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.

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.

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 (SRM^RCC) 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 SRM^RCC 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 (SRM^ccRCC) grew faster than papillary type 1 SRMs (0.25 and 0.02 cm/yr on average, respectively, p =  0.0003). Overall, 60 SRM^RCC 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 SRM^RCC and among SRM^ccRCC, 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.

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.

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.

Which G-Tube to Use in Pullers: Assessment of Pull Pressures on Skin Models to Determine Optimal Catheter Choice in Patients with Recurrent Pulled Gastrostomy Tubes

INTRODUCTION

Pulled or dislodged gastrostomy catheters represent a common complication associated with percutaneous gastrostomy and are a common cause of recurrent visits in patients with altered mental status. We intended to perform an experiment to compare the pull forces required to dislodge different commonly used gastrostomy catheters.

MATERIALS AND METHODS

We used a digital force gauge device to measure the pull forces required to dislodge three types of 20 French gastrostomy catheters in double-layer skin models. These included the Flow 20 Pull Method (Cook Medical, Bloomington, IN, USA), Entuit Gastrostomy BR Balloon Retention feeding tube (Cook Medical, Bloomington, IN, USA), and Ponsky Non-Balloon Replacement Gastrostomy Tube (CR Bard Inc, Salt Lake City, Utah, USA). The catheters were inserted into the skin model using the same technique as would be utilized in a patient.

RESULTS

The mean forces measured to dislodge the per-oral Flow 20 Pull Method, Entuit Thrive Balloon Retention, and button-type retention Ponsky replacement catheters were 35.6, 22.8, and 20.6 Newtons, respectively. The pull method per-oral gastrostomy catheter required significantly more pull force to dislodge than both the Ponsky button-type retention catheter and the Entuit balloon retention catheters. There was no significant difference in the pull force required to dislodge the Ponsky replacement catheter and the Entuit balloon retention catheter.

CONCLUSIONS

Per-oral image-guided gastrostomy with pull-method button-type retention catheters may be the ideal choice in patients at high risk of tube dislodgment.

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.

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.

Renal Tumor Biopsy for Small Renal Masses: A Single-center 13-year Experience

BACKGROUND

Renal tumor biopsy (RTB) for the characterization of small renal masses (SRMs) has not been widely adopted despite reported safety and accuracy. Without pretreatment biopsy, patients with benign tumors are frequently overtreated.

OBJECTIVE

To assess the diagnostic rate of RTBs, to determine their concordance with surgical pathology, and to assess their impact on management.

DESIGN, SETTING, AND PARTICIPANTS

This is a single-institution retrospective study of 529 patients with biopsied solid SRMs ≤4 cm in diameter. RTBs were performed to aid in clinical management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Diagnostic and concordance rates were presented using proportions. Factors that contributed to a diagnostic biopsy were identified using a multivariable logistic regression.

RESULTS AND LIMITATIONS

The first biopsy was diagnostic in 90% (n=476) of cases. Of the nondiagnostic biopsies, 24 patients underwent a second biopsy of which 83% were diagnostic. When both were combined, RTBs yielded an overall diagnostic rate of 94%. Following RTB, treatment could have been avoided in at least 26% of cases because the lesion was benign. Tumor size and exophytic location were significantly associated with biopsy outcome. RTB histology and nuclear grade were highly concordant with final pathology (93% and 94%, respectively). Adverse events were low (8.5%) and were all self-limited with the exception of one. Although excellent concordance between RTB and final pathology was observed, only a subset of patients underwent surgery following biopsy. Thus it is possible that some patients were misdiagnosed.

CONCLUSIONS

RTB of SRMs provided a high rate of diagnostic accuracy, and more than a quarter were benign. Routine RTB for SRMs informs treatment decisions and diminishes unnecessary intervention. Our results support its systematic use and suggest that a change in clinical paradigm should be considered.

PATIENT SUMMARY

Renal tumor biopsy (RTB) for pretreatment identification of the pathology of small renal masses (SRMs) is safe and reliable and decreases unnecessary treatment. Routine RTB should be considered in all patients with an indeterminate SRM for which treatment is being considered.

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.

Minimally invasive fetal therapy for hydropic lung masses: three different approaches and review of the literature

OBJECTIVE

To report three different antenatal therapeutic approaches for fetal lung masses associated with hydrops.

METHODS

Three prospectively followed cases are described, and all 30 previously published minimally invasive cases of fetal therapy for hydropic lung masses are reviewed.

RESULTS

Three hydropic fetuses with large intrathoracic lung masses presented at 17, 25 and 21 weeks of gestation, respectively. An aortic feeding vessel was identified in each case and thus a bronchopulmonary sequestration (BPS) was suspected. Under ultrasound guidance, the feeding vessel was successfully occluded with interstitial laser (Case 1), radiofrequency ablation (RFA) (Case 2) and thrombogenic coil embolization (Case 3). Complete (Cases 1 and 2) or partial (Case 3) resolution of the lung mass and hydrops was observed. A healthy infant was born at term after laser therapy (Case 1), and the involved lung lobe was resected on day 2 of postnatal life. In Case 2, hydrops resolved completely following RFA, but an iatrogenic congenital diaphragmatic hernia and abdominal wall defect became apparent 4 weeks later. The neonate died from sepsis following spontaneous preterm labor at 33 weeks. In Case 3, despite technical success in complete vascular occlusion with coils, a stillbirth ensued 2 days after embolization.

CONCLUSIONS

The prognosis of large microcystic or echogenic fetal chest masses associated with hydrops is dismal. This has prompted attempts at treatment by open fetal surgery, with mixed results, high risk of premature labor and consequences for future pregnancies. We have demonstrated the possibility of improved outcome following ultrasound-guided laser ablation of the systemic arterial supply. Despite technical success, RFA and coil embolization led to procedure-related complications and need further evaluation.

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.

Multidisciplinary Canadian consensus recommendations for the management and treatment of hepatocellular carcinoma

Globally, hepatocellular carcinoma (hcc) is the third most common cause of death from cancer, after lung and stomach cancer. The incidence of hcc in Canada is increasing and is expected to continue to increase over the next decade. Given the high mortality rate associated with hcc, steps are required to mitigate the impact of the disease. To address this challenging situation, a panel of 17 hcc experts, representing gastroenterologists, hepatologists, hepatobiliary surgeons, medical oncologists, pathologists, and radiologists from across Canada, convened to provide a framework that, using an evidence-based approach, will assist clinicians in optimizing the management and treatment of hcc. The recommendations, summarized here, were developed based on a rigorous methodology in a pre-specified process that was overseen by the steering committee. Specific topics were identified by the steering committee and delegated to a group of content experts within the expert panel, who then systematically reviewed the literature on that topic and drafted the related content and recommendations. The set of recommendations for each topic were reviewed and assigned a level of evidence and grade according to the levels of evidence set out by the Centre for Evidence-based Medicine, Oxford, United Kingdom. Agreement on the level of evidence for each recommendation was achieved by consensus. Consensus was defined as agreement by a two-thirds majority of the 17 members of the expert panel. Recommendations were subject to iterative review and modification by the expert panel until consensus could be achieved.

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.

Ablative Technologies in the Management of Patients with Primary and Secondary Liver Cancer: An Overview

Interventional ablative technologies have played an increasingly important role in the management of patients with primary or secondary liver malignancies. Ethanol and acetic acid ablation were the primary modalities available 2 decades ago. Today, several new technologies are available, including radiofrequency ablation, cryoablation, and microwave ablation. Radiofrequency ablation is the most widely practiced, however, cryoablation and microwave ablation are reasonable choices in certain situations. Irreversible electroporation is a newer technique, which has yet to enter clinical practice, but shows promising preliminary results. Herein, we provide a brief overview of the above-mentioned technologies with a focus on principles of ablation and technique. We also describe the use of these techniques in the context of cytoreduction, a noncurative approach aimed at reducing the overall tumour burden and providing concomitant survival benefit.

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.

Performance of carotid stenting, vertebroplasty, and EVAR: how many are we doing and why are we not doing more? A survey by the Canadian Interventional Radiology Association

OBJECTIVE

To determine the percentage of interventional radiologists who currently perform 3 interventional procedures: carotid stenting, vertebroplasty, and endovascular aneurysm repair (EVAR) in Canada, and impediments to their future performance by other interventional radiologists.

METHODS

An anonymous online survey was emailed to all members of the Canadian Interventional Radiology Association (CIRA). The survey was open for a period of 2 months.

RESULTS

A total of 75 survey responses were received (of an estimated 247). Carotid stenting, vertebroplasty, and EVAR were performed at 40%, 59%, and 46% of respondents' centres respectively. Wait times, from referral to consultation, and from consultation to procedure, were both typically between 2 to 4 weeks, longer for EVAR. Of respondents currently not performing these procedures, 26%, 28%, and 16% anticipated beginning to perform carotid stenting, vertebroplasty, and EVAR, respectively, in the proceeding year from time of survey. Of respondents who wished to perform the procedure, the greatest impediments were a lack of training, lack of a referral base, and lack of support from their radiology department and (or) colleagues.

CONCLUSIONS

Although carotid stenting, vertebroplasty, and EVAR were being performed at about one-half of respondent's centres, and there will likely be greater adoption of the procedures in the near future, there remain substantial impediments. The greatest impediments to additional radiologists performing these procedures were a lack of training, lack of referral base, and lack of support from their radiology department and (or) colleagues. The former impediment suggested an unmet need for additional training courses.

Computed tomography angiography in abdominal aortic endoleaks: what is the optimal protocol?

OBJECTIVE

To evaluate the roles of noncontrast and delayed phases of computed tomography angiography (CTA) for optimization of the CTA protocol in endoleak detection.

METHODS

CTAs of patients who underwent abdominal aortic endovascular stent-graft placement were retrospectively reviewed. CTA comprised noncontrast, arterial, and delayed phase (2 minutes postcontrast). The arterial phase was compared with a combined arterial and delayed phase and followed by the noncontrast phase to see whether additional information was obtained.

RESULTS

Thirty-eight CTA studies demonstrated endoleak. In 30 studies (79%; 95%CI 64% to 89%), endoleak was detected in the arterial phase. Eight studies (21%; 95%CI 11% to 36%) demonstrated an endoleak only in the delayed phase. No additional information was obtained in the noncontrast phase when compared with a combined reading of the arterial and delayed phases (95%CI 0% to 9%).

CONCLUSION

Delayed-phase imaging is necessary for endoleak detection and obviates a noncontrast phase. Identical parameters should be used for arterial and delayed phases.

Techniques, Safety and Accuracy of Sampling of Renal Tumors by Fine Needle Aspiration and Core Biopsy

PURPOSE

The incidence of renal cell carcinoma is increasing worldwide and there are new treatments for localized as well as metastatic tumors. The traditional role for percutaneous biopsy of renal masses has been limited, and so there is little general experience. There have been concerns about safety and accuracy. This review provides an update on the current techniques, indications and accuracy of needle biopsy of renal tumors.

MATERIALS AND METHODS

PubMed and MEDLINE were searched for English language reports of percutaneous needle core biopsy and fine needle aspiration of renal tumors that were published from 1977 to 2006.

RESULTS

With the development of new biopsy techniques and wider experience with percutaneous probe ablation therapies the risk of tumor seeding appears negligible. Significant bleeding is unusual and almost always self-limiting. At centers with expertise needle core biopsy with or without fine needle aspiration appears to provide adequate specimens for an accurate diagnosis in more than 90% of renal masses.

CONCLUSIONS

Percutaneous biopsy of renal masses appears to be safe and it carries minimal risk of tumor spread. Urologists should consider increasing the indications for renal biopsy of small renal masses that appear to be renal cell carcinoma, especially in elderly and unfit patients. With more experience and followup preoperative biopsy has the potential to decrease unnecessary treatment since up to a third of small renal masses are now reported to be benign at surgery. Percutaneous biopsy may also allow a better selection of renal tumors for active surveillance and minimally invasive ablative therapies. Finally, there is potential for stratifying initial therapy for metastatic renal cell carcinoma by histological subtype and in the future molecular characteristics.

Limitations Influencing Interventional Radiology in Canada: Results of a National Survey by the Canadian Interventional Radiology Association (CIRA)

PURPOSE

To describe the current state and limitations to interventional radiology (IR) in Canada through a large, national survey of Canadian interventional radiologists.

METHODS

An anonymous online survey was offered to members of the Canadian Interventional Radiology Association (CIRA). Only staff radiologists were invited to participate.

RESULTS

Seventy-five (75) responses were received from a total of 247, giving a response rate of 30%. Respondents were split approximately equally between academic centers (47%) and community practice (53%), and the majority of interventional radiologists worked in hospitals with either 200-500 (49%) or 500-1,000 (39%) beds. Procedures listed by respondents as most commonly performed in their practice included PICC line insertion (83%), angiography and stenting (65%), and percutaneous biopsy (37%). Procedures listed as not currently performed but which interventional radiologists believed would benefit their patient population included radiofrequency ablation (36%), carotid stenting (34%), and aortic stenting (21%); the majority of respondents noted that a lack of support from referring services was the main reason for not performing these procedures (56%). Impediments to increasing scope and volume of practice in Canadian IR were most commonly related to room or equipment shortage (35%), radiologist shortage (33%), and a lack of funding or administrative support (28%).

CONCLUSION

Interventional radiology in Canada is limited by a number of factors including funding, manpower, and referral support. A concerted effort should be undertaken by individual interventional radiologists and IR organizations to increase training capacity, funding, remuneration, and public exposure to IR in order to help advance the subspecialty.

Patency of Endovascular Treatment for Central Venous Stenosis: Is There a Difference Between Dialysis Fistulas and Grafts?

PURPOSE

To determine if there is a difference in intervention patency for central venous stenosis (CVS) and occlusion between patients with autogenous hemodialysis fistulas and those with grafts.

MATERIAL AND METHODS

A retrospective study was performed from March 1998 to September 2005 identifying all patients with autogenous fistulas and synthetic grafts who underwent percutaneous angioplasty and/or stent placement for CVS. This study cohort consisted of 38 patients (22 with fistulas and 16 with grafts). Age, sex, type of access, location and side of the access, location and side of the CVS, presence of diabetes, previous hemodialysis catheter placement, date and type of interventions, and outcomes were recorded. The patency of each intervention was estimated by using the Kaplan-Meier survival curves. Univariate and multivariate analysis of the variables were performed.

RESULTS

Eighty-nine interventions were performed; 83 were angioplasties and six were stent placements. Previous catheter placement on the side of the CVS occurred in 29 of the 38 patients (76%). Technical and clinical success of the interventions were 93.3% and 94.4% respectively. The intervention or primary patency rates +/- standard errors at 3, 6, and 9 months in the fistula group were 88.5% +/- 4.8, 59.4% +/- 7.6, and 46% +/- 7.9, respectively. In the graft group, the rates were 78.1% +/- 7.3, 40.7% +/- 9, and 16% +/- 7.3, respectively. With multivariate analysis, intervention patency remained significantly longer for fistulas (P .014) and in patients who did not have a previous catheter (P .001).

CONCLUSION

Longer intervention-free survival for CVS was observed in patients with autogenous fistulas compared with grafts and in patients who did not previously undergo hemodialysis catheter insertion.

Transarterial chemoembolisation for advanced hepatocellular carcinoma: results from a North American cancer centre

AIMS

In Asian countries, transarterial chemoembolisation (TACE) has long been used for palliation of unresectable hepatocellular carcinoma (HCC) without strong evidence of improved survival or quality of life. In 2002, a survival benefi of TACE was shown in two randomised controlled trials in Europe and Hong Kong. The effectiveness of interventions fo HCC is influenced by geographical factors related to diverse patient characteristics and protocols. Therefore, the validation of TACE as palliative modality for unresectable HCC requires confirmation in diverse patient populations. The aim of the present study was to assess the effectiveness of TACE for HCC in a North American population.

MATERIALS AND METHODS

This was a single centre prospective cohort study. Child-Pugh A cirrhosis or better patients wit unresectable HCC and without radiological evidence of metastatic disease or segmental portal vein thrombosis wer assessed between November 2001 and May 2004. Of 54 patients who satisfied the inclusion criteria, 47 underwent 80 TACE sessions. Chemoembolisation was carried out using selective hepatic artery injection of 75 mg/m(2) doxorubicin and lipiodol followed by an injection of embolic particles when necessary. Repeat treatments were carried out at 2-3 month intervals for recurrent disease. The primary outcome was overall survival; secondary outcomes were morbidity and tumour response.

RESULTS

The survival probabilities at 1, 2 and 3 years were 76.6, 55.5 and 50%, respectively. At 6 months after the first intervention, 31% of patients had a partial response and 60% had stable disease by RECIST criteria. Minor adverse events occurred after 39% of TACEs and major adverse events after 20% of sessions, including two treatment-related deaths (4% of patients). One patient had complete cancer remission after undergoing three TACE treatments. Further progression of tumour growth was prevented in 91% of tumours at the 6 month point after the first TACE. At 3 months, serum levels of the tumour marker alpha-feto protein were significantly reduced in patients with elevated levels before TACE.

CONCLUSIONS

The survival probabilities at 1 and 2 years after TACE were comparable with results in randomised studies from Europe and Asia. Most patients tolerated TACE well, but clinicians need to be aware that moderately severe sideeffects require close monitoring and prompt intervention.

Percutaneous Ethanol Injection of Unresectable Medium-to-Large-Sized Hepatomas Using a Multipronged Needle: Efficacy and Safety

Fine needles with an end hole or multiple side holes have traditionally been used for percutaneous ethanol injection (PEI) of hepatomas. This study retrospectively evaluates the safety and efficacy of PEI of unresectable medium-to-large (3.5-9 cm) hepatomas using a multipronged needle and with conscious sedation. Twelve patients, eight men and four women (age 51-77 years; mean: 69) received PEI for hepatomas, mostly subcapsular or exophytic in location with average tumor size of 5.6 cm (range: 3.5-9.0 cm). Patients were consciously sedated and an 18G retractable multipronged needle (Quadrafuse needle; Rex Medical, Philadelphia, PA) was used for injection under real-time ultrasound guidance. By varying the length of the prongs and rotating the needle, the alcohol was widely distributed within the tumor. The progress of ablation was monitored by contrast-enhanced ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) after each weekly injection and within a month after the final (third) injection and 3 months thereafter. An average total of 63 mL (range: 20-154 ml) of alcohol was injected per patient in an average of 2.3 sessions. Contrast-enhanced CT, ultrasound, or MRI was used to determine the degree of necrosis. Complete necrosis was noted in eight patients (67%), near-complete necrosis (90-99%) in two (16.7%), and partial success (50-89%) in two (16.7%). Follow-up in the first 9 months showed local recurrence in two patients and new lesions in another. There was no mortality. One patient developed renal failure, liver failure, and localized perforation of the stomach. He responded to medical treatment and surgery was not required for the perforation. One patient had severe postprocedural abdominal pain and fever, and another had transient hyperbilirubinemia; both recovered with conservative treatment. PEI with a multipronged needle is a new, safe, and efficacious method in treating medium-to-large-sized hepatocellular carcinoma under conscious sedation. Its survival benefits require further investigations.

Survey of gynecologists' and interventional radiologists' opinions of uterine fibroid embolization

PURPOSE

To evaluate the opinions of gynecologists and interventional radiologists regarding uterine fibroid embolization (UFE).

METHODS

We mailed surveys to all gynecologists and interventional radiologists practising in Toronto, Ontario. Study criteria excluded those physicians who did not assess or treat patients with uterine fibroids. We evaluated whether they educated patients regarding UFE, together with their opinion of current and future effectiveness of UFE, self-rated knowledge of fibroid treatment options, and recommendations for treatment in several clinical scenarios.

RESULTS

A total of 102 gynecologists (46.4% response rate) and 28 interventional radiologists (51.9% response rate) completed the survey. After applying the exclusion criteria, the final study population was 82 gynecologists and 17 interventional radiologists. Both groups reported high rates of patient education regarding UFE (gynecologists 100% and interventional radiologist 88.2%, P > 0.05). Interventional radiologists had higher self-rated knowledge of UFE (P = 0.05), and gynecologists had higher self-rated knowledge of all other treatment options (P = 0.00). Interventional radiologists had a more favourable opinion of the current effectiveness (P < 0.05) and future use (P > 0.05) of UFE. In 5 of the 7 clinical scenarios, interventional radiologists chose UFE, whereas gynecologists chose other treatment options (P < 0.05).

CONCLUSIONS

Although most gynecologists and intterventional radiologists educate their patients regarding UFE as a treatment option for uterine fibroids, interventional radiologists have greater self-rated knowledge and a higher opinion of current effectiveness and future use and recommend UFE more often for uterine fibroid scenarios.

Percutaneous management of chronic mesenteric ischemia: outcomes after intervention

PURPOSE

To assess the efficacy and durability of percutaneous transluminal angioplasty (PTA)/stent placement for treatment of chronic mesenteric ischemia (CMI).

MATERIALS AND METHODS

A retrospective review of patients treated from January 1986 to August 2003 was conducted. Twenty-nine patients (mean age, 62 years) were treated for clinical symptoms consistent with CMI. Clinical diagnosis was verified with angiographic assessment and PTA with or without stent placement was performed based on angiographic and/or pressure gradient findings. Outcomes were estimated with the Kaplan-Meier method.

RESULTS

A total of 63 interventions were performed in 29 patients during the study period. Of these 63 interventions, 46 PTA and 17 stent implantation procedures were performed. Thirty-four interventions were performed for SMA stenosis/occlusion, 17 interventions for celiac artery stenosis/occlusion, and four interventions were performed on aorto-mesenteric graft stenoses. Technical success was 97%, and clinical success (defined as clinical resolution of symptoms) was 90% (26 of 29 patients). Mean duration of follow-up was 28.3 months. Primary patency for all interventions at 3, 6, and 12 months was 82.7% (95% CI: 68.7-96.7), 78.9% (66.7-91.1), and 70.1% (55.1-85.6), respectively. Primary assisted patency for all interventions at 3, 6, and 12 months was 87.9% (79.0-95.3), 87.9% (79.2-95.1), and 87.9% (77.3-98.3), respectively. An average of 1.9 interventions per patient was required. One major complication occurred (3.4%). There were three minor complications (10.3%).

CONCLUSIONS

Percutaneous intervention for CMI is safe with durable early and midterm clinical success. However, repeated intervention is often required for improved primary assisted patency.

Laparoscopic Ultrasound-Guided Radiofrequency Ablation of Uterine Fibroids

Four patients with symptomatic uterine fibroids measuring less than 6 cm underwent laparoscopic ultrasound-guided radiofrequency ablation (RFA) using multiprobe-array electrodes. Follow-up of the treated fibroids was performed with gadolinium-enhanced magnetic resonance imaging (MRI) and patients' symptoms were assessed by telephone interviews. The procedure was initially technically successful in 3 of the 4 patients and MRI studies at 1 month demonstrated complete fibroid ablation. Symptom improvement, including a decrease in menstrual bleeding and pain, was achieved in 2 patients at 3 months. At 7 months, 1 of these 2 patients experienced symptom worsening which correlated with recurrent fibroid on MRI. The third, initially technically successfully treated patient did not experience any symptom relief after the procedure and was ultimately diagnosed with adenomyosis. Our preliminary results suggest that RFA is a technically feasible treatment for symptomatic uterine fibroids in appropriately selected patients.

Pain after Percutaneous Liver Biopsy for Diffuse Hepatic Disease: A Randomized Trial Comparing Subcostal and Intercostal Approaches

PURPOSE

To compare pain levels as measured by visual analog scale (VAS) and analgesic requirement between intercostal and anterior subcostal ultrasound (US)-guided biopsy.

MATERIALS AND METHODS

Seventy consecutive patients were randomized to undergo biopsy via an intercostal (n = 33) or subcostal (n = 37) approach. The groups were matched with regard to baseline characteristics: mean age, 44 years; age range, 20-70 years; sex, 43 male and 27 female; and indications of hepatitis C in 69%, hepatitis B in 16%, and others in 15%. The VAS score was obtained immediately after biopsy and hourly for 4 hours until the patients were discharged. Analgesic requirements and postprocedural complications were documented.

RESULTS

No significant difference in VAS scores was seen between the groups. At hours 0, 1, 2, 3, and 4, the VAS scores (on a scale of 100) in the intercostal and subcostal groups were 10.3 +/- 16.7 versus 11.8 +/- 16.0 (P = .70), 19.1 +/- 24.0 versus 13.9 +/- 16.2 (P = .30), 11.5 +/- 14.8 versus 11.8 +/- 15.1 (P = .93), 6.2 +/- 8.9 versus 7.5 +/- 11.5 (P = .63), and 5.4 +/- 8.2 versus 4.7 +/- 8.5 (P = .72), respectively. The average VAS was less than 10. In the intercostal biopsy group, 36.4% of patients required additional analgesia after biopsy, compared with 27.0% in the subcostal biopsy group (P = .64). One patient in the intercostal group refused to have future follow-up biopsy even if it was clinically indicated, compared with no such patients in the subcostal biopsy group. No differences in diagnostic samples or major complications were seen in either group.

CONCLUSION

US-guided percutaneous liver biopsy performed with fentanyl and midazolam premedication is a well-tolerated procedure with minimal patient discomfort. The location of the biopsy does not influence the outcome of the procedure.

Needle Tract Seeding after Radiofrequency Ablation of Hepatic Tumors

PURPOSE

To determine the incidence and risk factors associated with needle tract seeding after radiofrequency ablation (RFA) of liver tumors.

MATERIALS AND METHODS

A prospective data base of patients with hepatic tumors treated by RFA from December 1999 until August 2003 was reviewed to identify patients with needle tract seeding. During this period, 200 patients (148 men, 52 women) with 299 lesions underwent 298 treatment sessions. Patients with both primary (153 hepatocellular carcinoma, two cholangiocarcinoma) and a variety of secondary tumors (35 colorectal, 10 other) were treated. RFA was performed percutaneously with computed tomography (CT) and/or ultrasound (US) guidance, or with US guidance at laparoscopy or laparotomy. All procedures were performed with a LeVeen needle electrode. The needle tract was not routinely coagulated or embolized.

RESULTS

Eight patients out of 200 (4%) were identified with needle tract seeding, based on imaging findings or surgical reintervention. This corresponds to a rate of eight of 298 (2.7%) per treatment session and eight of 299 (2.7%) per lesion. Statistically significant risk factors for neoplastic seeding included treatment of a subcapsular lesion (OR = 11.57, P = .007), multiple treatment sessions (OR = 2.0, P = .037), and multiple electrode placements (OR = 1.4, P = .006).

CONCLUSIONS

Neoplastic seeding may occur after RFA of liver tumors. The results show that the frequency of this complication is not insignificant, and are at the upper end of rates reported in the literature of 0.5% to 2.8%. Specific risk factors identified in this study include treatment of subcapsular lesions, patients treated in multiple sessions, and lesions requiring more than one electrode placement.

Risk of Intrauterine Infectious Complications after Uterine Artery Embolization

PURPOSE

To identify risk factors for the development of intrauterine infection following uterine artery embolization.

MATERIALS AND METHODS

A retrospective review of uterine artery embolizations (UAE) performed for the treatment of symptomatic fibroids from January 2000 to July 2003 was conducted. With logistic regression and the Fisher exact test, multiple variables were analyzed as predictors for intrauterine infectious complications requiring medical and/or surgical therapy, including the use of preprocedural antibiotics, embolic agent used, quantity of embolic material, location of fibroids (submucosal, nonsubmucosal), and size and location of the dominant fibroid.

RESULTS

A total of 414 UAE procedures were performed in 410 patients with a technical success rate of 99%. Average age of the patient cohort was 42.8 years (SD, 5.8 years). One hundred forty-eight patients (36.1%) had submucosal fibroids or fibroids projecting submucosally, 262 patients (63.9%) had nonsubmucosal fibroids. Intrauterine infectious complications requiring intravenous antibiotic therapy and/or surgery occurred in five patients (1.2%). A total of five infectious complications requiring therapy occurred in the submucosal group (3.4%) and none in the nonsubmucosal group. Patients within the submucosal group were more likely to develop intrauterine infectious complications than patients with nonsubmucosal fibroids based on univariate analysis (P = .006) but with logistic regression, the association was not significant (P = .079). No significant difference with embolic agent, quantity of embolic particles, use of preprocedure antibiotics, or size of or location of the dominant fibroid was found.

CONCLUSION

No specific risk factor for intrauterine infection following UAE was identified in this study. Infection after UAE is rare and appears to be a sporadic occurrence. Nevertheless, close surveillance is warranted in all women following UAE given the potential morbidity of this complication.

Assessing damage in individual joints in rheumatoid arthritis: a new method based on the Larsen system

OBJECTIVES

To evaluate observer agreement using the Larsen system (LS) and a Modified Larsen system (ML) when assessing individual joints of the hands and wrists in rheumatoid arthritis, and to compare the two systems. To determine the minimally important difference (MID) for the ML.

METHODS

Thirty radiographs of hands and wrists from 10 patients who presented with RA were graded by two blinded observers, using the LS and then the ML. Patients were followed for a mean of 7.2 years (range: 4-10 years). Inter- and intra-observer agreement were calculated using the kappa statistic with linear incremental weights. Inter-observer agreement was also computed for the summed score, using an intraclass correlation coefficient. Inter-observer error was estimated by calculating the mean and standard deviation of the grading differences between the two observers. Prevalence of damage was calculated as a ratio of damage: no damage and expressed as a percentage. Pairs of radiographs were comparatively graded using a seven-point Likert scale.

RESULTS

The kappa statistic for inter-observer agreement was 0.38 (marginal reproducibility) for the LS and 0.52 (good reproducibility) for the ML (P = 0.004). Using a difference of one grade as perfect agreement, it was 0.56 (good reproducibility) for the LS and 0.87 (excellent reproducibility) for the ML (P = 0.001). Intra-observer agreement was high in both systems. The distribution of ML-grade differences varied according to the level of the Likert scale: for "a little bit worse", representing the smallest amount of detectable damage progression, the distribution differences peaked around two grades. This value represented a MID 87% of the time.

CONCLUSIONS

The LS lacks precision for individual joints. The ML, it is proposed, has more detailed definitions of grades, and is more reliable. When pairs of radiographs were compared, a two-grade difference on the ML was the MID.

Elective Non-Removal of the Placenta and Prophylactic Uterine Artery Embolization Postpartum as a Diagnostic Imaging Approach for the Management of Placenta Percreta: A Case Report

BACKGROUND

Placenta percreta, invasion of placental tissue through the uterine wall, is a rare but potentially fatal complication of pregnancy. Historically, the diagnosis was made at laparotomy, usually during Caesarean hysterectomy.

CASE

We describe a case of placenta percreta, in which the placenta was allowed to remain fixed to the uterine wall. Antenatal ultrasound and magnetic resonance imaging techniques were used to establish the diagnosis and guide clinical management. Elective postoperative uterine artery embolization down balloon catheters was used to prevent postpartum hemorrhage and to promote involution and shedding of the placenta. After 6 months, the uterus had involuted to the nonpregnant state.

CONCLUSION

New diagnostic imaging techniques may be used to guide conservative management of placenta percreta, thereby maintaining fertility and avoiding hemorrhage, blood transfusion, and hysterectomy.

Procedural success and patency after percutaneous treatment of thrombosed autogenous arteriovenous dialysis fistulas

PURPOSE

To retrospectively evaluate success and midterm patency after percutaneous thrombectomy, lytic therapy, and angioplasty for thrombosed autogenous arteriovenous dialysis fistulas.

MATERIALS AND METHODS

From March 1996 to September 2001, 24 patients with 25 fistulas presented with 30 episodes of thrombosis of their autogenous fistulas, including 19 forearm radiocephalic fistulas in 18 patients and six upper arm brachiocephalic fistulas in six patients. Patients presented for percutaneous therapy within 48 hours of fistula thrombosis, with the exception of one patient who presented 7 days after thrombosis. Lytic therapy with urokinase or recombinant tissue plasminogen activator (rt-PA) was administered as a bolus into the fistula in 24 cases, with the exception of one case in which a 16-hour infusion of rt-PA was initiated. A mechanical thrombectomy device was used in a single case. Balloon thrombectomy was performed for residual clot. Angioplasty was performed at the arterial inflow, fistula, and outflow veins as required for identified areas of stenosis and/or maceration of thrombus.

RESULTS

Clinical success was achieved in 73% of cases (22 of 30). All patients were followed for a maximum of 66 months (mean, 12 mo). Primary patency rates were 36% at 3 months (95% CI, 18%-54%), 28% at 6 months (95% CI, 12%-46%), and 24% at 1 year (95% CI, 10%-42%). The assisted primary patency rate was 40% (95% CI, 21%-58%) at 3 months and stabilized at 32% at 6 months (95% CI, 15%-50%). The secondary patency rate stabilized at 3 months at 44% (95% CI, 24%-62%) for 15 months. Patency rates after clot removal were not significantly different between upper and lower arm fistulas (P =.14). Total observation time of the cohort of 25 fistulas was 296 months. The complication rate was 7% (two of 30), with one major complication and one minor complication.

CONCLUSION

Salvage of function after percutaneous clot removal from autogenous fistulas involves a steep learning curve initially and is possible with 3-month patency rates that approximate Kidney Disease Outcomes Quality Initiative recommendations for clot removal from polytetrafluoroethylene grafts.

The uncertainty of radio frequency treatment of renal cell carcinoma: findings at immediate and delayed nephrectomy

PURPOSE

Radio frequency thermal therapy for the ablation of renal cell carcinoma has been reported. Outcomes are usually measured by imaging alone. We have performed ex vivo and in vivo experiments using radio frequency in porcine models in our laboratory. We now report our early experience in the treatment of renal cell carcinoma in patients who underwent post-radio frequency radical or partial nephrectomy.

MATERIALS AND METHODS

We treated 10 patients diagnosed with small renal masses with radio frequency. All masses were biopsied before treatment. In 4 patients 5 renal cell carcinomas were treated with radio frequency after surgical exposure of the tumor followed immediately by partial or radical nephrectomy (acute group). Six other patients were treated percutaneously with ultrasound or computerized tomography guided radio frequency under local anesthesia and intravenous sedation 7 days before partial or radical nephrectomy (delayed group). A median of 2 radio frequency cycles was applied. Mean total heating time was 17 minutes 15 seconds. Specimens were analyzed grossly and histologically. Triphasic contrast-enhanced computerized tomography and/or magnetic resonance imaging was performed before and 7 days after radio frequency treatment in the delayed group.

RESULTS

Mean radiological largest diameter of all 11 masses was 2.4 cm. and mean gross diameter was 2.2 cm. Pathological examination demonstrated residual viable tumor in approximately 5% of the volume in 4 of the 5 tumors in the acute group and in 3 of the 6 masses of the delayed group. In 1 delayed case the viable tumor appeared to be in contact with the renal vein. No significant complications were observed in 9 of the 10 patients. In 1 delayed case, a subcapsular hepatic hematoma, biliary fistula and pneumonia developed and resolved.

CONCLUSIONS

Based on our experience, we continue to consider percutaneous radio frequency for the treatment of small renal cell carcinomas as a potentially curative therapy. However, complete tumor cell death appears to be difficult to achieve with our current treatment protocol. More phase II testing is indicated to ensure that this technique is an effective and reproducible treatment alternative.