Use of ethylene vinyl alcohol copolymer for tubal sterilization by selective catheterization in rabbits

PURPOSE: To assess the efficacy of ethylene vinyl alcohol copolymer (Uryx) in nonsurgically occluding the fallopian tube and achieving tubal sterilization in the rabbit model. MATERIALS AND METHODS: Ten mature virgin female New England rabbits underwent transvaginal selective bilateral fallopian tube cannulation with use of a coaxial catheter system under general anesthesia. Selective salpingography was performed bilaterally to assess patency of the fallopian tubes. Ethylene vinyl alcohol copolymer was injected unilaterally through a microcatheter to completely fill the middle portion of the tube. Three to seven days after injection, each animal was bred. Conception was determined by ultrasonography (US) 7-19 days after effective breeding. If pregnant, the rabbit was killed. Otherwise, it was permitted to rebreed until pregnancy was achieved. Histologic specimens of the fallopian tubes were prepared and analyzed. RESULTS: Patency of the fallopian tubes was demonstrated bilaterally in all animals by the free spillage of contrast material into the peritoneum. The delivery of ethylene vinyl alcohol copolymer into the fallopian tubes was successful in all animals but one, in which most of the plug almost immediately extruded into the uterus. Pregnancy was detected by US in the untreated fallopian tube in the nine rabbits that were receptive to breeding. No pregnancies were detected in the injected side. Histologic analysis demonstrated variable degrees of occlusion, fibrosis, and inflammation, with the majority of specimens demonstrating mild to moderate inflammation and moderate to marked fibrosis. CONCLUSION: Ethylene vinyl alcohol copolymer can reliably be placed nonsurgically via the transvaginal approach into the fallopian tubes with use of a coaxial catheter system. Ethylene vinyl alcohol copolymer appears to result in less fibrosis than previously investigated agents and demonstrates a 100% early sterilization rate in the rabbit model.     

选择性输卵管造影与再通术对输卵管近端梗阻的疗效分析

目的 探讨选择性输卵管造影与再通术在诊治输卵管近端梗阻方面的安全性和有效性。方法 １０３例输卵管近端梗阻患者,用自制的导管施行选择性输卵管造影,若输卵管近端仍梗阻,则行输卵管再通术。结果人１３５条输卵管中有５１条仅施行选择性输卵管造影即获得再通,剩下８４条输卵管施行输卵管再通术后６４条获再通,有效率达８５．２％,随访３０例,输卵管再通术后有８例宫内妊娠和１例宫外孕,选择性输卵管造影术后有５例宫内妊     

Selective fallopian tube catheterisation in female infertility: clinical results and absorbed radiation dose

Clinical results of fluoroscopic fallopian tube catheterisation and absorbed radiation doses during the procedure were evaluated in 30 infertility patients with unilateral or bilateral tubal obstruction documented on hysterosalpingography. The staged technique consisted of contrast injection through an intraurine catheter with a vacuum cup device, ostial salpingography with the wedged catheter, and selective salpingography with a coaxial microcatheter. Of 45 fallopian tubes examined, 35 (78%) were demonstrated by the procedure, and at least one tube was newly demonstrated in 26 patients (87%). Six of these patients conceived spontaneously in the follow-up perod of 1–11 months. Four pregnancies were intraurine and 2 were ectopic. This technique provided accurate and detailed information in the diagnosis and treatment of tubal obstruction in infertility patients. The absorbed radiation dose to the ovary in the average standardised procedure was estimated to be 0.9 cGy. Further improvement in the X-ray equipment and technique is required to reduce the radiation dose. Correspondence to: T. Ishigaki     

Double Coaxial Microcatheter Technique for Transarterial Aneurysm Sac Embolization of Type II Endoleaks after Endovascular Abdominal Aortic Repair

PurposeTo evaluate the feasibility and efficacy of transarterial sac embolization with a mixture of N-butyl cyanoacrylate and ethiodized oil (Lipiodol; Guerbet Japan, Tokyo, Japan) (NBCA-LPD) for type II endoleaks after endovascular aortic repair (EVAR) using a double coaxial microcatheter technique.Materials and MethodsA retrospective review was performed of 20 consecutive cases of type II endoleaks treated by transarterial embolization using the technique from August 2010 to June 2013. The treatment indication was persistent type II endoleak over 6 months after EVAR associated with aneurysm expansion ≥ 5 mm in maximum diameter. A 1.9-F nontapered microcatheter was advanced to the aneurysmal sac through a 2.7-F microcatheter, which was coaxially introduced through a catheter. The endpoint of the procedure was intrasaccular filling with NBCA-LPD and occlusion of the feeder of the type II endoleak. The technical success rate was defined as success in transarterial intrasaccular approach followed by embolization of the intrasaccular channel and inflow arteries. Clinical success was defined as aneurysmal sac shrinkage or stabilization (freedom from sac expansion > 5 mm in maximum diameter).ResultsTechnical success was achieved in 18 of 20 cases. During a mean follow-up period of 18.5 months, complete sac occlusion was observed in 13 cases (65%). Clinical success was achieved in 16 cases (80%). No serious complications were observed.ConclusionsThe transarterial intrasaccular approach with a double coaxial microcatheter technique can be successfully performed in most cases, and transarterial aneurysm sac embolization using NBCA-LPD has been proven to be feasible.     

Quantification and Reduction of Reflux during Embolotherapy Using an Antireflux Catheter and Tantalum Microspheres: Ex Vivo Analysis

PurposeTo demonstrate in a porcine model that reflux during embolotherapy can be relatively quantified (ie, as embolization efficiency) and that nontarget embolization can be eliminated by using an antireflux microcatheter.Materials and MethodsRenal artery embolization was performed with radiopaque tantalum microspheres (concentration of 1 g/20 mL) in three swine. Second-order right renal arteries (n = 3) underwent embolization with a 3-F antireflux catheter, and second-order left renal arteries (n = 3) underwent embolization with a 4-F end-hole catheter as a control. After embolization, kidneys were explanted and underwent micro–computed tomographic (microCT) imaging. Three-dimensional volumetric and multiplanar imaging of the kidneys was performed to assess vascular distribution. Digital Imaging and Communications in Medicine data were analyzed, with a threshold algorithm used to create binary images. The number of positive values in a region of interest in the target embolized tissue (upper pole or lower pole) and the nontarget adjacent tissue was determined, and embolization efficiency was calculated. Wilcoxon rank-sum statistical analysis was performed to compare nontarget embolization between infusion catheters.ResultsAll renal arteries underwent successful embolization with tantalum microspheres, with 20 mL (1 g) administered in all dose deliveries. MicroCT provided high-resolution visualization of the renal parenchyma at 70-μm resolution. In control renal arteries, a standard 4-F end-hole catheter had an embolization efficiency of 72%±13. In experimental renal arteries, the antireflux microcatheter had an embolization efficiency of 99.9%±1.0 (P< . 05).ConclusionsA significant decrease in nontarget embolization (ie, reduction in reflux) was possible with an antireflux microcatheter compared with a conventional end-hole catheter.     

Preoperative Transarterial Embolization of Advanced Juvenile Nasopharyngeal Angiofibroma Using n-Butyl Cyanoacrylate: Case-Control Comparison with Microspheres

PurposeTo evaluate the efficacy and safety of transarterial embolization (TAE) with n-butyl cyanoacrylate (nBCA) for juvenile nasopharyngeal angiofibroma (JNA).Materials and MethodsA retrospective review was performed on patients with JNA who underwent TAE and endoscopic resection between 2020 and 2022. Patients embolized with nBCA were identified, and those embolized with microspheres were set as the control group. Data on demographics, symptoms, tumor characteristics, blood loss, adverse events, residual disease, and recurrence were collected, and case-control analysis was performed for the 2 groups. Differences in characteristics between the groups were tested using the Fisher exact and Wilcoxon tests. A generalized linear model (GLM) was used to analyze the univariate and multivariate influences on blood loss.ResultsTwenty patients were included in this study: 13 in the microsphere group and 7 in the nBCA group. The median blood loss was 400 mL (interquartile range [IQR], 200–520 mL) in the nBCA group and 1,000 mL (IQR, 500–1,000 mL) in the microsphere group (P = .028). The GLM confirmed lower blood loss in the nBCA group (relative risk, 0.58 [0.41–0.83]; P = .01). A residual tumor was found in 1 patient in each group (7.7% vs 14.3%; P = 1.000). Recurrence was not observed in any patient. None of the patients experienced adverse events during embolization.ConclusionsTAE of advanced JNA with nBCA glue is safe and effective and can significantly reduce intraoperative blood loss compared with microspheres.     

Tubal obstruction after ligation reversal surgery: results of catheter recanalization

PURPOSE: To evaluate the role of transcervical fallopian tube catheterization in restoring tubal patency after ligation reversal surgery. MATERIALS AND METHODS: Twenty-four women with tubal obstruction after ligation reversal surgery underwent selective salpingography and tubal recanalization. RESULTS: Patency was established in 26 (68%) of 38 anastomotic tubes without complication. In the 13 patients who were followed up and who could conceive only via a recanalized anastomotic tube, there were six (46%) pregnancies: two (15%) successful uterine pregnancies, two (15%) early spontaneous abortions, and two (15%) tubal pregnancies. The mean time from procedure to conception was 2 months. CONCLUSION: Patency of fallopian tubes not visualized at hysterosalpingography after ligation reversal surgery can be established 68% of the time with selective salpingography. In some patients, selective salpingography can be therapeutic. If subsequent conception occurs in these patients, it occurs shortly after the catheterization procedure.     

Fallopian tube obstruction: selective salpingography and recanalization. Work in progress

Seven infertile women, in whom interstitial fallopian tube obstruction (IFTO) was suspected at hysterosalpingography and who were recommended for surgical evaluation and treatment, were treated with catheterization techniques. Selective salpingography with ostial injection demonstrated tubal patency in two patients; direct intratubal salpingography demonstrated patency in another patient. Four patients with a true IFTO underwent fallopian tube recanalization: in the first two, a small soft-tipped guide wire was used, and in the other two, a guide wire and 3-F catheter were used. The suggested catheterization techniques have the potential to make evaluation and treatment of IFTO more efficient, safer, and less expensive than presently used methods.     

Polymerization Properties of n-Butyl Cyanoacrylate Mixed with Ethiodized Oil in the Lymphatic System: In Vivo Investigation in a Rabbit Model

PurposeTo evaluate the polymerization properties of a mixture of n-butyl cyanoacrylate (nBCA) and ethiodized oil in the lymphatic system using an animal model.Materials and MethodsNineteen male Japanese White rabbits underwent 28 lymphatic embolization procedures under fluoroscopic guidance using manually injected mixtures of nBCA and ethiodized oil at ratios of 1:2 (nBCA density of 33%), 1:4 (20%), 1:6 (14%), and 1:8 (11%) via the popliteal lymph node. The time required for polymerization and the distance traveled by the mixture were evaluated and compared among the groups using the Kruskal-Wallis test. Histopathologic intergroup comparisons and time-course changes were also evaluated using embolized lymph nodes.ResultsAmong 23 successful procedures, the mean polymerization times were 14 ± 3, 88 ± 93, 331 ± 292, and 932 seconds ± 540 and the mean distances traveled were 13 ± 10, 31 ± 44, 85 ± 89, and 108 mm ± 35 in the 33% (n = 5), 20% (n = 6), 14% (n = 6), and 11% (n = 6) groups, respectively. The 11% group demonstrated a significantly longer polymerization time than the 33%, 20%, and 14% groups and distance traveled than the 33% group. Pathologically, the embolized lymph nodes showed inflammatory changes and massive necrosis regardless of the nBCA density.ConclusionsPolymerization times and distances traveled were increased when nBCA was diluted with increasing quantitites of ethiodized oil in this rabbit model of lymphatic embolization. These relationships should be considered when dilution is prescribed for clinical use.     

A review of selective salpingography and fallopian tube catheterization.

Use of selective salpingography and fallopian tube recanalization has revolutionized the diagnosis and treatment of infertility. Selective salpingography, a diagnostic procedure in which the fallopian tube is directly opacified through a catheter placed in the tubal ostium, has been used since the late 1980s to differentiate spasm from true obstruction and to clarify discrepant findings from other tests. In fallopian tube recanalization, a catheter and guide wire system is used to clear proximal tubal obstructions. The recanalization procedure is simple for interventional radiologists to perform and is successfully completed in most patients (71%-92%). Pregnancy rates after the procedure have been variable, with an average rate of 30%. The combination of selective salpingography with fallopian tube recanalization has improved the overall management of infertility caused by tubal obstruction. The same catheterization technique used in fallopian tube recanalization is currently being explored for use in tubal sterilization.     

Preoperative Embolization of Metastatic Spinal Cord Compression with n-Butyl Cyanoacrylate: Safety and Effectiveness in Limiting Blood Loss

PurposeTo evaluate the safety and effectiveness of preoperative embolization with n-butyl cyanoacrylate (nBCA) performed for metastatic spinal cord compression (MSCC) in limiting blood loss (BL).Materials and MethodsIn this institutional review board–approved retrospective study, clinical records from 2017 to 2022 were reviewed. Twenty consecutive patients (11 men and 9 women; mean age, 65.8 years ± 10.0; range, 45–82 years) underwent 21 preoperative spine tumor embolizations with nBCA. Angiograms were used to calculate the percentage reduction in tumor vascularity, and relevant clinical data (levels studied and embolized, fluoroscopy time [FT], reference dose [RD], and Kerma area product [KAP]) and operative data (BL and operative time [OT]) were analyzed. Adverse events and outcomes were recorded.ResultsA median of 2 levels were embolized per procedure (range, 1–5) but 4.9 were studied (range, 1–10). After embolization, tumor blush was reduced by a median of 87.3% (range, 50%–90%). The mean FT was 41 minutes ± 15.4 (range, 16–67 minutes), the mean RD was 1,977.1 mGy ± 1,794.3 (range, 450.2–6,319 mGy), and the mean KAP was 180.5 Gy·cm² ± 166.2 (range, 30.4–504 Gy·cm²). The adverse event rate was 1 (4.7%) of the 21 embolizations because a weakness of lower extremities related to swelling was observed. Surgery was performed at a mean of 1.4 days ± 1 (range, 1–5 days) after embolization. The mean surgical estimated BL was 432.5 mL ± 328.5 (range, 25–1,100 mL), and the mean OT was 210.1 minutes ± 97.4 (range, 57–489 minutes).ConclusionsPreoperative embolization of tumors resected for MSCC with nBCA is a safe procedure allowing for performance of surgery with acceptable BL.     

The role of diagnostic magnetic resonance hysterosalpingography in the evaluation of fallopian tubal occlusion of female infertility: A meta-analysis

ObjectiveTo evaluate the diagnostic performance of magnetic resonance hysterosalpingography for fallopian tubal occlusion in the context of female infertility when compared to the diagnostic performance of conditional X-ray hysterosalpingography.MethodsPubMed, EMBASE, Web of Science, EBSCO, Cochrane Library database, Scopus were searched for studies in which magnetic resonance hysterosalpingography and X-ray hysterosalpingography were used as diagnostic tools for tubal occlusion assessment; databases were searched through April 2020. Two researchers conducted study inclusion assessment, data extraction, a systematic review, and pooled meta-analysis independently. Stata 15.1 software was used to analyze the pooled sensitivity, specificity, diagnostic odds ratio, positive and negative likelihood ratios, and the area under the summary receiver-operating characteristic curve of magnetic resonance hysterosalpingography.ResultsA total of five studies involving 101 patients and 198 fallopian tubes were finally included. Compared with the conditional X-ray hysterosalpingography (the imaging gold standard), the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and the area under the curve of magnetic resonance hysterosalpingography for tubal occlusion were 0.91 (95% CI: 0.48–0.99), 1.00 (95% CI: 0.87–1.00), 230.47 (95% CI: 6.79–7824.72), 0.09 (95% CI: 0.01–0.80), 2676.10 (95% CI: 61.35–120,000), and 1.00 (95% CI: 0.99–1.00), respectively. Subgroup analyses revealed that viscosity of contrast agent (P = 0.024) and test order (P = 0.036) affected the accuracy of MR-HSG to evaluate tubal occlusion.ConclusionsOur meta-analysis indicated magnetic resonance hysterosalpingography may serve as an alternative for further evaluation of fallopian tubal occlusion of female infertility.     

Selective transcervical fallopian tube catheterization: technique update

A technique of transcervical fallopian tube catheterization involving use of a new vacuum hysterograph and coaxial catheter set is described. In 25 women, selective catheterization of the uterine cornua was accomplished with a 94% success rate. Ostial salpingography permitted visualization of 26% of the 46 tubes found to be obstructed or poorly visualized with conventional hysterosalpingography. Recanalization was successful in 96% of 28 proximal tubal obstructions and in 33% of six midisthmic obstructions unrelated to surgery. Recanalization attempts resulted in tubal perforations without apparent clinical effects in four tubes, one with proximal and three with midisthmic postsurgical obstructions. The new hysterograph with coaxial catheter set is more suitable for recanalization of the obstructed fallopian tubes than is the previously used balloon catheter set.     

Fluoroscopically guided transcervical fallopian tube recanalization of post-sterilization reversal mid-tubal obstructions

Purpose: To assess the technical success and early outcome of fluoroscopically guided transcervical fallopian tube recanalization (FTR) in mid-tubal occlusion following sterilization reversal surgery. Methods: From July 1995 to January 1998, patients with greater than 12 months secondary infertility underwent hysterosalpingography (HSG). FTR was performed in proximal or mid-tubal occlusion. Cases of FTR in mid-tubal occlusion were included in this study. Technical success (defined as complete tubal patency) using a standard guidewire and hydrophilic glidewire, the number of patients with at least one patent tube, and the intrauterine and ectopic pregnancy rates were determined. Results: Twenty-six infertile patients with previous sterilization reversal underwent HSG. Eight of 26 (31%) patients (mean age 32 years, range 23–37 years), had attempted FTR for mid-tubal occlusion at the site of surgical anastomosis. Fourteen tubes were attempted as there were two previous salpingectomies. Technical success was achieved in eight of 14 (57%) tubes attempted, resulting in five of eight (62%) patients having at least one patent tube. At follow-up (mean 18 months, range 12–28 months) in these five patients there was one intrauterine pregnancy. There were no ectopic pregnancies. Conclusions: FTR in mid-tubal obstruction in infertile patients following sterilization reversal surgery is technically feasible and may result in intrauterine pregnancy. In this small group there was a lower technical success rate and lower pregnancy rate than in unselected proximal tubal occlusion.     

应用改良装置治疗输卵管阻塞(附800例分析)

目的 评价用一种改良装置对单侧或双侧输卵管阻塞的再通效果。方法 于1995年11月至2002年10月我院放射科对800例年龄为24～42岁不孕妇女经造影证实为单侧性或双侧性阻塞的1489条输卵管应用美国Cook公司产改良装置实施了介入再通术治疗。该技术操作是在X线监视下经宫腔将导管选送至输卵管开口端而进行选择性输卵管造影与输卵管再通术。结果 确诊有阻塞的1489条输卵管，经再通术治疗后，有1137条输卵管得以复通，复通率为76．4％，导管一次性插管成功率为98．8％。结论 用于输卵管再通术的改良装置兼具多方面优点，诸如操作灵活，疗效显，经济实用，因而值得推广。     

Selective salpingography and fallopian tube recanalization

Obstruction of the uterine (proximal) end of the fallopian tube is noted on up to 20% of hysterosalpingograms and has a variety of underlying causes. Definitive diagnosis and treatment in the past have required laparoscopy or laparotomy with tubal resection. Selective salpingography and fallopian tube recanalization with fluoroscopically guided catheters has emerged as an improved method both for diagnosis and treatment in these patients. Technical success rates for overcoming the obstruction and visualizing distal tubal anatomy range from 76% to 95%. Pregnancy rates after the procedure vary depending on the patient populations studied; however, early results indicate a greater than 50% intrauterine pregnancy rate by 1 year. The rate of ectopic pregnancy is approximately 10% and that of early tubal reocclusion is less than 30%. Selective salpingography and fallopian tube recanalization is recommended as the first intervention in patients with obstruction of the proximal fallopian tube.     

Microcatheter Looping to Facilitate Aneurysm Selection in Coil Embolization of Paraclinoid Aneurysms

ObjectiveDescribed herein is a microcatheter looping technique to facilitate aneurysm selection in paraclinoid aneurysms, which remains to be technically challenging due to the inherent complexity of regional anatomy.ResultsThrough this looping technique, a total of 59 paraclinoid aneurysms were successfully treated. After aneurysm selection as described, single microcatheter technique (n = 25) was most commonly used to facilitate coiling, followed by balloon protection (n = 21), stent protection (n = 7), multiple microcatheters (n = 3), and stent/balloon combination (n = 3). Satisfactory aneurysmal occlusion was achieved through coil embolization in 44 lesions (74.6%). During follow-up of 53 patients (mean interval, 10.9 ± 5.9 months), only one instance (1.9%) of major recanalization was observed. There were no complications related to microcatheter looping.ConclusionThis microcatheter looping method facilitates safe and effective positioning of microcatheter into domes of paraclinoid aneurysms during coil embolization when other traditional microcatheter selection methods otherwise fail.     

Fallopian tube occlusion with use of a small intestine submucosa device: evaluation in a rabbit model

PURPOSE: The present study evaluates the short- and midterm efficacy of a small intestinal submucosa (SIS) device for fallopian tube occlusion in rabbits. MATERIALS AND METHODS: In a pilot study, several SIS device designs were tested for positional stability (absence of migration). The design selected for further testing consisted of a center of spongy SIS surrounded by an SIS sheet and held together by a 0.006-inch wire helix with two barbs. It was delivered on the tip of a short coaxial 3-F/5-F catheter set. Using this design, bilateral transuterine fallopian tube occlusion was performed in eight New Zealand White rabbits. Follow-up consisted of plain radiography at 2 weeks and hysterosalpingography at 6 weeks (n = 4 animals; eight tubes), 12 weeks (n = 2 animals; four tubes), or 24 weeks (n = 2 animals; four tubes). Thereafter, the animals were killed and the fallopian tubes were harvested for histologic evaluation. RESULTS: A single device was placed successfully in each fallopian tube. Fifteen of 16 devices (94%) remained in place throughout follow-up. One device migrated into the vagina at 2-week follow-up. Hysterosalpingography of the 15 tubes with occluders in place showed occlusion in seven of seven (100%) at 6 weeks, three of four (75%) at 12 weeks, and two of four (50%) at 24 weeks. Histologic evaluation revealed luminal occlusion by reorganized SIS containing macrophages, fibrocytes, and scant foreign-body giant cells. Only a mild inflammatory reaction was observed around the tube. In the animals with recanalization at 12 and 24 weeks, new channels were found alongside the original still-occluded fallopian tube lumen. CONCLUSIONS: The original lumen of the fallopian tube was effectively occluded by the SIS occluder, which was remodeled within the fallopian tubes of rabbits. Partial peripheral recanalization was observed over time.     

Evaluation of transcatheter arterial embolization with coaxial microcatheter and micro-coil for vascular lesions]

Transcatheter arterial embolization using a coaxial microcatheter and micro-coil was performed in eight patients with vascular lesions; one each with aneurysm of the basilar artery, cerebellar artery, and pancreatic artery, pseudoaneurysm of the common hepatic artery, gastroduodenal artery, and gluteal artery, carotid-cavernous fistula, and thoracic paraspinal arteriovenous malformation. Complete occlusion was achieved in five patients with aneurysm and pseudoaneurysm by occluding the aneurysmal cavity and/or the orifice. A patient with recurrent carotid-cavernous fistula was also completely embolized. A case of basilar artery aneurysm resulted in partial occlusion because the posterior cerebral artery originated from the aneurysm. The unsatisfactory result in a case of paraspinal AVM was due to its wide extension with multiple feeding arteries. No apparent complication was seen. In conclusion, super-selective arterial embolization therapy with coaxial microcatheter and micro-coils was found to be a useful method for vascular lesions that would have been technically difficult to embolize with the standard catheter and coils.     

Occlusion of the fallopian tube by selective transcatheter radiofrequency electrocoagulation: an experimental study in rabbits

PURPOSE: To test the feasibility of performing transcervical fallopian tube occlusion in a rabbit model with use of unipolar radiofrequency (RF) electrocoagulation. MATERIALS AND METHODS: Under fluoroscopic guidance, transvaginal catheterization of the right or left fallopian tube was first performed with use of a coaxial technique in 20 rabbits. With a metal guide wire protruding from the catheter serving as the active electrode, RF electrocoagulation was performed. The power output was set to 200 W and the current was applied for 20 seconds. The fallopian tube on the contralateral side and the uterus were used as controls. Rabbits were randomly designated to be killed either 2 days (group I, n = 10) or 30 days (group II, n = 10) after the procedure, and tubal patency and histologic changes were evaluated. RESULTS: In group I, significant necrosis of the endosalpinx caused by RF electrocoagulation was found in all 10 rabbits. In group II, the occluded fallopian tube showed fibrosis of the wall in all 10 rabbits, but there was no tissue damage to adjacent organs. Histologic findings in the contralateral fallopian tubes were normal in all 20 rabbits. CONCLUSION: Transcatheter RF electrocoagulation proved to be a safe nonsurgical alternative for occlusion of the fallopian tubes in rabbits.