Yong-Dong Li

Large-Cohort Comparison Between Three-Dimensional Time-of-Flight Magnetic Resonance and Rotational Digital Subtraction Angiographies in Intracranial Aneurysm Detection

Background and Purpose— The value of MR angiography varies in diagnosis of intracranial aneurysms due to the difference of equipment and imaging technique. This study was to compare the effectiveness of 3-dimensional time-of-flight MR angiography at 3 T and rotational digital subtraction angiography, both with volume rendering (VR), in detecting intracranial aneurysms. Methods— One hundred thirty-eight patients with suspected or known aneurysms and other cerebral vascular diseases detected by MR angiography underwent digital subtraction angiography examinations. Postprocessing techniques, including VR and the single artery highlighting method, were performed by a 3-dimensional specialist. The VR-digital subtraction angiography was obtained as the gold standard. Results— The rotational digital subtraction angiography and VR-digital subtraction angiography revealed 146 aneurysms in 122 patients and no aneurysms in 16 patients. Of the 276 vessels examined, 136 vessels had 146 aneurysms and 140 vessels had none. Per vessel and per aneurysm sensitivities were 100%, whereas the per vessel accuracy ranged from 97.5% to 98.6% and the per aneurysm accuracy ranged from 95.1% to 97.0%. Conclusions— VR 3-dimensional time-of-flight MR angiography at 3 T has excellent sensitivity, accuracy, and correlation with VR-digital subtraction angiography and is comparable to catheter cerebral angiography for the evaluation of patients with intracranial aneurysms who tolerate MR angiography well.

Endovascular treatment of post-traumatic direct carotid-cavernous fistulas: A single-center experience

We report our single-center experience using detachable balloons (DB), coils and Willis covered stents (MicroPort, Shanghai, China) to treat post-traumatic direct carotid-cavernous fistulas (DCCFs), focusing on preservation of the internal carotid artery (ICA). We retrospectively reviewed the records of 51 patients who received endovascular treatment (EVT). EVT with DBs was chosen as the first-line therapeutic strategy, and Willis covered stent placement and coiling was the alternative. The patency and stability of all DCCFs was evaluated by angiographic and clinical follow-up for between 3 and 48 months. A total of 54 DCCFs in 51 patients were treated as follows: DB alone (n=40); combined DB and Willis covered stent (n=8); Willis covered stent alone (n=2); combined DB and coils (n=2); coils alone (n=1); and DB in combination with both coils and a Willis covered stent (n=1). Overall, 98% of DCCFs were successfully treated with the occlusion of the fistula and preservation of the ICA; the ICA was sacrificed in only one patient. Approximately 85% of DCCFs were successfully treated with DBs alone. Second and third administrations of EVT were required in 12 DCCFs. DCCF-related symptoms improved gradually between 1 day and 6 months after treatment. EVT using DB to occlude fistulas and preserve the ICA is the preferential treatment for DCCFs. When standard treatment has failed, coils and/or Willis covered stents can be used as a safe alternative or remedial tool with ICA preservation and reconstruction.

Accurate Diagnosis of Small Cerebral Aneurysms ≤5 mm in Diameter with 3.0-T MR Angiography

PURPOSE To evaluate the diagnostic accuracy of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography at 3.0 T in the detection of small cerebral aneurysms. MATERIALS AND METHODS The institutional review board approved the study protocol, and patients or qualifying family members provided informed consent. A total of 403 consecutive patients undergoing 3D TOF MR angiography and digital subtraction angiography (DSA) were prospectively enrolled. Small aneurysms were those 5 mm in diameter or smaller. DSA served as the reference standard. Three observers were blinded to clinical and DSA results, and they independently analyzed all 3D TOF MR angiographic data sets. Interobserver agreement was expressed in terms of Cohen κ value for categorical variables. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 3D TOF MR angiography in the detection of cerebral aneurysms were determined by using patient-, aneurysm-, and location-based evaluations. RESULTS Of 403 patients, 273 aneurysms were detected with DSA in 230 patients. Patient-based evaluation with 3D TOF MR angiography at 3.0 T yielded an accuracy of 96%-97%, a sensitivity of 98.2%-98.7%, a specificity of 93.2% -94.8%, a PPV of 94.9%-96.2%, and an NPV of 97.6%-98.2% in the detection of cerebral aneurysms. Aneurysm-based evaluation yielded an accuracy of 96.4%-97.3%, a sensitivity of 98.5%-98.9%, a specificity of 93.2%-94.9%, a PPV of 95.7%-96.8%, and an NPV of 97.6%-98.2%. Aneurysm-location evaluations yielded similar results. CONCLUSION Three-dimensional TOF MR angiography is a noninvasive method that shows promising diagnostic accuracy in the detection of small cerebral aneurysms.

13-Year Follow-Up of a Prospective Comparison of the Long-Term Clinical Efficacy of Temporary Self-Expanding Metallic Stents and Pneumatic Dilatation for the Treatment of Achalasia in 120 Patients

OBJECTIVE The purpose of this article is to compare the efficacy of self-expanding metallic stents and pneumatic dilation for the long-term clinical treatment of achalasia. SUBJECTS AND METHODS Patients diagnosed with achalasia (n = 120) were allocated for treatment with pneumatic dilation (n = 30; group A) or a temporary self-expanding metallic stent with a diameter of 20 mm (n = 30; group B), 25 mm (n = 30; group C), or 30 mm (n = 30; group D). Data on clinical symptoms, complications, and long-term clinical outcomes were collected, and follow-up was performed at 6 months and at 1, 3-5, 5-8, 8-10, and more than 10 years after surgery. RESULTS Pneumatic dilation and stent placement were technically successful in all patients. The follow-up at more than 10 years revealed that the clinical remission rate in group D (83.3%) was higher than that in groups A (0%), B (0%), and C (28.6%), and the overall cumulative clinical failure rate in group D (13%) was lower than that in groups A (76.7%), B (53.3%), and C (26.7%). Patients in group D exhibited reduced dysphagia scores and lower esophageal sphincter pressures and had normal levels of barium height and width during the follow-up periods, whereas these markers increased with time in the other groups. The duration of primary patency in group D was also longer than that in groups A, B, and C. CONCLUSION A temporary self-expanding metallic stent with a diameter of 30 mm has superior clinical efficacy for the treatment of achalasia compared with pneumatic dilation or self-expanding metallic stents with diameters of 20 or 25 mm.

Prevention and management of intraprocedural rupture of intracranial aneurysm with detachable coils during embolization

IntroductionIntracranial aneurysm rupture during embolization with detachable coils is reportedly among the gravest of intraprocedural complications. We present here our experiences with this outcome, and a potential intervention for managing this life-threatening complication.MethodsFrom April 1998 to March 2005, 284 patients with cerebral aneurysms were treated with detachable coils. Intraprocedural aneurysm rupture occurred in ten patients with a history of a previously ruptured aneurysm. In the event of intraprocedural hemorrhage, we routinely performed heparin reversal with protamine sulfate.ResultsOf the 221 patients with a previously ruptured aneurysm, intraprocedural aneurysm rupture occurred in 10 (4.5%). These ruptures were caused by a microguidewire in one patient, a microcatheter in one, over-packing in two and a coil perforation in three. In the remaining three patients the ruptures were caused by both the microcatheter and the coils. Three patients died because of aneurysm re-rupture, yielding a mortality rate of 30%. One patient presented with a slight disability in the left leg and no neurological deficits were observed in the remaining six patients.ConclusionIntraprocedural aneurysm rupture during embolization is a rare, but unavoidable and life-threatening event. Proper measures should be taken to reduce and improve the outcome of this tragic occurrence. The majority of patients with an intraprocedural ruptured aneurysm can survive without severe sequelae if managed appropriately.

Management of pseudoaneurysms in the intracranial segment of the internal carotid artery with covered stents specially designed for use in the intracranial vasculature: technical notes.

Vascular diseases like aneurysms, pseudoaneurysms and direct high-flow carotid-cavernous fistulas on the intracranial segment of the internal carotid artery are usually managed through transarterial embolization with detachable coils or balloons. Utility of covered stents has been reported with good results in the treatment of selective cases. But the current generation of covered stents for coronary use is rather stiff and difficult to navigate in tortuous vessels particularly in the intracranial vasculature. Herein, we report on the use and technical respects of balloon-expanded covered stents specially designed for intracranial vasculature in the treatment of two pseudoaneurysms secondary to the successful obliteration of direct CCFs on the intracranial segment of the internal carotid artery. This is the first report of covered stents specially developed for use in intracranial vasculature.

Endovascular Reconstruction with the Willis Covered Stent for the Treatment of Large or Giant Intracranial Aneurysms

Background: The purpose of this study was to evaluate the feasibility, safety and efficacy of endovascular treatment of large or giant intracranial aneurysms with the Willis covered stent. Methods: Nineteen patients, each with a large or giant intracranial aneurysm, were treated with the Willis covered stent. Of these 19 aneurysms, 6 were giant and 13 were large; 18 were located in the cranial internal carotid artery and 1 in the vertebral artery. Results of the procedure, technical events and complications were recorded. Clinical and imaging follow-ups were performed at 3 and 6–12 months after the procedure. Results: Placement of Willis covered stent was successful in all patients. Complete aneurysm exclusion was achieved in 13 of the 19 aneurysms immediately after the procedure. No mortality or morbidity developed during the treatment or the follow-up period. During the follow-up period, complete aneurysm exclusion was achieved in 18 of the 19 patients; 11 aneurysms were totally involuted, 3 decreased to 25% of the original diameter, 4 decreased to 50% and 1 remained unchanged. Nine patients experienced full recovery, 9 improved and 1 was unchanged. No obvious in-stent stenosis was noted. Conclusions: Endovascular treatment of large or giant intracranial aneurysm with the Willis covered stent is feasible, safe and efficacious in selected cases. Endoleak is a frequent issue after initial covered stent placement, but can be eliminated or dramatically reduced to minimal endoleak by additional covered stent placement and/or balloon reinflation. Minor endoleak is likely to spontaneously resolve over time.

Treatment of traumatic internal carotid artery pseudoaneurysms with the Willis covered stent: a prospective study.

PURPOSE To evaluate the efficacy of the Willis covered stent in the treatment of traumatic pseudoaneurysms of the internal carotid artery (ICA). MATERIALS Thirty-eight patients with traumatic head and neck injury underwent angiography. We evaluated 14 delayed pseudoaneurysms in 13 patients who underwent angiography after treatment with the Willis covered stent. Prospective data on the technical success, initial and final angiographic results, mortality, morbidity, and final clinical outcome were analyzed immediately after the procedure, at the time of discharge from the hospital, at 3 months, 6 months, and 12 months after the procedures, and yearly thereafter. RESULTS The Willis covered stent placement was successful in all 14 pseudoaneurysms. The initial angiographic results showed complete exclusion in 9 patients with 10 aneurysms (71.4% [95% confidence interval {CI}: 44-98%]) and incomplete exclusion in 4 patients. The angiographic follow-up (mean, 15 months [95% CI: 9-20 months]; range, 3-36 months) findings exhibited a complete exclusion in 12 patients with 13 aneurysms (92.9% [95% CI: 77-108%]) and an incomplete exclusion in 1 patient and maintained patency of the ICA in all patients. The clinical follow-up (mean, 20 months [95% CI: 14-27 months]) findings demonstrated full recovery (11 patients), symptom improvement (1 patient), or no change in the symptoms (1 patient). No procedure-related complications or deaths occurred during follow-up. CONCLUSION Treatment with the Willis covered stent provides a viable approach for patients with traumatic pseudoaneurysms of the ICA, maintaining patency of the ICA and thus leading to excellent clinical results. An expanded clinical experiences and a larger sample are needed.

Monitoring Pancreatic Carcinogenesis by the Molecular Imaging of Cathepsin E In Vivo Using Confocal Laser Endomicroscopy

The monitoring of pancreatic ductal adenocarcinoma (PDAC) in high-risk populations is essential. Cathepsin E (CTSE) is specifically and highly expressed in PDAC and pancreatic intraepithelial neoplasias (PanINs), and its expression gradually increases along with disease progression. In this study, we first established an in situ 7,12-dimethyl-1,2-benzanthracene (DMBA)-induced rat model for PanINs and PDAC and then confirmed that tumorigenesis properties in this model were consistent with those of human PDAC in that CTSE expression gradually increased with tumor development using histology and immunohistochemistry. Then, using in vivo imaging of heterotopically implanted tumors generated from CTSE- overexpressing cells (PANC-1-CTSE) in nude mice and in vitro imaging of PanINs and PDAC in DMBA-induced rats, the specificity of the synthesized CTSE-activatable probe was verified. Quantitative determination identified that the fluorescence signal ratio of pancreatic tumor to normal pancreas gradually increased in association with progressive pathological grades, with the exception of no significant difference between PanIN-II and PanIN-III grades. Finally, we monitored pancreatic carcinogenesis in vivo using confocal laser endomicroscopy (CLE) in combination with the CTSE-activatable probe. A prospective double-blind control study was performed to evaluate the accuracy of this method in diagnosing PDAC and PanINs of all grades (>82.7%). This allowed us to establish effective diagnostic criteria for CLE in PDAC and PanINs to facilitate the monitoring of PDAC in high-risk populations.

Management of acute malignant colorectal obstruction with a novel self-expanding metallic stent as a bridge to surgery.

PURPOSE To prospectively evaluate the safety and clinical efficacy of a newly designed self-expandable metallic stent (SEMS) in the treatment of patients with acute malignant colorectal obstruction. METHODS Between April 2001 and October 2007, 52 patients with acute malignant colorectal obstruction were treated with a new designed SEMS as an investigational bridge to surgery. Patients were prospectively followed and relevant data collection was collected, including details regarding technique, clinical symptoms, complications, need for elective surgery, and overall survival. RESULTS Stent placement was technically successful in all but two patients (due to complete obstruction) with no procedure-related complications. Complications included stent migration (n=4), anal pain (n=2) and stool impaction (n=1). Clinical success was achieved in 49 (98%) of 50 patients with resolution of bowel obstruction within 2 days of stent placement. In one patient with stool impaction 2 days after stent placement, endoscopic disimpaction was successfully performed. An elective one-stage surgical procedure was performed in all 50 patients who successfully received a SEMS as a bridge to surgery within a mean of 8+/-2 days (range: 4-11 days) after stent placement. Mean follow-up time was 36+/-12 months (range 3-70 months), and all patients remained alive at the time of this report. CONCLUSION The newly designed SEMS placement as a bridge to surgery was a safe and effective intervention for colonic decompression in patients with acute malignant colorectal obstruction and allowed a high proportion of patients to be successfully proceeded to elective surgery.