Percutaneous mesocaval shunt creation for portal thrombosis in a patient with a JAK2V617F mutation

Myeloproliferative neoplasms (MPN) are the most common cause of noncirrhotic, nontumoral portal vein thrombosis (PVT). Over 90 % of MPN patients with PVT carry the JAK2V617F mutation. Compared to other etiologies of PVT, patients with JAK2V617F MPNs are at increased risk of developing significant portal hypertension. However, when these patients develop refractory portal hypertensive complications requiring portosystemic shunt placement, they have limited options. Transjugular intrahepatic portosystemic shunt (TIPS) insertion is often not feasible, as these patients tend to have extensive, occlusive portal thrombus with cavernous transformation. Surgical portosystemic shunt creation can be an alternative; however, this is associated with significant mortality. In this report, we describe the novel use of a percutaneous mesocaval shunt for successful portomesenteric decompression in a patient with portal hypertension from PVT associated with JAK2V617F positive essential thrombocythemia.

Impact of the COVID-19 Pandemic on Liver Cancer Staging at a Multidisciplinary Liver Cancer Clinic

To compare liver cancer resectability rates before and during the COVID-19 pandemic.

Background

Liver cancers usually present with nonspecific symptoms or are diagnosed through screening programs for at-risk patients, and early detection can improve patient outcomes. In 2020, the COVID-19 pandemic upended medical care across all specialties, but whether the pandemic was associated with delays in liver cancer diagnosis is not known.

Methods

We performed a retrospective review of all patients evaluated at the Johns Hopkins Multidisciplinary Liver Cancer Clinic from January 2019 to June 2021 with a new diagnosis of suspected or confirmed hepatocellular carcinoma (HCC) or biliary tract cancer (BTC).

Results

There were 456 liver cancer patients (258 HCC and 198 BTC). From January 2019 to March 2020 (pre-pandemic), the surgical resectability rate was 20%. The subsequent 6 months (early pandemic), the resectability rate decreased to 11%. Afterward from October 2020 to June 2021 (late pandemic), the resectability rate increased to 27%. The resectability rate early pandemic was significantly lower than that for pre-pandemic and later pandemic combined (11% lower; 95% confidence interval [CI], 2%-20%). There was no significant difference in resectability rates pre-pandemic and later pandemic (7% difference; 95% CI, -3% to 16%). In subgroup analyses, the early pandemic was associated with a larger impact in BTC resectability rates than HCC resectability rates. Time from BTC symptom onset until Multidisciplinary Liver Clinic evaluation increased by over 6 weeks early pandemic versus pre-pandemic (Hazard Ratio, 0.63; 95% CI, 0.44-0.91).

Conclusions

During the early COVID-19 pandemic, we observed a drop in the percentage of patients presenting with curable liver cancers. This may reflect delays in liver cancer diagnosis and contribute to excess mortality related to the COVID-19 pandemic.

Intraarterial Therapies for the Management of Hepatocellular Carcinoma

Image-guided locoregional therapies play a crucial role in the management of patients with hepatocellular carcinoma (HCC). Transarterial therapies consist of a group of catheter-based treatments where embolic agents are delivered directly into the tumor via their supplying arteries. Some of the transarterial therapies available include bland embolization (TAE), transarterial chemoembolization (TACE), drug-eluting beads-transarterial chemoembolization (DEB-TACE), selective internal radioembolization therapy (SIRT), and hepatic artery infusion (HAI). This article provides a review of pre-procedural, intra-procedural, and post-procedural aspects of each therapy, along with a review of the literature. Newer embolotherapy options and future directions are also briefly discussed.

Adequacy of samples obtained via percutaneous core-needle rebiopsy for EGFR T790M molecular analysis in patients with non-small cell lung cancer following acquired resistance to first-line therapy: A systematic review and meta-analysis

MICRO ABSTRACT

Rebiopsies characterizing resistance mutations in patients with non-small cell lung cancer (NSCLC) can guide personalized medicine and improve overall survival rates. In this systematic review, we examine the suitability of percutaneous core-needle biopsy (PT-CNB) to obtain adequate samples for molecular characterization of the acquired resistance mutation T790M. This review provides evidence that PT-CNB can obtain samples with high adequacy, with a mutation detection rate that is in accordance with prior literature.

BACKGROUND

Non-small cell lung cancer (NSCLC) comprises 85% of all lung cancers and has seen improved survival rates with the rise of personalized medicine. Resistance mutations to first-line therapies, such as T790M, however, render first-line therapies ineffective. Rebiopsies characterizing resistance mutations inform therapeutic decisions, which result in prolonged survival. Given the high efficacy of percutaneous core-needle biopsy (PT-CNB), we conducted the first systematic review to analyze the ability of PT-CNB to obtain samples of high adequacy in order to characterize the acquired resistance mutation T790M in patients with NSCLC.

METHODS

We performed a comprehensive literature search across PubMed, Embase, and CENTRAL. Search terms related to "NSCLC," "rebiopsy," and "PT-CNB" were used to obtain results. We included all prospective and retrospective studies that satisfied our inclusion and exclusion criteria. A random effects model was utilized to pool adequacy and detection rates of the chosen articles. We performed a systematic review, meta-analysis, and meta-regression to investigate the adequacy and T790M detection rates of samples obtained via PT-CNB.

RESULTS

Out of the 173 studies initially identified, 5 studies met the inclusion and exclusion criteria and were chosen for our final cohort of 436 patients for meta-analysis. The pooled adequacy rate of samples obtained via PT-CNB was 86.92% (95% CI: [79.31%, 92.0%]) and the pooled T790M detection rate was 46.0% (95% CI: [26.6%, 66.7%]). There was considerable heterogeneity among studies (I² > 50%) in both adequacy and T790M detection rates.

CONCLUSION

PT-CNB can obtain adequate samples for T790M molecular characterization in NSCLC lung cancer patients. Additional prospective studies are needed to corroborate the results in this review.

Development, Practice Patterns, and Early Clinical Outcomes of a Multidisciplinary Liver Cancer Clinic

Multidisciplinary care has been associated with improved survival in patients with primary liver cancers. We report the practice patterns and real world clinical outcomes for patients presenting to the Johns Hopkins Hospital (JHH) multidisciplinary liver clinic (MDLC). We analyzed hepatocellular carcinoma (HCC, n = 100) and biliary tract cancer (BTC, n = 76) patients evaluated at the JHH MDLC in 2019. We describe the conduct of the clinic, consensus decisions for patient management based on stage categories, and describe treatment approaches and outcomes based on these categories. We describe subclassification of BCLC stage C into 2 parts, and subclassification of cholangiocarcinoma into 4 stages. A treatment consensus was finalized on the day of MDLC for the majority of patients (89% in HCC, 87% in BTC), with high adherence to MDLC recommendations (91% in HCC, 100% in BTC). Among patients presenting for a second opinion regarding management, 28% of HCC and 31% of BTC patients were given new therapeutic recommendations. For HCC patients, at a median follow up of 11.7 months (0.7-19.4 months), median OS was not reached in BCLC A and B patients. In BTC patients, at a median follow up of 14.2 months (0.9-21.1 months) the median OS was not reached in patients with resectable or borderline resectable disease, and was 11.9 months in patients with unresectable or metastatic disease. Coordinated expert multidisciplinary care is feasible for primary liver cancers with high adherence to recommendations and a change in treatment for a sizeable minority of patients.

Characteristics and Outcomes of Percutaneous Biliary Interventions in the United States

OBJECTIVE

To explore baseline characteristics, comorbidities, and clinical diagnoses in the prediction of outcomes for inpatient percutaneous biliary interventions in the United States.

METHODS

Hospitalizations for percutaneous transhepatic cholangiography and percutaneous biliary drainage were studied using the National Inpatient Sample 2012 to 2015. Associations between baseline characteristics, comorbidities, clinical diagnoses, and outcomes were analyzed using multivariable regression modeling. Regional variations were studied in an exploratory analysis.

RESULTS

Hospitalizations for percutaneous biliary interventions had average inpatient mortality of 3.8% ± 0.8% and length of stay of 7.6 ± 0.3 days. Hypertension was the most common comorbidity (50.5% ± 0.8%), and paralysis was associated with the highest inpatient mortality (19.1% ± 5.7%) and length of stay (11.4 ± 1.3 days). Compared with nonmalignant biliary-pancreatic disorders, sepsis was associated with the highest inpatient mortality (6.5% ± 1.1%; adjusted odds ratio [aOR]: 5.2 [3.9-7.0]) and length of stay (9.0 ± 3.0 days; aOR: 2.2 [1.9-2.5]), followed by underlying malignancy (mortality of 5.5% ± 0.6%; aOR: 2.3 [1.7-3.0]; length of stay of 8.3 ± 0.2 days; aOR: 1.6 [1.4-1.8]). The observed associations were independent of baseline characteristics and comorbidities. With regard to regional variations, the Middle Atlantic states had the lengthiest hospital stays (38.8% ± 2.0% >8 days) and the East South Central states had the highest inpatient mortality (6.6% ± 1.6%) while having the highest frequency of malignancy (37.9% ± 3.7%) and the lowest frequency of postoperative cases (15.2% ± 2.4%).

CONCLUSION

In addition to baseline characteristics and comorbidities, sepsis and malignancy were determinants of higher mortality and increased length of stay in hospitalizations for percutaneous biliary interventions. We observed significant regional variations in clinical diagnoses and outcomes across the United States.

Minimally invasive treatment of abdominal lymphocele: A review of contemporary options and how to approach them

Lymphoceles are lymphatic fluid collections resulting from lymphatic vessel disruption after surgery or trauma. They are most often described following retroperitoneal surgeries such as cystectomies, prostatectomies, renal transplants, and gynecologic surgeries. Most lymphoceles are asymptomatic and resolve spontaneously without treatment. If persistent, they can become infected or exert mass effect on adjacent structures causing pain, urinary, or lower limb edema particularly for lymphoceles in the pelvis Symptomatic lymphoceles should be treated to relieve symptoms and prevent functional compromise of vital adjacent structures. Although surgery has been traditionally accepted as the gold standard treatment, advances in imaging and interventional technology allow for less invasive, percutaneous treatment. Available minimally invasive treatment options include percutaneous aspiration, catheter drainage, sclerotherapy, and lymphangiography with lymphatic embolization. A review of these treatment options and a suggested algorithm for managing lymphoceles is presented.

Pressure-Enabled Drug Delivery Approach in the Pancreas with Retrograde Venous Infusion of Lipiodol with Ex Vivo Analysis

Purpose

To determine the safety and feasibility of pancreatic retrograde venous infusion (PRVI) utilizing a microvalvular infusion system (MVI) to deliver ethiodized oil (lipiodol) by means of the Pressure-Enabled Drug Delivery (PEDD) approach.

Methods

Utilizing transhepatic access, mapping of the pancreatic body and head venous anatomy was performed in 10 swine. PEDD was performed by cannulation of veins in the head (n = 4) and body (n = 10) of the pancreas with a MVI (Surefire® Infusion System (SIS), Surefire Medical, Inc (DBA TriSalus™ Life Sciences)) followed by infusion with lipiodol. Sets of animals were killed either immediately (n = 8) or at 4 days post-PRVI (n = 2). All pancreata were harvested and studied with micro-CT and histology. We also performed three-dimensional volumetric/multiplanar imaging to assess the vascular distribution of lipiodol within the glands.

Results

A total of 14 pancreatic veins were successfully infused with an average of 1.7 (0.5–2.0) mL of lipiodol. No notable change in serum chemistries was seen at 4 days. The signal-to-noise ratio (SNR) of lipiodol deposition was statistically increased both within the organ in target relative to non-target pancreatic tissue and compared to extra pancreatic tissue (p < 0.05). Histological evaluation demonstrated no evidence of pancreatic edema or ischemia.

Conclusions

PEDD using the RVI approach for targeted pancreatic infusions is technically feasible and did not result in organ damage in this pilot animal study.

Endovascular Model of Rabbit Hindlimb Ischemia: A Platform to Evaluate Therapeutic Angiogenesis

PURPOSE

Current animal hindlimb ischemia models involve surgical ligation of the femoral artery and delivery of therapeutic angiogenic agents into the adductor compartment. The authors hypothesize that an endovascular model of hindlimb ischemia would be a more appropriate platform, closely resembling atherosclerosis by occluding the vessel from within, causing less inflammation, wound healing and subsequent collateralization.

MATERIALS AND METHODS

The left superficial femoral artery in 17 rabbits was occluded by endovascular coil embolization (n=9) or surgical ligation (n=8). Animals (n=3; in each group) were sacrificed on day 3 to determine the arteriolar luminal area, number of arterioles, microsphere determined perfusion, and degree of inflammation. On day 28, the remaining animals underwent calf blood pressure measurements and angiography to determine the number of collaterals and diameter of vessels supplying the hindlimb.

RESULTS

Immediate postprocedure (day 0) and presacrifice (day 3 or 28) occlusion rates were 89% (eight of nine rabbits) and 100% for the endovascular model; 100% and 100% for the surgical model, respectively. Hindlimb paralysis and muscle atrophy was found in one surgical animal. On day 3, there was an increase in hindlimb perfusion (surgery, 0.04+/-0.01; endovascular, 0.02+/-0.01; P=.02), an increase in arteriolar luminal area (surgery, 481 microm+/-240; endovascular, 345 microm+/-151; P=.04), and a trend toward more inflammation (surgery, 5.5+/-3.8; endovascular, 2.5+/-3.0; P=.08) in the surgical group. There was no difference in number of vessels between both groups. On day 28 there was no difference in the calf blood pressure ratios or in the number of collaterals. However, there was enlargement of the distal profunda femoris artery, the vessel closest to the surgical incision, in the surgical group (L/R ratio: immediate post-occlusion, 1.06+/-0.11; day 28, 1.27+/-0.08; P=.02).

CONCLUSION

The endovascular model was efficacious in providing occlusion of the superficial femoral artery, and induced less of an arteriogenic response compared with the surgical model. The authors believe that this endovascular model is a superior platform for studying therapeutic angiogenic agents.

Human peripheral arteries: feasibility of transvenous intravascular MR imaging of the arterial wall

Feasibility of in vivo transvenous intravascular magnetic resonance (MR) imaging of the human arterial wall was determined. All subjects provided written informed consent, and institutional review board approved the study. Six arteries in six patients were imaged with a guidewire placed in the iliac vein (n = 5) or left renal vein (n = 1). Pre- and postcontrast T1-weighted and T2-weighted transvenous MR imaging were performed. An atherosclerotic plaque with a fibrous cap was identified on 27 (42%) of 64 images of veins without stents; intimal hyperplasia in a renal artery with a stent was identified on 12 images. Contrast-to-noise ratios (CNRs) on arterial wall postcontrast T1-weighted images were superior to those on images obtained with other sequences (P < .001), and the postcontrast images demonstrated the greatest number of plaques with a low-signal intensity core and fibrous cap. Preliminary results show that transvenous MR imaging is feasible for high-spatial-resolution imaging of the arterial wall and atherosclerotic plaque. Postcontrast T1-weighted imaging affords greatest CNR for the arterial wall.

Therapeutic angiogenesis: the next frontier for interventional radiology

The field of interventional radiology has traditionally relied on mechanical methods to treat vascular disease, such as angioplasty balloons and stents. Although there have been a number of important technical advances in endovascular devices, there are still a number of patients who are not candidates for percutaneous or surgical revascularization. As we approach the technical limits of these newer devices, therapeutic angiogenesis may play an ever-increasing role in the future. Interventional radiologists have unique delivery skills that would complement the on-going research in this area. It is the goal of this article to serve as a primer for interventional radiologists on the agents and techniques used in this exciting field.

In Vivo Intravascular MR Imaging: Transvenous Technique for Arterial Wall Imaging

PURPOSE

To determine, in vivo, the potential for transvenous magnetic resonance (MR) imaging of the arterial wall and to assess appropriate MR pulse sequences for this method.

MATERIALS AND METHODS

MR imaging was performed on 19 vessels (right renal artery, N = 9; left renal artery N = 2; external iliac artery, N = 4; abdominal aorta, N = 4) in nine swine. The animals were either low-density lipoprotein receptor knockout (N = 5) or Yucatan mini-pigs fed an atherogenic diet for 6 to 11 weeks (N = 4). The intravascular MR coil/guide wire (IVMRG) (Surgi-Vision, Gaithersburg, MD) was introduced via the external iliac vein into the inferior vena cava (IVC). The following electrocardiograph-gated MR pulse sequences were obtained: T1-weighted precontrast with and without fat saturation and T1-weighted postcontrast with fat saturation. Two observers scored wall signal and conspicuity and classified the vessel as normal, abnormal, or stented. Images were compared with histopathologic findings.

RESULTS

The T1-weighted precontrast without fat saturation, T1-weighted precontrast with fat saturation, and T1-weighted postcontrast images correlated with histopathologic findings in 12 of 15 vessels, eight of 10 vessels, and 14 of 16 vessels, respectively. Abnormal histopathologic findings included: arterial wall thickening (N = 3), arterial dissection (N = 2), focal fibrous plaque (N = 2), adherent thrombus (N = 1). The T1-weighted postcontrast images were not compromised by artifacts and had the highest score for vessel wall signal and conspicuity. T1-weighted precontrast images were compromised by chemical shift artifact and poor blood suppression. Negligible artifacts were created by the platinum stent.

CONCLUSION

The T1-weighted fat saturated postcontrast pulse sequence was superior to other sequences for transvenous MR imaging of the arterial wall.

Transcatheter coil embolization of large pulmonary artery pseudoaneurysms in a child

The authors report a case of a 5-year-old boy who initially presented with mastoiditis, underwent successful surgical treatment, and during the immediate postoperative period developed multiple, bilateral pulmonary artery pseudoaneurysms. The large size and multiplicity of the pseudoaneurysms precluded the patient from undergoing thoracic surgery. Successful endovascular coil and wire embolization was performed in a staged set of procedures with use of more than 30 m of wire and coils.

Arteriographic and pathologic evaluation of two suture-mediated arterial closure devices in a porcine model

PURPOSE

To determine the acute and short-term effects the Sutura 8-F SuperStitch and Perclose 6-F Closer devices have on the femoral artery, as determined by angiography and pathologic examination.

MATERIALS AND METHODS

From a common carotid artery cutdown, eight pigs underwent pelvic angiography (i) before placement of bilateral common femoral artery vascular sheaths, (ii) after sheath insertion, and (iii) after device deployment. Two pigs were immediately killed; six survived 4 weeks for repeat angiography and vessel harvest.

RESULTS

Average vessel diameter before sheath insertion was 5.9 mm +/- 0.6 and 5.8 mm +/- 0.6 for vessels with Perclose and Sutura devices, respectively. After deployment of the Sutura device, there was a 44.7% (P =.001) mean diameter reduction from preprocedural diameters, compared to a 59.3% reduction (P <.001) with the Perclose device. After deployment of the Sutura device, there was a mean vessel diameter reduction of 14.1% (P =.53) versus the diameter immediately after sheath placement. After deployment of the Perclose device, there was a mean vessel diameter reduction of 43.8% (P =.05) versus the diameter immediately after sheath placement. At 4-week angiography, all vessels returned to their original diameters before sheath insertion. Pathologic examination showed mild adventitial fibrosis creating a "fibrous hood" surrounding the suture and vessel.

CONCLUSIONS

Despite significant luminal compromise after device deployment, all vessels appeared normal on angiography at 4 weeks. Contrary to the normal angiographic findings, both devices incited periadventitial fibrosis, which created a fibrous hood around the suture and vessel.

Diagnostic accuracy of magnetic resonance cholangiopancreatography and ultrasound compared with direct cholangiography in the detection of choledocholithiasis

AIM

To determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and trans-abdominal ultrasound in the detection of choledocholithiasis, and to compare bile duct stone characteristics using endoscopic retrograde cholangiopancreatography (ERCP), MRCP and ultrasound.

MATERIALS AND METHODS

Of 191 consecutive patients referred for diagnostic ERCP, choledocholithiasis was diagnosed in 34 patients using direct cholangiography. The latter took the form of ERCP (n = 29), intraoperative cholangiography (n = 3) or percutaneous transhepatic cholangiography (n = 2). All patients underwent MRCP and ultrasound examinations and their findings for choledocholitiasis were compared with those at direct cholangiography. Finally, in the 29 patients with choledocholithiasis diagnosed under ERCP, stone characteristics were compared across the three investigations of ERCP, MRCP and ultrasound.

RESULTS

Compared with direct cholangiography, MRCP showed a sensitivity, specificity and diagnostic accuracy of 91%, 98% and 97%, respectively, in the diagnosis of choledocholithiasis. MRCP resulted in three false-negative and three false-positive findings, four of which occurred due to confusion with lesions at the ampulla. Ultrasound showed a sensitivity, specificity and diagnostic accuracy of 38%, 100% and 89%, respectively, in the diagnosis of choledocholithiasis. ERCP revealed a greater number of stones and these were more proximally distributed within the bile ducts when compared to MRCP.

CONCLUSIONS

MRCP is highly accurate in the diagnosis of choloedocholithiasis and has the potential to replace diagnostic ERCP. MRCP underestimates the number of bile duct stones present.

The diagnostic accuracy of magnetic resonance cholangiopancreatography and ultrasound compared with direct cholangiography in the detection of choledocholithiasis

AIM

To determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and ultrasound (US) in the diagnosis of choledocholithiasis in a large group of patients with bile duct stones confirmed at direct cholangiography. Also, to compare bile duct stones confirmed at direct cholangiography. Also, to compare bile duct stone characteristics using the three different investigations, endoscopic retrograde cholangiopancreatography (ERCP), MRCP and US.

MATERIALS AND METHODS

191 patients (M:F, 76:115; mean age, 66 years; range, 24-92 years) were investigated by direct cholangiography, MRCP and US. Their final diagnosis as determined at direct cholangiography were choledocholithiasis (n = 34), strictures (n = 47) and normal ducts (n = 110). The direct cholangiographic methods used for diagnosis of choledocholithiasis were ERCP (n = 29), intraoperative cholangiography (n = 3) and percutaneous transhepatic cholangiography (n = 2). The bile duct stone characteristics were compared using ERCP, MRCP and US in the 29 patients in whom stones were exclusively diagnosed by ERCP.

RESULTS

Compared with the final diagnosis, MRCP had a sensitivity, specificity and diagnostic accuracy of 91%, 98% and 97%, respectively, in the diagnosis of choledocholithiasis. MRCP resulted in three false-negative and three false-positive findings, four of which occurred due to confusion with lesions at the ampulla. US had a sensitivity, specificity and diagnostic accuracy of 38%, 100% and 89%, respectively, in the diagnosis of choledocholithiasis. ERCP diagnosed more stones and the stones were more proximally distributed within the bile duct at ERCP when compared with MRCP.

CONCLUSION

MRCP has a high diagnostic accuracy (97%), similar to that at direct cholangiography, in the diagnosis of choloedocholithiasis. It has the potential to replace diagnostic ERCP and select patients with choledocholithiasis for therapeutic ERCP.

Recurrent TIPS failure associated with biliary fistulae: treatment with PTFE-covered stents

PURPOSE

To evaluate the efficacy of covered stents for the treatment of transjugular intrahepatic portosystemic shunt (TIPS) obstruction in human subjects with identified or suspected biliary fistulae.

METHODS

Five patients were treated for early failure of TIPS revisions. All had mid-shunt thrombus, and four of these had demonstrable biliary fistulae. Three patients also propagated thrombus into the native portal venous system and required thrombolysis. TIPS were revised in four patients using a custom-made polytetrafluoroethylene (PTFE)-covered Wallstent, and in one patient using a custom-made PTFE-covered Gianturco Z-stent.

RESULTS

All identified biliary fistulae were successfully sealed. All five patients maintained patency and function of the TIPS during follow-up ranging from 2 days to 21 months (mean 8.4 months). No patient has required additional revision. Thrombosis of the native portal venous system was treated with partial success by mechanical thrombolysis.

CONCLUSION

Early and recurrent failure of TIPS with mid-shunt thrombosis, which may be associated with biliary fistulae, can be successfully treated using covered stents. Stent-graft revision appears to be safe, effective, and potentially durable.

Percutaneous endoluminal placement of stent-grafts for the treatment of isolated iliac artery aneurysms

PURPOSE

To evaluate the feasibility of stent-grafts for treatment of isolated iliac artery aneurysms (IAAs).

MATERIALS AND METHODS

Nine IAAs in eight patients were treated with transluminally placed endovascular stent-grafts. All patients were men (median age, 72 years). In three, the aneurysm involved both the common and internal iliac arteries. In one, common and external iliac arteries were involved. The other aneurysms involved only the common iliac artery. Two aneurysms were treated with balloon-expandable stents covered with polytetrafluoroethylene (PTFE) graft material, three were treated with self-expanding Z-stents covered with a woven polyester graft, and four were treated with self-expanding Z-stents covered with PTFE.

RESULTS

Transluminal placement of the stents was successful in all patients with thrombosis of the aneurysms. There were no distal thromboembolic events, deaths, or infections. The median follow-up period was 8.5 months.

CONCLUSION

Initial results suggest that transluminal stent-graft placement for treating isolated IAAs is a safe and effective alternative to surgery in selected patients. Long-term follow-up data are needed before this approach can be recommended for the primary treatment of IAAs.

Endovascular stent-grafting after arch aneurysm repair using the "elephant trunk"

A 68-year-old woman with severe chronic obstructive pulmonary disease, aortic valvular insufficiency, and diffuse thoracic aortic aneurysm underwent aortic valve replacement and separate Dacron graft replacement of the ascending aortic and arch aneurysms using the elephant trunk technique. She was discharged on the tenth postoperative day. Five months later, she underwent endovascular stent-graft repair of the descending thoracic aortic aneurysm. She recovered uneventfully, and was discharged on the third postoperative day. Follow-up computed tomography at 6 months demonstrated exclusion of all flow into the descending thoracic aortic aneurysm. The elephant trunk technique followed by endovascular stent-grafting of the descending thoracic component is a potential therapeutic option in selected high-risk patients with diffuse aortic aneurysmal disease.

Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneurysms

BACKGROUND

The usual treatment for thoracic aortic aneurysms is surgical replacement with a prosthetic graft, but the associated morbidity and mortality are considerable. We studied the use of transluminally placed endovascular stent-graft devices as an alternative to surgical repair.

METHODS

We evaluated the feasibility, safety, and effectiveness of transluminally placed stent-graft to treat descending thoracic aortic aneurysms in 13 patients over a 24-month period. Atherosclerotic, anastomotic, and post-traumatic true or false aneurysms and aortic dissections were treated. The mean diameter of the aneurysms was 6.1 cm (range, 5 to 8). The endovascular stent-grafts were custom-designed for each patient and were constructed of self-expanding stainless-steel stents covered with woven Dacron grafts.

RESULTS

Endovascular placement of the stent-graft prosthesis was successful in all patients. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent-graft in 12 patients, and partial thrombosis in 1. Two patients initially had small, residual patent proximal tracts into the aneurysm sac, but both tracts thrombosed within two months after the procedure. In four patients, two prostheses were required to bridge the aneurysm adequately. There have been no deaths or instances of paraplegia, stroke, distal embolization, or infection during an average follow-up of 11.6 months. One patient with an extensive chronic aortic dissection required open surgical graft replacement four months later because of progressive dilatation of the arch.

CONCLUSIONS

These preliminary results demonstrate that endovascular stent-graft repair is safe in highly selected patients with descending thoracic aortic aneurysms. This new method of treatment will, however, require careful long-term evaluation.

A mechanically detachable coil for the treatment of aneurysms and occlusion of blood vessels

PURPOSE

To evaluate mechanically detachable coil designs capable of controlled and instantaneous release within an aneurysm or vascular space.

METHODS

Three mechanically detachable coil designs, clamped ball, looped ribbon, and interlocking cylinder, were evaluated using in vitro and in vivo testing to study reliability of coil release, retractability, and coil behavior in a microcatheters. In vitro tests were performed using a glass side-wall aneurysm model and conventional microcatheters. In vivo experiments in rabbits included aneurysm models (side-wall and bifurcation) and arterial occlusions (carotid and renal).

RESULTS

All three designs deployed coils easily and were able to retract coils after partial deployment. Motion was seen in previously released coils and in the catheter when using the clamped ball and looped ribbon designs. The interlocking cylinder design did not cause similar motion. When compared with the other two designs, the interlocking cylinder had significantly greater separation forces between coil pusher and coil while in the catheter. Frictional forces within the catheter were lower for the interlocking cylinder mechanically detachable coil design than for a commercially available conventional coil and coil pusher system. During in vivo testing, the mechanically detachable coil design operated smoothly in the catheter, providing good release and retraction in aneurysms and straight vessels.

CONCLUSION

The interlocking cylinder mechanically detachable coil design is superior to the other two tested designs. The mechanically detachable coil was reliably delivered and detached in in vivo testing for the treatment of aneurysms and for the occlusion of blood vessels.