HDR-192Ir intraluminal brachytherapy in treatment of malignant obstructive jaundice

AIM: To determine the feasibility and safety of intraluminal brachytherapy in treatment of malignant obstructive jaundice (MOJ) and to evaluate the clinical effect of intraluminal brachytherapy on stent patency and patient survival. METHODS: Thirty-four patients with MOJ were included in this study. Having biliary stent placed, all patients were classified into intraluminal brachytherapy group (group A, n = 14) and control group (group B, n = 20) according to their own choice. Intraluminal brachytherapy regimen included: HDR-192Ir was used in the therapy, fractional doses of 4-7 Gy were given every 3-6 d for 3-4 times, and standard points were established at 0.5-1.0 cm. Some patients of both groups received transcatheter arterial chemoembolization (TACE) after stent placement. RESULTS: In group A, the success rate of intraluminal brachytherapy was 98.0%, RTOG grade 1 acute radiation morbidity occurred in 3 patients, RTOG/EORTC grade 1 late radiation morbidity occurred in 1 patient. Mean stent patency of group A (12.6 mo) was significantly longer than that of group B (8.3 mo) (P<0.05). There was no significant difference in the mean survival (9.4 mo vs 6.0 mo) between the two groups. CONCLUSION: HDR-192Ir intraluminal brachytherapy is a safe palliative therapy in treating MOJ, and it may prolong stent patency and has the potentiality of extending survival of patients with MOJ.     

Transduodenal intraluminal high dose rate brachytherapy in the treatment of carcinomas of the subhepatic region

BACKGROUND/AIMS: The prognosis of carcinomas of the subhepatic region is poor, and therapeutic efforts are limited mostly to palliation. The aim of this study was to retrospectively evaluate the effectiveness of transduodenal administration of intraluminal high dose rate brachytherapy in the palliative treatment of bile duct and pancreatic head carcinomas. METHODOLOGY: Twelve patients with inoperable bile duct and pancreatic head carcinomas were treated by transduodenal brachytherapy using high dose rate remote afterloading system. Eleven patients were treated by intraluminal brachytherapy inserted via a nasobiliary drain and one patient by intraluminal brachytherapy via a nasopancreatic drain inserted in the duct of Wirsung. RESULTS: After transduodenal intraluminal brachytherapy, a control of icterus was observed in all patients. The treatment was well tolerated with the mean survival of 284 days. CONCLUSIONS: Transduodenal intraluminal brachytherapy is technically feasible. The addition of intraluminal brachytherapy may be beneficial to patients in whom drainage can be established. Transduodenal insertion of brachytherapy is not competitive to the percutaneous approach but spreads the possibilities of the treatment of bile duct carcinoma. Intraluminal brachytherapy of pancreatic head carcinoma is feasible only via transduodenal approach.     

Endoscopic intraluminal brachytherapy and metal stent in malignant hilar biliary obstruction: a pilot study.

BACKGROUND/AIMS: Malignant hilar biliary obstruction carries a poor prognosis, as the disease is often unresectable at the time of diagnosis. Various palliative measures as surgical/radiological/ endoscopic drainage with or without radiotherapy/chemotherapy have been tried with dismal outcome. We prospectively studied the effect of unilateral metal stent with intraluminal high dose rate (HDR) brachytherapy in patients with type II malignant hilar biliary obstruction. METHODS: Eight patients with type II malignant hilar biliary obstruction were treated with contrast-free unilateral metal stenting followed by endoscopic intraluminal brachytherapy (ILBT). A retrospectively analyzed group of 10 patients treated only with contrast-free unilateral metal stenting served as historical controls. RESULTS: A successful drainage was achieved in all, cholangitis occurred in none and no patient died within 30 days in both groups. The mean (+/-SD) patency of metal stent was 305 (+/-183.96) days and 143.9(+/-115.11) days in patients with and without intraluminal brachytherapy, respectively (P=0.03). Mean (+/-SD) survival of these patients was 310 (+/-192.68) days and 154.9 (+/-122.51) days in patients with and without intraluminal brachytherapy, respectively (P=0.05). Kaplan-Meier analysis showed estimated median survival of 225 (95% CI; 169.5, 280.4) days in brachytherapy and 100 (95%CI; 94.1, 105.8) days in control group (P=0.025). No major complications related to metal stent or ILBT were observed. CONCLUSIONS: Contrast-free unilateral metal stenting with HDR ILBT in type II malignant hilar biliary obstruction is a safe and effective method of palliation and appears to prolong patient survival as well as patency of stent in these patients, however, a larger, randomized trial is required to validate the same.     

Intraluminal high dose rate brachytherapy in the treatment of bile duct and gallbladder carcinomas

BACKGROUND/AIMS: The prognosis of biliary tract carcinomas is poor, and therapeutic efforts are limited mostly only to palliation. The aim of this study was to retrospectively evaluate the effectiveness and tolerability of intraluminal high dose rate brachytherapy in the treatment of bile duct and gallbladder carcinomas. METHODOLOGY: Thirteen patients with bile duct and gallbladder carcinomas were treated by brachytherapy administered through high dose rate remote afterloading system. Five patients after Roux-en-Y hepaticojejunoanastomosis were treated by intraluminal brachytherapy inserted via a diahepatal drain, and 8 inoperable patients were treated by intraluminal brachytherapy via a percutaneous biliary drain. RESULTS: After intraluminal brachytherapy, a control of icterus was observed in all patients. The treatment was well tolerated and mean survival was 275 days. CONCLUSIONS: The addition of intraluminal brachytherapy may be beneficial to patients with carcinomas causing biliary obstruction in whom bile drainage can be established.     

Adjuvant therapies using biliary stenting for malignant biliary obstruction

The aim of this study was to analyze the patency of expandable metallic stents in malignant biliary obstruction and to evaluate the efficacy of adjuvant therapy accompanied by biliary stenting. We analyzed 29 patients in whom bile duct stenting was performed for malignant biliary obstruction. Their types of disease were: hilar ductal carcinoma (n = 8), gallbladder carcinoma (n = 11), and pancreatic carcinoma (n = 10). Initially, 46 expandable metallic stents were placed in 29 patients. In 23 of the 29 patients, adjuvant therapy was administered. Seventeen patients underwent radiotherapy, and 16 patients received various systemic chemotherapies. In principle, hyperthermia was performed twice a week, simultaneously with radiotherapy. Patient survival and the probability of stent patency were calculated using actuarial life table analysis. There was no significant difference in stent patency among the patients according to type of disease. Hyperthermia did not influence the stent patency rate. The median stent patency time was significantly greater in the chemo-radiation group than in the no-adjuvant therapy group: 182 days versus 68 days, respectively (P = 0.017). Moreover, a significant increase was seen in the median survival time in the chemo-radiation group: 261 days versus 109 days (P = 0.0337). Complications occurred in 9 patients (31.0%). Stent occlusion occurred in 6 patients (20.7%), with all of these patients managed successfully using a transhepatically placed new expandable metallic stent, employing the stent-in-stent method. Stent migration occurred in 2 patients after radiotherapy. Adjuvant therapies such as radiotherapy and systemic chemotherapy, in combination with stent insertion, resulted in an increase in the patency period of expandable metallic stents and in increased patient survival time.     

Evaluation of covered metallic stents in malignant biliary stenosis--prominent effectiveness in gallbladder carcinoma

BACKGROUND/AIMS: The survival time of patients with unresectable malignant biliary stenosis and the patent period of metallic biliary stents are different in each disease. The efficacy of the covered metallic stent was analyzed according to the primary disease. METHODOLOGY: Seventy-three patients with bile duct carcinoma (12 cases), gallbladder carcinoma (22 cases), and pancreas carcinoma (39 cases) were retrospectively enrolled. Covered metallic stents were used in 42 patients and uncovered metallic stents in 31 patients. The patency of covered stents was compared with that of uncovered stents for each disease. RESULTS: The patent rate at 6 months after insertion was 80.6% (95% CI [72.6%, 88.6%]) for the covered stent, and 49.5% (95% CI [37.6%, 61.4%]) for the uncovered stent. The mean patent periods of the covered stent and the uncovered stent were 14.6 and 27.6 months for bile duct carcinoma (p=0.424), 12.7 and 3.0 months for gallbladder carcinoma (p=0.003), and 11.9 and 9.6 months for pancreas carcinoma (p=0.919), respectively. CONCLUSIONS: The covered metallic stent was the most effective in patients with gallbladder carcinoma.     

Cryotherapy, electrocautery, and brachytherapy

Since it was first used 70 years ago, brachytherapy has become an effective tool in the treatment with tracheal bronchial malignancy including primary and recurrent bronchogenic carcinoma and metastatic carcinoma. The technique has evolved from interstitial implantation of radioactive sources directly to the tumor using rigid bronchoscopy to intraluminal placement of a radioactive source into a polyethylene afterloading catheter placed using FB. Intraluminal brachytherapy is effective in palliating complications caused by malignant endobronchial tumors such as dyspnea, hemoptysis, intractable cough, atelectasis, and postobstructive pneumonia. Brachytherapy may be combined with external beam radiation, Nd:YAG laser therapy, and chemotherapy to enhance the palliative treatments of patients. The risk of severe complications from brachytherapy may be caused more by location of tumor being treated rather than those fractionations scheme. When tumor involves the mainstem bronchi and upper lobes, it seems prudent to obtain CT to exclude tumor invasion of the pulmonary arteries or considerable destruction of the bronchial wall and mediastinal invasion of the tumor. Patients with findings such as these should not be treated with endobronchial brachytherapy or treated with LDR brachytherapy. Brachytherapy is proved to be effective and a safe palliative treatment for endobronchial malignancies, but further investigations are necessary to determine the optimal dose scheme and its efficiency in bronchogenic carcinoma and combined with external beam radiation therapy or surgery or other endobronchial procedures such as Nd:YAG laser or cryotherapy.     

Endoscopic palliation of patients with biliary obstruction caused by nonresectable hilar cholangiocarcinoma: efficacy of self-expandable metallic Wallstents

BACKGROUND: The aim of this study was to evaluate the efficacy of an endoscopically inserted self-expandable metal stent for treatment of biliary obstruction caused by nonresectable hilar cholangiocarcinoma. METHODS: Data on all patients with nonresectable hilar cholangiocarcinoma receiving self-expandable metal stents between January 1990 and April 2000 were retrospectively reviewed. Patients with pseudo Klatskin tumors (metastases in the liver hilum) and gallbladder carcinoma were excluded. Early complications (within 30 days of stent placement), early and late stent occlusion, stent patency, and biliary reintervention rates were recorded. RESULTS: Fifty-two Wallstents were inserted in 36 patients, with 7, 13, and 16 having, respectively, Bismuth type I/II, III, and IV lesions. Insertion was successful in 35 of 36 (97%) patients. Complications occurred within the first 30 days after insertion in 5 patients (14%) but did not require biliary reintervention. Thirty-day mortality was 6% (2 deaths). There were 3 early (9%) and 8 late (23%) stent occlusions, bringing the total to 11 patients (31%) who required biliary reintervention after Wallstent insertion. Median Wallstent patency and patient survival were, respectively, 169 days (95% CI [154, 184]) and 147 days (95% CI [106, 188]), with no difference between patients with Bismuth I/II, III, IV type tumors. CONCLUSIONS: Wallstent insertion is safe and feasible, and achieves successful palliation without the need for further biliary reintervention in the majority (69%) of patients with nonresectable hilar cholangiocarcinoma.     

Treatment of malignant biliary obstruction by combined percutaneous transhepatic biliary drainage with local tumor treatment

AIM: To evaluate the utility of local tumor therapy combined with percutaneous transhepatic biliary drainage (PTBD) for malignant obstructive biliary disease. METHODS: A total of 233 patients with malignant biliary obstruction were treated in our hospital with PTBD by placement of metallic stents and/or plastic tubes. After PTBD, 49 patients accepted brachytherapy or extra-radiation therapy or arterial infusion chemotherapy. The patients were followed up with clinical and radiographic evaluation. The survival and stent patency rate were calculated by Kaplan-Meier survival analysis. RESULTS: Twenty-two patients underwent chemotherapy (11 cases of hepatic carcinoma, 7 cases of pancreatic carcinoma, 4 cases of metastatic lymphadenopathy), and 14 patients received radiotherapy (10 cases of cholan-giocarcinoma, 4 cases of pancreatic carcinoma), and 13 patients accepted brachytherapy (7 cases of cholangio-carcinoma, 3 cases of pancreatic carcinoma, 4 cases of metastatic lymphadenopathy). The survival rate of the local tumor treatment group at 1, 3, 6, and 12 months was 97.96%, 95.92%, 89.80%, and 32.59% respectively, longer than that of the non treatment group. The patency rate at 1, 3, 6, and 12 months was 97.96%, 93.86%, 80.93%, and 56.52% respectively. The difference of patency rate was not significant between treatment group and non treatment group. CONCLUSION: Our results suggest that local tumor therapy could prolong the survival time of patients with malignant biliary obstruction, and may improve stent patency.     

Intraluminal high dose rate brachytherapy of tumorous esophageal stenoses

BACKGROUND/AIMS: The prognosis of inoperable carcinomas of esophagus is poor, and therapeutic efforts are generally limited to palliation. The aim of this study was to retrospectively evaluate the effectiveness of intraluminal high dose rate brachytherapy in the palliative treatment of tumorous esophageal stenoses. METHODOLOGY: Between February 1997 and July 2002 intraluminal brachytherapy was performed in 19 patients with inoperable esophageal carcinoma (squamous cell carcinoma in 14 cases and adenocarcinoma in 5 cases). All patients had dysphagia at presentation. Brachytherapy was performed using high dose rate afterloading system. RESULTS: Dysphagia was improved in all patients. The mean survival was 248 days. No mechanical complications were observed during introduction of the applicator. CONCLUSIONS: Our experience indicates that intraluminal brachytherapy is an effective and safe method of palliation of dysphagia caused by malignant esophageal stenosis.     

Transpapillary iridium-192 wire in the treatment of malignant bile duct obstruction.

Twenty four patients with malignant bile duct obstruction were treated with intraluminal radiotherapy using iridium-192 wire inserted through an endoscopically placed nasobiliary catheter. Biliary drainage after treatment was maintained by an endoprosthesis. The median dose of intraluminal radiotherapy was 6000 cGy; two patients with cholangiocarcinoma were given a second course because of disease extension; four patients with pancreatic carcinoma received additional external irradiation (3000 cGy). There was one early death from a cerebrovascular accident (30 day mortality, 4.2%). Cholangitis (30%) was the major early complication and stent blockage (40%) the major late complication; there were no complications directly attributable to radiotherapy. The median survival for patients with pancreatic carcinoma was 250 days and for cholangiocarcinoma, 300 days. This method is technically feasible and may prove safer than the transhepatic technique. The ability of intraluminal irradiation to improve palliation or lengthen survival in patients with malignant bile duct obstruction remains uncertain. Assessment by a prospective, controlled trial is essential.     

Unilateral placement of metallic stents for malignant hilar obstruction: a prospective study

BACKGROUND: Palliation of patients with malignant hilar stenoses, especially advanced lesions, by stent insertion poses particular difficulties. This study assessed the efficacy of endoscopically inserted unilateral metallic stents for complex malignant hilar obstruction. METHODS: A prospective, uncontrolled, single-center study was conducted by using a cohort of 61 patients with malignant hilar obstruction. A single, unilateral metallic stent was inserted across the stricture into the duct that technically was easiest to access. Patients were evaluated 1 month after stent placement and, thereafter, every 3 months. RESULTS: Successful stent insertion was achieved in 59 of 61 (96.7%) patients. In 3 of 61 (4.9%) cases, stent malfunction occurred. Successful drainage was achieved in 59 of 61 (96.7%) patients and complete resolution of jaundice in 86% of cases. Early complications included cholangitis in 3 of 61 (4.9%) patients and stent occlusion in 2 of 61 (3.2%). Late stent occlusion occurred in 14 of 61 (22.9%) patients, including 10 (16.3%) cases of cholangitis and one of liver abscess. Median stent patency was 169 days. Median patient survival was 140 days. CONCLUSIONS: Unilateral metallic stent insertion is safe, feasible, and achieves adequate drainage in the great majority of patients with nonresectable hilar cholangiocarcinoma.     

Treatment of malignant digestive tract obstruction by combined intraluminal stent installation and intra-arterial drug infusion

AIM: To study the palliative treatment of malignant obstruction of digestive tract with placement of intraluminal stent combined with intra-arterial infusion of chemotherapeutic drugs. METHODS: A total of 281 cases of digestive tract malignant obstruction were given per oral (esophagus, stomach, duodenum and jejunum), per anal (colon and rectum) and percutaneous transhepatic (biliary) installation of metallic stent. Among them, 203 cases received drug infusion by cannulation of tumor supplying artery with Seldinger's technique. RESULTS: Altogether 350 stents were installed in 281 cases, obstructive symptoms were relieved or ameliorated after installation. Occurrence of restenotic obstruction was 8-43 weeks among those with intra-arterial drug infusion, which was later than 4-26 weeks in the group with only stent installation. The average survival time of the former group was 43 (3-105) weeks, which was significantly longer than 13 (3-24) weeks of the latter group. CONCLUSION: Intraluminal placement of stent combined with intra-arterial infusion chemotherapy is one of the effective palliative therapies for malignant obstruction of the digestive tract with symptomatic as well as etiological treatment.     

Palliative treatment of malignant esophageal stenosis: the role of self-expanding stent endoscopic implantation

Endoscopic tube implantations were carried out in 40 patients with malignant stenosis of the esophagus and gastric cardia using self-expanding metallic stents. The indications for endoscopic intubation were the advanced stage of the tumor in 27 cases and risk factors that made resection inadvisable in 13 cases. In three patients, it proved impossible to implant a stent endoscopically because we were not able to pass the guide wire through the stenosis, whereas correct stent placement was achieved in 37 cases. Functional results were good in 33 patients, but four patients did not show any improvement of symptoms. Complications occurred in nine patients (24.3%): two bleedings, three neoplastic obstructions, one food obstruction, and three distal dislodgements of the prosthesis were observed, but could be readily corrected. No deaths occurred. The median survival time was 151 days (range 25-545 days). This study suggests that endoscopic placement of metallic self-expanding stents is safe and is to be preferred to plastic stents for easier implantation and lower morbidity.     

Relief of jaundice by external beam radiotherapy and intraluminal brachytherapy in patients with extrahepatic cholangiocarcinoma: results without stenting

BACKGROUND/AIMS: To clarify whether external beam radiotherapy combined with intraluminal brachytherapy without stenting provides long-term relief of jaundice in extrahepatic cholangiocarcinoma patients. METHODOLOGY: Twenty-five patients with unresectable hilar or distal cholangiocarcinoma were treated by external beam radiotherapy (30 or 50 Gy) combined with intraluminal brachytherapy (24 to 40 Gy). After radiotherapy, we removed the biliary drainage tubes from the patients who responded, and we did not perform stenting in these patients. RESULTS: In 19 (76%) patients, full patency was achieved at the treated lesion, and they were tube-free thereafter. The tube-free survival time in the 19 patients ranged from 7 to 468 days (median: 76 days). Cholangitis and gastroduodenal ulcer developed in 10 (40%) and 2 (8%) patients, respectively, as adverse events after the combined radiotherapy. The median survival time of all patients was 9.3 months, and their 6- and 12-month survival rates were 75.3% and 29.3%, respectively. The ratios of tube-free to overall survival in the 19 patients ranged from 2.4% to 79.4% (median: 26.8%). Eight patients died tube-free. CONCLUSIONS: Although there were limitations to the long-term relief of jaundice by this combined radiotherapy alone, tube-free status was achieved in some patients without stenting.     

Palliative therapy in cholangio- and gallbladder carcinoma

Non-resectable cholangiocarcinoma and gallbladder carcinoma have a poor prognosis. In addition to the general aspects of "best supportive care", biliary drainage is an important part of the palliative treatment of patients with malignant biliary stenosis. Photodynamic therapy has led to an improved median survival in hilar cholangiocarcinoma in two controlled studies. The survival benefit of external radiation or intraluminal brachytherapy has not yet been convincingly demonstrated. Whether or not systemic chemotherapy should be applied is still under debate. A single study including advanced biliary and pancreatic cancer patients has demonstrated a survival benefit for the combined group. In recent years, new chemotherapy protocols have been applied, some with promising results. Intra-arterial chemotherapy and chemotherapeutically coated stents have not been evaluated well enough to be recommended outside clinical studies. Ablative therapies have been used in a limited number of patients only. Further studies are necessary to clarify whether these treatment modalities are effective.     

Combined stent insertion and single high-dose brachytherapy in patients with advanced esophageal cancer--results of a prospective safety study

Previous randomized studies comparing the two commonly used palliative treatments for incurable esophageal cancer, i.e. stent insertion and intraluminal brachytherapy, have revealed the pros and cons of each therapy. While stent treatment offers a more prompt effect, brachytherapy results in more long-lasting relief of dysphagia and a better health-related quality of life (HRQL) in those living longer. This prospective pilot study aimed to explore the feasibility and safety of combining these two regimes and incorporating a single high dose of internal radiation. Patients with newly diagnosed, incurable cancer of the esophagus and dysphagia were eligible for inclusion, and stent insertion followed by a single dose (12 Gy) of brachytherapy was performed as a two-stage procedure. Clinical parameters including HRQL and adverse events were registered at inclusion, and 1, 2, 3, 6, and 12 months later. Twelve patients (nine males) with a median age of 73 years (range 54-85) were included. Stent insertion followed by a single dose of brachytherapy was successfully performed in all but one patient who was treated with stent only. Relief of dysphagia was achieved in the majority of cases (10/11, P < 0.05), but HRQL did not improve except for dysphagia-related items. Only minor adverse events, including chest pain, reflux, and restenosis, were reported. The median survival time after inclusion was 6.6 months. Our conclusion is that the combination of stent insertion and single high-dose brachytherapy seems to be a feasible and safe palliative regime in patients with advanced esophageal cancer. Randomized trials comparing the efficacy of this strategy to stent insertion or brachytherapy alone are warranted.     

Microwave coagulation versus insertion of a second stent for occluded biliary metal stent.

BACKGROUND/AIMS: There is no consensus regarding optimal management of self-expandable metallic stent occlusion. We investigated the efficacy of microwave coagulation therapy for recanalization as compared to second stent placement. METHODOLOGY: Sixty patients with malignant obstruction of the common bile duct were treated with metal stent placement from January 1992 to July 1999. Of these, 13 patients subsequently developed stent occlusion due to tumor ingrowth. We compared stent patency and patient survival rates after microwave coagulation to those after insertion of a second stent. The influence of the duration of patency of the first stent on the second stent patency was also evaluated. RESULTS: Of the 13 patients with stent occlusion, 7 were treated with microwave coagulation therapy, and 6 with insertion of a second metal stent. In all cases, occluded stents were successfully recanalized without any complications. There was no significant difference in duration of first stent patency between the two groups. The median duration of second stent patency was prolonged in microwave-treated patients (152 days vs. 104 days, P > 0.05). The median duration of patient survival after last recanalizing procedure was also prolonged in microwave-treated patients (131 days vs. 78 days, P > 0.05). Microwave energy did not induce destruction of the stent filament. CONCLUSIONS: Microwave coagulation did not offer significantly longer duration of stent patency and patient survival compared to insertion of a second metal stent. However, this procedure is safe, feasible, and certainly as good as a second stent placement. It may be an alternative to insertion of a second stent within the occluded stent.     

Stent placement or brachytherapy for palliation of dysphagia from esophageal cancer: a prognostic model to guide treatment selection

BACKGROUND: Brachytherapy was found to be preferable to metal stent placement for the palliation of dysphagia because of inoperable esophageal cancer in the randomized SIREC trial. The benefit of brachytherapy, however, only occurred after a relatively long survival. The objective is to develop a model that distinguishes patients with a poor prognosis from those with a relatively good prognosis. METHODS: Survival was analyzed with Cox regression analysis. Dysphagia-adjusted survival (alive with no or mild dysphagia) was studied with Kaplan-Meier analysis. Patient data is from the multicenter, randomized, controlled trial (SIREC, n = 209) and a consecutive series (n = 396). Patients received a stent or single-dose brachytherapy. RESULTS: Significant prognostic factors for survival included tumor length, World Health Organization performance score, and the presence of metastases (multivariable p < 0.001). A simple score, which also included age and gender, could satisfactorily separate patients with a poor, intermediate, and relatively good prognosis within the SIREC trial. For the poor prognosis group, the difference in dysphagia-adjusted survival was 23 days in favor of stent placement compared with brachytherapy (77 vs. 54 days, p = 0.16). For the other prognostic groups, brachytherapy resulted in a better dysphagia-adjusted survival. CONCLUSIONS: A simple prognostic score may help to identify patients with a poor prognosis in whom stent placement is at least equivalent to brachytherapy. If further validated, this score can provide an evidence-based tool for the selection of palliative treatment in esophageal cancer patients.     

Intravascular ultrasound characterization of the "black hole" phenomenon after drug-eluting stent implantation

An intraluminal echolucent tissue, dubbed "black hole," has been identified by intravascular ultrasonography after intracoronary brachytherapy. This study reports the characteristics and incidence of the black hole in patients treated with drug-eluting stent implantation using a sirolimus-eluting stent (SES). We included intravascular ultrasound data from the Compassionate Use of Sirolimus-Eluting Stent (SECURE, n = 61 lesions) registry, a study involving patients in whom previous brachytherapy had failed, and the DIABETES trial (n = 165 lesions), a multicenter, randomized study comparing SES versus bare metal stents in diabetic patients. Intravascular ultrasound follow-up was scheduled at 8 months (SECURE trial, post-brachytherapy population) and 9 months (DIABETES trial). In the SECURE population, a black hole was observed in 10 patients (19.6%). Seven black hole segments had significant intimal hyperplasia (> 10%). A black hole accounted for 27% of total intraluminal tissue. In the DIABETES trial, 2 patients (2.5%) in the SES group and none in the bare metal stent group showed echolucent intimal hyperplasia. In conclusion, a black hole occurred frequently after implantation of a SES in patients in whom intracoronary brachytherapy had previously failed. Black holes were also identified in a nonirradiated population, although the incidence was lower than in the post-brachytherapy patients. Bare metal stents were not associated with this phenomenon.