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.