Management of acute lower gastrointestinal bleeding by pharmaco-induced vasospasm embolization therapy.

BACKGROUND: To report the clinical outcomes of vasospasm embolization technique in treating lower gastrointestinal bleeding (LGIB). METHODS: Fifty LGIB patients (32 men and 18 women; mean age, 70.4 years) with positive contrast extravasation on multidetector computed tomography were treated with pharmaco-induced vasospasm embolization by semiselective catheterization technique. Distal rectal bleeding was excluded. The bleedings in three patients were considered to be tumor related. Eighteen underwent regular hemodialysis, and 22 showed unstable hemodynamic at intervention. RESULTS: Forty-two bleeders were found in superior mesenteric territory and eight in the inferior mesenteric territory. Successful, immediate hemostasis was achieved in 49 (98%) patients. Early recurrent bleeding (<30 days) was found in 13 (26.5%) patients with 6 local rebleeding (12.2%), 5 new-foci bleeding (10.2%), and 2 uncertain foci bleeding (4.1%). Repeated vasospasm embolization therapy was given to five patients, with successful hemostasis in four. All the three tumor-related bleeding patients undergoing vasospasm embolization had ceased bleeding and discharged. Patient-based primary and overall clinical successes were achieved in 73.5% and 83.7%, and lesion-based primary and overall clinical successes were 83.0% and 86.7%, respectively. The 30-day mortality rate was 21.3%, and the 1- and 2-year survival rates were 51.5% and 43.8%. No major procedure-related complications (eg, bowel ischemia) were encountered. CONCLUSION: This study confirmed our prior preliminary conclusion that pharmaco-induced vasospasm embolization is easy, safe, and effective for LGIB. This treatment may be considered the first-line alternative approach for LGIB, especially for patients of advanced age with complex medical problems and/or when vasa rectal embolization isn't feasible.

The Complication of Hepatic Artery Injuries of 1,304 Percutaneous Transhepatic Biliary Drainage in a Single Institute.

PURPOSE: To determine frequency of and assess risk factors for hepatic artery (HA) injury during percutaneous transhepatic biliary drainage (PTBD) and to discuss the technique and report the clinical outcome of embolization for HA injury. MATERIALS AND METHODS: Over a 14-year period (2002-2016), 1,304 PTBD procedures in 920 patients were recorded. The incidence of HA injury was determined, and possible associated risk factors were analyzed. When injury occurred, HA embolization was performed at the site as close to the bleeding point as possible. Clinical outcomes of these patients after embolization were reported. RESULTS: Of 1,304 PTBD procedures, a left-sided approach was used in 722 procedures (55.4%), and intrahepatic duct (IHD) puncture under ultrasound guidance was used in 1,161 procedures (90.1%). The IHD was nondilated in 124 (9.5%) patients. The punctured ductal entry site was peripheral in 1,181 (90.6%) patients. In this series, 8 procedures (0.61%) were complicated by HA injury. IHD dilatation status was the only risk factor (P = .017) for HA injury. Embolization was performed with technical and clinical success in all 8 patients. No recurrent hemobilia, intraabdominal bleeding, or other sequelae of HA injury after embolization was noted during 1 week to 84 months of follow-up. CONCLUSIONS: HA injury is a relatively rare complication of PTBD. IHD dilatation status was the only risk factor for HA injury in this study. When HA injury occurred, embolization therapy was effective in managing this complication.

Pharmaco-induced vasospasm therapy for acute lower gastrointestinal bleeding: a preliminary report.

PURPOSE: To report a novel technique and preliminary clinical outcomes in managing lower gastrointestinal bleeding (LGIB). MATERIALS AND METHODS: Eighteen LGIB patients (11 men and 7 women, mean age: 66.2 years) were treated with artificially induced vasospasm therapy by semi-selective catheterization technique. Epinephrine bolus injection was used to initiate the vascular spasm, and followed by a small dose vasopressin infusion (3-5 units/h) for 3h. The technical success, clinical success, recurrent bleeding and major complications of this study were evaluated and reported. RESULTS: Sixteen bleeders were in the superior mesenteric artery and 2 in the inferior mesenteric artery. All patients achieved successful immediate hemostasis. Early recurrent bleeding (<30 days) was found in 4 patients with local and new-foci re-bleeding in 2 (11.1%) each. Repeated vasospasm therapy was given to 3 patients, with clinical success in 2. Technical success for the 21 bleeding episodes was 100%. Lesion-based and patient-based primary and overall clinical successes were achieved in 89.4% (17/19) and 77.7% (14/18), and 94.7% (18/19) and 88.8% (16/18), respectively. None of our patients had complications of bowel ischemia or other major procedure-related complications. The one year survival of our patients was 72.2 ± 10.6%. CONCLUSIONS: Pharmaco-induced vasospasm therapy seems to be a safe and effective method to treat LGIB from our small patient-cohort study. Further evaluation with large series study is warranted. Considering the advanced age and complex medical problems of these patients, this treatment may be considered as an alternative approach for interventional radiologists in management of LGIB.

Endovascular salvage of immature autogenous hemodialysis fistulas.

PURPOSE: To report the technical success and long-term clinical outcomes of immature arteriovenous fistula (AVF) after percutaneous angioplasty (PTA). MATERIALS AND METHODS: Patients with 58 immature AVF underwent PTA treatment in our institute during the past 9 years. Based on pretreatment ultrasound findings, the immature AVFs were categorized as stenosed, thrombosed, and obliterated type. An optimal entry site was punctured under ultrasound guidance followed by conventional fluoroscopy-guided PTA technique. Technical and clinical success as well as complications were recorded. Patency after angioplasty was estimated using Kaplan-Meier analysis. Predictors of patency were estimated using log-rank test. RESULTS: In our series, 50 % (29 of 58), 20.7 % (12 of 58), and 29.3 % (17 of 58) of immature AVF were stenosed, thrombosed, and obliterated, respectively. Technical and clinical success was achieved in 96.6 % (56 of 58) of cases with 100 % success in both the stenosed and thrombosed lesions and 88.2 % (15 of 17) success in the obliterated lesions. Vascular ruptures occurred in 12.1 % (7 of 58) of lesions. The overall primary and secondary patency rates of the 58 lesions were 45.4 and 84.2 % at 12 months and 36.5 and 80.1 % at 36 months. There were no significant differences of patency between the three types of lesions (p = 0.075 and 0.093) and the two groups of patients with or without residual side branches after intervention (p = 0.527 and 0.644). There was a significant difference of primary patency in patients with vascular rupture (p = 0.012) with a hazard ratio of 3.236. CONCLUSION: PTA could effectively prolong the lifetime of immature AVFs with high technical success. Vessel rupture was predictive of shorter primary patency, and long-term secondary patency was acceptable.

Iodine based radiopacity of experimental blood clots for testing of mechanical thrombectomy devices.

BACKGROUND: Barium sulfate powder used for radiopacity of experimental blood clots (EBCs) for testing mechanical thrombectomy devices (MTD) has negative effects on EBCs mechanical properties. In vitro and in vivo exploration was performed to determine if the iodine based contrast medium will have less negative effects on the EBCs than barium. MATERIALS AND METHODS: Fresh blood from 2 swine was used to create fibrinogen enhanced and thrombin initiated EBC in tubes. Iodine radiopacity was achieved by mixing the blood with 65% Iohexol or by soaking the EBCs for 2 or 24 hours in Iohexol. The EBCs opacified with barium served as controls. In vitro study: The EBCs were subjected to four tests, manual elongation, catheter injection, radiopacity and contrast wash out tests. In vivo study: The common carotid arteries of 2 swine were embolized by either barium EBC or EBC soaked for 24 hours in Iohexol. The duration of radiopacity of the different EBCs was compared. RESULTS: The EBCs opacified with Iohexol initially had higher radiopacity than the barium opacified EBCs. However, their opacity rapidly decreased with saline soaking and, particularly, after they were embolized in live animals. The mechanical properties of Iohexol opacified EBCs were inferior to barium opacified EBCs. The Iohexol mixed EBCs were less firm and elastic and half of them fragmented during catheter injection. The Iohexol soaked EBCs exhibited decreased tensile strength and elasticity compared to the barium EBCs. CONCLUSIONS: Compared to barium, iodine based contrast medium does not offer any advantage for opacifying EBCs.

The efficacy and long-term outcome of microcoil embolotherapy for acute lower gastrointestinal bleeding.

OBJECTIVE: To evaluate the clinical efficacy as well as long-term clinical outcomes of superselective microcoil embolization for lower gastrointestinal bleeding (LGIB). MATERIALS AND METHODS: Between 1997 and 2009, 26 patients with intended transcatheter embolotherapy for LGIB were retrospectively reviewed. Embolization was performed only when the catheter could be advanced to or distal to the mesenteric border of the bowel. The main purpose of our study was to assess technical success, recurrent bleeding rate and complications. We also evaluated the long-term clinical outcome, including late recurrent LGIB, bowel ischemia and the survival rate. RESULTS: Twenty-two bleeding sources were in the territory of superior mesenteric artery and four in the inferior mesenteric artery. Technical success was achieved in 22 patients (84.6%). The target vessel of embolization was vasa recta in seventeen patients and marginal artery in the remaining five patients. Early rebleeding occurred in two patients (7.7%) and bowel ischemia in two patients, of whom the embolized points were both at the marginal artery. Delayed recurrent bleeding (> 30 days) occurred in two angiodysplasia patients. Five patients (19.2%) died within the first 30 days of intervention. Long-term follow-up depicted estimated survival rates of 58.2 and 43.1% after one, and five years, respectively. CONCLUSION: Transcatheter embolotherapy to treat LGIB is effective with low rebleeding and ischemic complications. Considering the advanced age and complex medical problems of these patients, the minimal invasive embolotherapy may be used as both a primary and potentially definitive treatment of LGIB.

Creation of fibrinogen-enhanced experimental blood clots to evaluate mechanical thrombectomy devices for treatment of acute stroke: an in vitro study.

PURPOSE: To explore if addition of fibrinogen to the most commonly used experimental blood clot (EBC) model would improve its mechanical properties and histologic structure. MATERIALS AND METHODS: Fresh blood from three swine was used to create four EBC types. The Gralla model of thrombin-induced barium-opaque EBC served as the control. In three other EBC types, 50 mg, 100 mg, and 200 mg of bovine fibrinogen were added. Evaluation of EBCs was done with three tests: manual elongation, injection through an 8-F catheter, and an opacity test. Thirty EBCs of each type were evaluated with each test. Histologic evaluation followed. RESULTS: The control EBCs had low tensile strength and broke at 165% elongation. However, they were elastic and returned to their original length after catheter injection. The EBCs with fibrinogen exhibited increased tensile strength with increasing fibrinogen doses and withstood elongation to 213% (P < .01). Their elasticity decreased with increased tensile strength, and they remained elongated after catheter injection (P < .01 for EBC with 100 mg and 200 mg fibrinogen). Histologic examination showed more thorough mixing of blood with barium and a significantly increased amount of fibrin after addition of fibrinogen. CONCLUSIONS: Addition of fibrinogen to a Gralla EBC model changes its mechanical properties proportionately to the fibrinogen dose. Fibrinogen increases EBC tensile strength but decreases its elasticity. Fibrinogen also significantly increases the binding of blood cells with fibrin on histologic slides.

Percutaneous retrieval of dislodged central venous port catheter: experience of 25 patients in a single institute.

BACKGROUND: For a dislodged port catheter, percutaneous retrieval by using a loop snare or a basket is the standard technique, with high success. However, once a loop snare fails, the likelihood of success with other tools is considered low. PURPOSE: To report our experience of percutaneous retrieval of dislodged port catheters and to emphasize the usefulness of grasping forceps. MATERIAL AND METHODS: During a 6-year period, a total of 25 dislodged port catheters were retrieved in our institute. The interval between port catheter implantation and dislodged catheter retrieval was 3-85 months (mean 23 months). The time of delayed retrieval ranged from 3 to 604 days (mean 58 days). A loop snare or grasping forceps were used via either the femoral or jugular route. RESULTS: The prevalence of port catheter dislodgement was 0.4% in our institute. All dislodged port catheters were successfully removed, including four patients with delayed retrieval of more than 90 days. A loop snare was used in 20 patients, with technical success in 18. Grasping forceps were used in seven patients, all with success (including the two patients who failed by initial use of a loop snare). No procedure-related complications were encountered, except transient arrhythmia in four patients requiring no medication. CONCLUSION: Although the prevalence of port catheter dislodgement is low, percutaneous attempts at retrieval should be performed in all patients, even in chronic settings. A loop snare is the instrument of choice for retrieval. Grasping forceps can be used as an auxiliary instrument, especially in patients where a loop snare fails.

Imaging of female urethral diverticulum: an update.

Female urethral diverticulum is an uncommon pathologic entity and can manifest with a variety of symptoms involving the lower urinary tract. Selection of the appropriate imaging modality is critical in establishing the diagnosis. Urethrography has traditionally been used in the evaluation of urethral diverticulum but provides only intraluminal information. Ultrasonography is advantageous in that it does not involve ionizing radiation and has the capacity to help detect a diverticulum without contrast agent filling. Multidetector computed tomographic (CT) voiding urethrography yields urethral images during micturition. In addition, the diverticulum and diverticular orifice can be visualized on two- and three-dimensional reformatted CT images. Interactive virtual urethroscopy provides simulated visualization of the intraluminal anatomy and the diverticular orifice. New magnetic resonance imaging techniques that make use of a surface or endoluminal coil have higher diagnostic accuracy and can delineate the diverticular cavity and help detect related complications. Clinicians should consider the possibility of a urethral diverticulum in women with chronic or recurrent lower urinary tract symptoms. Moreover, because female urethral diverticulum is becoming more prevalent in clinical practice, radiologists should be familiar with its imaging features and with the imaging techniques that are optimal for its evaluation.

Antegrade retrieval of ureteral stents through an 8-French percutaneous nephrostomy route.

OBJECTIVE: The purpose of this study was to describe the technique of antegrade retrieval of ureteral stents under fluoroscopic guidance through an 8-French nephrostomy. MATERIALS AND METHODS: During an 8-year period, we retrieved 26 ureteral stents from 24 patients who were not candidates for retrograde removal or had other conditions precluding use of a retrograde approach. A loop snare or grasping forceps was used to retrieve a ureteral stent in the renal pelvis or calyx or upper ureter through an 8-French vascular sheath with a safety wire in place. A snare catheter advanced into the bladder for retrieval of the bladder end was used in patients in whom retrieval with both a loop snare and a grasping forceps failed. RESULTS: All 26 ureteral stents were successfully retrieved by the antegrade approach. Ten stents were retrieved with a snare alone and nine with a forceps alone. Five stents were retrieved successfully with a forceps after initial failures with snare catheters. Two stents were retrieved with snare catheters advanced into the bladder. The major complication of nephrostomy wound infection occurred in a patient with a urinary tract infection who underwent a one-stage procedure. All minor complications, including pelvic perforation in one patient and blood clot in the renal pelvis in four patients, resolved spontaneously without adverse sequelae. CONCLUSION: Antegrade percutaneous retrieval of a ureteral stent through an 8-French nephrostomy is safe and effective and has a high degree of technical success. It can be used as a routine interventional practice in radiology.

Single-session prolonged alcohol-retention sclerotherapy for large hepatic cysts.

OBJECTIVE: Our purpose was to evaluate the safety and therapeutic efficacy of single-session prolonged alcohol sclerotherapy in treating large hepatic cysts. A therapeutic comparison between 4-hour and 2-hour retention techniques was also studied. MATERIALS AND METHODS: Twenty-seven patients with 31 hepatic cysts were enrolled in this study. Seventeen patients (18 cysts) were treated by alcohol retention for 4 hours (group 1) and 10 patients (13 cysts) for 2 hours (group 2). The mean diameter of the hepatic cysts was 12.4 cm (range, 8-23 cm) with a comparable size range in each group. The sclerosing agent used was 95% alcohol, and the maximum amount was limited to 200 mL. Patients changed position and vital signs were monitored every 10-15 minutes. The blood alcohol concentrations were checked hourly for 5 consecutive hours in the initial nine patients. The nonparametric Mann-Whitney U test was used to compare the difference in characteristics and treatment results of the subjects between these two groups. The level of statistical significance was set at a p value of less than 0.05. RESULTS: All but one patient in group 2 tolerated the entire course of sclerotherapy. The mean aspirated volume and mean injected alcohol volume of the hepatic cysts were 730 mL and 138.3 mL, respectively, in group 1 patients, and 931 mL and 139 mL, respectively, in group 2 patients. The mean maximum blood alcohol concentration was 128.2 mg/dL (range, 60-199 mg/dL) at 3-4 hours after alcohol instillation. The mean posttherapy residual cystic diameter was 2.5 cm (range, 0-6 cm), with an average volume reduction rate of 98.3% and 97.7%, respectively, for patients in group 1 and group 2 after a mean follow-up period of 29.6 months (9-59 months). No statistical differences of the mean reduction rate between the two groups were noted. CONCLUSION: Long retention of the alcohol in a single-injection technique is safe and effective. Two-hour alcohol retention has a comparable efficacy to that of 4-hour retention.

Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation.

OBJECTIVE: We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. MATERIALS AND METHODS: Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patients (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8-10 mm in diameter and 40-80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. RESULTS: No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates (+/-standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69%+/-9 and 88%+/-6, 41%+/-10 and 88%+/-6, 30%+/-10 and 77%+/-10, and 12%+/-8 and 61%+/-13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51%+/-16 and 86%+/-13 vs 45%+/-15 and 73%+/-13 at 6 months, and 25%+/-15 and 71%+/-17 vs 23%+/-17 and 73%+/-13 at 12 months (p = .346 and .224), respectively. CONCLUSION: Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen.

Single-session alcohol-retention sclerotherapy for simple renal cysts: comparison of 2- and 4-hr retention techniques.

OBJECTIVE: The objectives of our study were to evaluate the feasibility of ethanol sclerotherapy in treating simple renal cysts with prolonged ethanol retention and to compare the therapeutic results of 2- and 4-hr retention techniques. MATERIALS AND METHODS: We retrospectively reviewed 36 renal cysts in 33 patients treated by ethanol sclerotherapy with a single-session single-injection technique during the past 6 years. After complete aspiration of the cystic fluid, 95% ethanol was injected into the cyst and was retained for 4 hr in 14 cysts (group 1) and for 2 hr in 22 cysts (group 2). The average maximal diameter and aspirated volume of the cysts were 8.3 cm and 223 mL in group 1 patients and 7.9 cm and 167 mL in group 2, respectively. The ablated cysts were followed up regularly by sonography, CT, or both at 3- to 6-month intervals for at least 1 year. The nonparametric Mann-Whitney U test was used to compare differences in characteristics, treatment results, and laboratory data of the subjects in the two groups. The level of statistical significance was set at a p value of less than 0.05. RESULTS: Technically, all the patients tolerated the procedures. One patient had gross hematuria 10 days after the procedure. She underwent surgical deroofing treatment and was excluded in the later statistical analysis. After sclerotherapy, 14 cysts disappeared completely and 16 cysts showed marked regression with residual maximal diameter of less than 3 cm. The overall volume reduction rate was 97.6% in all 35 cysts. The mean residual longest diameters and average volume reduction rates of the treated cysts were 1.9 cm and 97.9% in group 1 patients and 1.1 cm and 97.3% in group 2 patients, respectively, which showed no statistical significance of volume reduction rate with a p value 0.149. CONCLUSION: The single-session prolonged ethanol-retention technique is safe and efficacious for the treatment of renal cysts. There is no statistical difference in therapeutic efficacy between 2- and 4-hr ethanol-retention techniques.

Metallic stent placement for treating peripheral outflow lesions in native arteriovenous fistula hemodialysis patients after insufficient balloon dilatation.

OBJECTIVE: The purpose of this study was to report our experience with metallic stent placement in the peripheral outflow veins in native arteriovenous fistula (A-V fistula) hemodialysis patients after insufficient balloon dilatation. MATERIALS AND METHODS: During the past 4 years, 12 A-V fistula dialysis patients in our hospital underwent metallic stent placement in the peripheral outflow veins to restore vascular access. The indications for metallic stent placement in our study included (1) recoil stenosis of outflow vein in six patients; (2) outflow venous rupture in two patients and dissection in one patient; and (3) large residual adherent thrombus in outflow aneurysms in three patients with thrombosed (arteriovenous) access. Self-expandable Wallstent or Jostent (Jomed, Abbott Laboratories) of appropriate size (6-10 mm in diameter) was chosen for use in these patients. Kaplan-Meier survival analysis was used to calculate the access patency rates. RESULTS: Twelve patients received stents. Eleven patients (92%) underwent successful dialysis after the procedure. One patient experienced complications due to incorrect positioning of the stent at the anastomotic site, causing flow compromise. The primary patency (+/- standard error) of the vascular access at 3, 6, 12, and 24 months was 92% +/- 8%, 81% +/- 12%, 31% +/- 17%, and 31% +/- 17%, respectively. The secondary patency of the vascular access at 3 months was 92% +/- 8%, and 82% +/- 12% at 6, 12, and 24 months each. CONCLUSION: Metallic stent placement is safe and effective in treating peripheral venous lesions in native A-V fistula hemodialysis patients after unsatisfactory balloon dilatation.