean delivery.

Efficacy of Ovarian Artery Embolization for Uterine Fibroids: Clinical and Magnetic Resonance Imaging Evaluations.

PURPOSE: The objective of the study was to assess the efficacy of ovarian artery embolization (OAE) treatment for symptomatic uterine leiomyomas. METHODS: A retrospective review of 17 patients who underwent OAE in conjunction with uterine artery embolization in a 6-year period (2006-2012) was performed. Ten patients had previous failed embolization, while 7 had not received any embolization therapy before. Percent uterine volume change, percent dominant fibroid volume change, and percent dominant fibroid infarction were assessed with magnetic resonance (MR) imaging. Resolution of menorrhagia, dysmenorrhea/pain, and bulk and/or pressure symptoms including urinary frequency were evaluated clinically. Change in menopausal state was also an outcome of interest. RESULTS: Mean MR imaging follow-up was performed 3 months post-OAE. MR images showed complete infarction in the majority of cases (64.7%; n = 11), with infarction rates of 90%-100% in 3 cases, 1 case with 30%-50% infarction, and 2 cases with 0%-10% infarction. Average uterine size reduction on MR was 32.3% (95% confidence interval [CI]: 22.5%-42.2%; P < .001). The average size reduction for the dominant fibroid was 42.4% (95% CI: 27.7%-57.0%; P = .01). The mean time to final follow-up visit was 11 months. At this point complete symptom resolution (menorrhagia, dysmenorrhea and bulk-related) was achieved in 82.4% (n = 14) of cases. At the final follow-up 11.8% (n = 2) of cases reported menopause. CONCLUSIONS: We observed OAE to be an effective and safe adjunct to uterine artery embolization when hypertrophic ovarian artery(ies) require intervention. However, incomplete fibroid infarction of 23% remains a concern with a potential for long-term treatment failure. In addition, long-term effect on ovarian function is uncertain.

Radiofrequency coil for the creation of large ablations: ex vivo and in vivo testing.

PURPOSE: Various radiofrequency (RF) ablation electrode designs have been developed to increase ablation volume. Multiple heating cycles and electrode positions are often required, thereby increasing treatment time. The objective of this study was to evaluate the performance of a high-frequency monopolar induction coil designed to produce large thermal lesions (>3 cm) with a single electrode insertion in a treatment time of less than 10 minutes. MATERIALS AND METHODS: A monopolar nitinol interstitial coil operated at 27.12 MHz and 200 W was evaluated. Ex vivo performance was tested in excised bovine liver (n = 22). In vivo testing (n = 10) was conducted in livers of seven Yorkshire pigs. Visual inspection, contrast-enhanced computed tomography (CT), and pathologic evaluation of ablation zones were performed. RESULTS: Average ablation volumes in ex vivo and in vivo tests were 60.5 cm(3) ± 14.1 (5.9 × 4.4 × 4.4 cm) and 57.1cm(3) ± 13.8 (6.1 × 4.5 × 4.1cm), with average treatment times of 9.0 minutes ± 3.0 and 8.4 minutes ± 2.7, respectively. Contrast-enhanced CT ablation volume measurements corresponded with findings of gross inspection. Pathologic analysis showed morphologic and enzymatic changes suggestive of tissue death within the ablation zones. CONCLUSIONS: The RF ablation coil device successfully produced large, uniform ablation volumes in ex vivo and in vivo settings in treatment times of less than 10 minutes. Ex vivo and in vivo lesion sizes were not significantly different (P = .53), suggesting that the heating efficiency of this higher-frequency coil device may help to minimize the heat-sink effect of perfusion.

Radiofrequency ablation of hepatocellular carcinoma as a bridge to liver transplantation.

BACKGROUND: Radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) is widely utilized as a bridge to liver transplant with limited evidence to support efficacy. The purpose of the present study was to measure the effect of RFA on time to drop-off in HCC-listed patients. METHODS: Patients with Milan criteria tumours listed between January 1999 and June 2007 were stratified into RFA (n= 77) and No Treatment groups (n= 93). RESULTS: The primary effectiveness of RFA was 83% (complete radiographic response). RFA was associated with a longer median wait time to transplant (9.5 vs. 5 months). Tumour-specific drop-off events were equivalent between RFA (21%) and No Treatment (12%) groups (P= 0.11). Controlling for wait time, there was no difference in overall (P= 0.56) or tumour-specific drop-off (P= 0.94). Furthermore, there were no differences in 5-year overall or tumour-free survivals from list date or transplant. Using multivariate analysis, the likelihood of receiving a transplant and patient survivals were associated with tumour characteristics (AFP, tumour number and size) and not with bridge therapy or waiting time. DISCUSSION: RFA allows patients to be maintained longer on the waiting list without negative consequences on drop-off or survival compared with no treatment. Post-transplant outcomes are affected more by tumour characteristics than RFA or wait time.

Pathologic assessment of radiofrequency ablation of pulmonary metastases.

PURPOSE: To evaluate pathologically the effectiveness of radiofrequency (RF) ablation in the treatment of pulmonary metastases. MATERIALS AND METHODS: Patients with multiple pulmonary metastases scheduled for surgical resection were prospectively enrolled. Patients underwent RF ablation of one percutaneously accessible tumor and within 2-4 weeks underwent surgical resection of the ablated tumor and any additional lesions. Resected tumors all were assessed by routine light microscopy, and selected tumors were assessed by immunohistochemistry with MIB1 and proliferative cell nuclear antigen (PCNA). Relationship of ablation zone to the tumor and viability of the ablated tumors were assessed. RESULTS: Nine patients (four men and five women) 46-76 years of age were included in the study. Four patients had metastatic colorectal carcinoma, and five patients had metastases from soft tissue sarcomas. Ablated tumors ranged from 1.0-3.0 cm in diameter. Each target lesion was completely encompassed by the ablation zone. All tumor tissue within the ablation zone showed characteristic changes of coagulative necrosis with hematoxylin and eosin staining. Tumors showed preservation of MIB1 staining but loss of PCNA protein staining. RF ablation resulted in complete coagulative necrosis of all the pulmonary metastases treated in the study. CONCLUSIONS: Although this series is small, it provides histologic support for RF ablation as an effective treatment for selected pulmonary metastases.

Psychological distress associated with active surveillance in patients younger than 70 with a small renal mass.

PURPOSE: To compare the psychological distress throughout several predefined disease time points in patients younger than 70 with small renal masses (SRMs) treated with either active surveillance (AS) or ablative/surgical therapy. METHODS: Using the Edmonton Symptom Assessment System - revised (ESAS-r) questionnaire, we focused on psychological distress symptoms in all consecutive patients with an SRM between 2014 and 2017. We further evaluated the psychological distress sub-score (PDSS) of ESAS-r, consisting of the sum scores of anxiety, depression, and well-being. PDSS of patients treated with AS or ablation/surgery were compared at 4 distinct time points (before and after diagnosis, after a biopsy is performed, and at last follow-up). Multivariable linear regression models were performed to assess factors associated with worse PDSS (1-point score increase). RESULTS: We examined 477 patients, of whom 217 and 260 were treated with AS and surgery/ablation, respectively. Similar ESAS-r and PDSS scores were shown at all predefined disease time points except following an SRM biopsy and at last, follow-up, where AS-treated patients with a biopsy-proven malignancy had significantly worse PDSS (11.4 vs. 6.1, P = 0.035), and (13.2 vs. 5.4, P = 0.004), respectively. At last follow-up, multivariable linear models demonstrated that a biopsy-proven malignancy (B = 2.630, 95% CI 0.024-5.236, P = 0.048) and AS strategy (B = 6.499, 95% CI 2.340-10.658, P = 0.002) were associated with worse PDSS in all patients, and in those who underwent a biopsy, respectively. CONCLUSIONS: Offering standardized psychological supportive care may be required for patients younger than 70 years on AS for SRM, especially for those with a biopsy-proven tumor.

Small Renal Mass Surveillance: Histology-specific Growth Rates in a Biopsy-characterized Cohort.

BACKGROUND: Most reports of active surveillance (AS) of small renal masses (SRMs) lack biopsy confirmation, and therefore include benign tumors and different subtypes of renal cell carcinoma (RCC). OBJECTIVE: We compared the growth rates and progression of different histologic subtypes of RCC SRMs (SRMRCC) in the largest cohort of patients with biopsy-characterized SRMs on AS. DESIGN, SETTING, AND PARTICIPANTS: Data from patients in a multicenter Canadian trial and a Princess Margaret cohort were combined to include 136 biopsy-proven SRMRCC lesions managed by AS, with treatment deferred until progression or patient/surgeon decision. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Growth curves were estimated from serial tumor size measures. Tumor progression was defined by sustained size ≥4 cm or volume doubling within 1 yr. RESULTS AND LIMITATIONS: Median follow-up for patients who remained on AS was 5.8 yr (interquartile range 3.4-7.5 yr). Clear cell RCC SRMs (SRMccRCC) grew faster than papillary type 1 SRMs (0.25 and 0.02 cm/yr on average, respectively, p = 0.0003). Overall, 60 SRMRCC lesions progressed: 49 (82%) by rapid growth (volume doubling), seven (12%) increasing to ≥4 cm, and four (6.7%) by both criteria. Six patients developed metastases, and all were of clear cell RCC histology. Limitations include the use of different imaging modalities and a lack of central imaging review. CONCLUSIONS: Tumor growth varies between histologic subtypes of SRMRCC and among SRMccRCC, which likely reflects individual host and tumor biology. Without validated biomarkers that predict this variation, initial follow-up of histologically characterized SRMs can inform personalized treatment for patients on AS. PATIENT SUMMARY: Many small kidney cancers are suitable for surveillance and can be monitored over time for change. We demonstrate that different types of kidney cancers grow at different rates and are at different risks of progression. These results may guide better personalized treatment.

Arterial embolization for primary postpartum hemorrhage.

PURPOSE: To evaluate the efficacy and safety of arterial embolization (AE) for treatment of primary postpartum hemorrhage (PPH), and the factors associated with clinical success. MATERIAL AND METHODS: A retrospective analysis of all patients undergoing AE for primary PPH at three institutions (N = 43) from 1996 through 2007 was conducted. Patients with an antepartum diagnosis of invasive placenta were excluded from the study. Mean patient age was 31 years +/- 5 (range, 21-40 y). Eighteen women (42%) were primiparous. Delivery details, transfusion requirements, hematology and coagulation results, embolization details, and clinical outcomes were collected. Clinical success was defined as cessation of bleeding without the need for repeat embolization, laparotomy, or hysterectomy after embolization; or death. The Fisher exact test was used to analyze nonparametric data. RESULTS: The clinical success rate was 79% (n = 34). Four patients underwent successful repeat embolization. Two of 35 patients who had not undergone hysterectomy before embolization underwent hysterectomy for continued bleeding (without repeat embolization). One underwent hysterectomy 2 weeks after AE for uterine necrosis. One of eight patients who had undergone hysterectomy before AE required a laparotomy for a large retroperitoneal hematoma, and one patient died from cerebral anoxia secondary to hypotension despite repeat embolization. Clinical success was not related to mode of delivery, cause of PPH, transfusion requirements, time from delivery to embolization, or hysterectomy before AE (P > .05). Patients with active extravasation visualized angiographically were more likely to require repeat embolization (five of 13 [38%] vs 0 of 30 without extravasation; P < .01). CONCLUSIONS: AE for primary PPH is safe and effective. Repeat embolization may be necessary in patients with active extravasation on angiography.

Accuracy of renal tumour biopsy for the diagnosis and subtyping of papillary renal cell carcinoma: analysis of paired biopsy and nephrectomy specimens with focus on discordant cases.

AIMS: Renal tumour biopsy (RTB) is increasingly recognised as a useful diagnostic tool in the management of small renal masses, particularly those that are incidentally found. Intratumoural heterogeneity with respect to morphology, grade and molecular features represents a frequently identified limitation to the use of RTB. While previous studies have evaluated pathological correlation between RTB and nephrectomy, no studies to date have focused specifically on the role of RTB for the diagnosis of papillary renal cell carcinoma (PRCC) and its further subclassification into clinically relevant subtypes. METHODS: This single-institution study evaluated 60 cases of PRCC for concordance between RTB and nephrectomy with respect to diagnosis, grading and subtyping (type 1/type 2). RESULTS: We observed 93% concordance (55 of 59 evaluable cases) between RTB and nephrectomy for the diagnosis of PRCC, although seven tumours (12%) were undergraded on RTB. Subtyping of PRCC on RTB was concordant with nephrectomy in 89% of cases reported as type 1 PRCC on RTB (31/35), but only 40% of cases reported as type 2 PRCC on RTB (4/10). Morphological misclassification of PRCC on RTB was most likely to occur in tumours showing a solid growth pattern. Discordant PRCC subtyping most often occurred in tumours with eosinophilia/oncocytic change. CONCLUSION: There was good concordance between RTB and nephrectomy for the primary diagnosis of PRCC. Although further subtyping of PRCC can aid therapeutic stratification, this can be challenging on RTB and tumours with overlapping or ambiguous features are best reported as PRCC not otherwise specified pending development of more robust methods to facilitate definitive subclassification.

Contemporary results of percutaneous biopsy of 100 small renal masses: a single center experience.

PURPOSE: Percutaneous biopsy of small renal tumors has not been historically performed because of concern about complications and accuracy. We reviewed our experience with percutaneous needle biopsy of small renal masses to assess the safety and accuracy of the procedure, the potential predictors of a diagnostic result and the role of biopsy in clinical decision making. MATERIALS AND METHODS: A total of 100 percutaneous needle biopsies of renal masses less than 4 cm were performed between January 2000 and May 2007 with 18 gauge needles and a coaxial technique under ultrasound and/or computerized tomography guidance. A retrospective chart review was performed to document the complication rate and the ability to obtain sufficient tissue for diagnosis. Tumor size, tumor type (solid vs cystic), image guidance, biopsy number and core length were assessed for the ability to predict a diagnostic biopsy. RESULTS: No tumor seeding or significant bleeding was observed. Of the core biopsies 84 (84%) were diagnostic for a malignant (66) or a benign (18) tumor. Larger tumor size and a solid pattern were significant predictors of a diagnostic result. Histological subtyping and grading were possible on core biopsies in 93% and 68% of renal cell carcinomas, respectively. A total of 20 patients underwent surgery after a diagnostic biopsy. The histological concordance of biopsies and surgical specimens was 100%. CONCLUSIONS: Percutaneous needle biopsy of renal masses less than 4 cm is safe and provides adequate tissue for diagnosis in most cases. Larger tumor size and a solid pattern are significant predictors of a successful biopsy. Renal tumor biopsy decreases the rate of unnecessary surgery for benign tumors and can assist the clinician with treatment decision making, especially in elderly and unfit patients.

Retrospective Single-Arm Cohort Study of Patients with Hepatocellular Adenomas Treated with Percutaneous Thermal Ablation.

PURPOSE: To assess the safety and efficacy of percutaneous thermal ablation for the treatment of hepatocellular adenomas. MATERIALS AND METHODS: This is an ethics board-approved, single-arm, retrospective, cohort study of patients with pathologically proven hepatocellular adenomas treated with percutaneous thermal ablation at a tertiary referral center from 1999 to 2016. Demographic, procedural, and outcome data were collected and summarized with appropriate measures of central tendency and dispersion. Complications were graded per the Society of Interventional Radiology reporting guidelines. Determination of primary and secondary technique efficacies was based on post-procedural imaging. RESULTS: Thirty-six patients (4 male, 32 female) with a median age of 35 years had 44 procedures for the treatment of 58 tumors. Twenty-two percent of patients had prior history of adenoma-related hemorrhage. The median tumor size was 2.1 cm (range 0.6-6.0). The majority of treatments were done on an outpatient basis, under moderate sedation, using radiofrequency ablation with ultrasound guidance. The median procedure time was 85 min. There were two immediate post-procedural hemorrhages (4.5% per procedure). During a median follow-up of 1.7 years (95% CI 0.2-8.0), there were no instances of malignant transformation, adenoma-related hemorrhages, or deaths. The primary and secondary technique efficacy rates were 88 and 100%, respectively. CONCLUSION: Thermal ablation for the treatment of hepatocellular adenoma had a primary and secondary efficacy of 88 and 100%, respectively. The major complication rate was 4.5%. The clinical efficacy during a median follow-up of 1.7 year was 100%.