Covered Stent Placement Research Articles

Effectiveness and outcome of endovascular therapy for late-onset postpancreatectomy hemorrhage using covered stents and embolization

The purpose of this study was to evaluate the clinical and long-term outcome of patients who underwent covered stent treatment because of late-onset postpancreatectomy hemorrhage in a greater number of patients. A secondary study goal was to compare embolization techniques with covered stents regarding differences in early and late clinical outcome, rebleeding, and vessel patency. Between December 2008 and June 2015, 27 consecutive patients suffering from major hemorrhage after pancreatic surgery underwent either covered stent placement or embolization of the affected visceral artery. The patients' medical reports and radiologic images were retrospectively reviewed. The main study end point was technical and clinical success, including survival and complications; the secondary end points were perfusion distal to the target vessel and, for covered stent placement, patency of the affected artery. Covered stent placement was successful in 14 of 16 patients (88%); embolization was successful in 10 of 11 (91%) patients. For the embolization group, the overall 30-day and 1-year survival rate was 70%, and the 1- and 2-year survival rate was 56%; for the covered stent group, these rates were 81% and 74%, respectively. The 30-day patency of the covered stent was 84%, and 1-year patency was 42%; clinically relevant ischemia was observed in two patients. Infarction distal to the embolized vessel occurred in 6 of 11 patients (55%). Endovascular treatment using either covered stents or embolization techniques is an effective and safe emergency therapy for life-threatening postpancreatectomy hemorrhage with good clinical success rates and long-term results. Covered stent placement preserving vessel patency in the early postoperative phase should be preferred to embolization if it is technically feasible.

Preoperative Protective Endovascular Covered Stent Placement Followed by Surgery for Management of the Cervical Common and Internal Carotid Arteries with Tumor Encasement.

Objective The objective of this study was to report the outcomes on a preliminary cohort of patients with tumor encasement of either, or both, the cervical internal carotid artery (ICA) and common carotid artery (CCA) following preoperative covered stent placement and surgical resection. Setting This study was set at the University of Florida College of Medicine, Jacksonville, FL. Participants Subjects who received preoperative stenting of the cervical ICA/CCA before surgical resection of head and neck tumors between April 1, 2015, and July 31, 2015 were participated. Main Outcome Measures The outcomes assessed were resectability of tumors after stenting, histopathological assessment of specimen margins, complications associated with stenting. Results Five subjects received preoperative covered stent placement of the ICA/CCA before surgical resection. The mean age was 65.2 years. Median follow-up was 3.5 months. Excision of the adventitia from the stent was performed in all subjects. No intraoperative complications occurred. One vascular-related complication occurred in one subject who suffered occlusion of the stent, sustaining a ministroke. No involvement of tumor at the deep margin (inner surface of adventitia) of the resection was seen in any subjects. Conclusions Preoperative covered stent placement of the cervical ICA/CCA in the management of subjects with head and neck tumors who display encasement on preoperative imaging may represent a safe and effective treatment.

Safety and Efficacy of Percutaneous Biliary Covered Stent Placement in Patients with Malignant Biliary Hilar Obstruction; Correlation with Liver Function.

To estimate the safety and efficacy of percutaneous ePTFE-covered biliary stent placement and the relationship between underlying liver function and stent patency in patients with malignant hilar obstruction. From March 2012 to June 2015, 41 patients [22 females, 19 males; mean age 69.8 (range 34-94) years] with malignant biliary obstruction underwent percutaneous biliary stent placement (31 patients with unilateral, 10 patients with bilateral side-by-side). Cumulative patient survival and stent patency rate curves were derived using the Kaplan-Meier method. A Cox model was used to explore the relationship between liver function and patient survival, and also biliary stent patency. Pearson correlation coefficient was used to analyze the relationship between patient survival and stent patency. Technical success rate was 100% and clinical success rate was 95%. During follow-up, four complications occurred (two bilomas and two cases of acute cholecystitis) and were treated successfully with percutaneous drainage. No other complication occurred. Mean serum bilirubin level was 11.34±7.35mg/dL before drainage and 5.00±4.83mg/dL 2 weeks after stent placement. The median patent survival duration was 147days (95% CI, 69.6-224.4days). The median stent patency duration was 101days (95% CI, 70.0-132.0days). The cumulative stent patency rates at 1, 3, 6, and 12months were 97, 57.6, 30.3, and 17.0%, respectively. Child-Pugh score was correlated significantly with patient survival (P=0.011) and stent patency (P=0.007). MELD score was correlated significantly with stent patency (P=0.044). There was a correlation between patient survival and stent patency (r=0.778, P<0.001). Percutaneous placement of ePTFE-covered biliary stent was a safe and an effective method for malignant biliary obstruction. Underlying liver function seemed to be one of the important factors affecting patient survival and stent patency, and stent patency showed statistically significant correlation with patient survival.

Outcomes of Temporary Partially Covered Stent Placement for Benign Tracheobronchial Stenosis.

To evaluate the intermediate outcomes of temporary partially covered tracheobronchial stenting in patients with benign tracheobronchial stenosis. We conducted a retrospective study of patients with benign tracheobronchial stenosis who underwent stent placement. All stents were removed approximately 3months after placement. Respiratory function was assessed using the visual analogue scale (VAS) and Karnofsky performance status scale (KPS) before and after stent placement. The lumen diameters of the stenotic lesions were measured using chest computed tomography (CT) and compared between before stent placement and after stent removal. A total of 51 stents were successfully placed in consecutive 51 patients with benign tracheobronchial stenosis. No serious complications occurred. The mean VAS and KPS scores significantly improved after stent removal (6.291±0.495 and 25.352±10.533, respectively) compared with those before stent placement (1.493±0.504 and 60.140±16.344, respectively; P<0.05). The mean lumen transverse diameters of the stenotic site in trachea and main bronchus after stent removal (17.235±3.457 and 8.993±0.961mm; 1month post-removal; 16.353±4.132 and 8.357±1.082mm; 6months post-removal) were significantly larger than those before stent placement (7.876±2.351 and 2.143±0.770mm, respectively; P<0.05). However, the mean lumen diameters between 1 and 6months after stent removal had no significant difference (P>0.05). Temporary partially covered stenting may be a safe and effective treatment for benign tracheobronchial stenosis.

Delayed Severe Hemobilia Due to Bilio-venous Fistula After Percutaneous Transhepatic Biliary Drainage: Treatment With Covered Stent Placement

Biliovenous fistula occurs due to development of a communication between hepatic duct and portal vein branches and is a rare complication of percutaneous transhepatic biliary drainage (PTBD). Most of them are self-limiting and only occasionally they need interventional management. Placement of biliary stent graft is a viable option. We present here a case of a 56-year-old male with carcinoma of gall bladder presenting with hemodynamic shock due to severe hemobilia after PTBD and treated successfully by biliary covered stent placement.

Uncertain Patency of Covered Stents Placed for Traumatic Axillosubclavian Artery Injury

Traumatic axillosubclavian artery injuries (ASAIs) are uncommon but devastating. There is increasing acceptance of covered stent use for ASAIs. However, epidemiologic and long-term outcomes data are limited. We investigated national trends in ASAI management and our institutional outcomes after emergent covered stent placement and open surgical repairs for ASAIs. A review of the National Trauma Data Bank from 2010 to 2012 was performed for epidemiologic data. International Classification of Diseases and procedure codes were used to identify ASAIs and therapy type. A single-center, retrospective review of consecutive patients with ASAIs between January 2010 and August 2014 was also performed. National Trauma Data Bank review included 511,286 patients with 520 ASAIs, yielding an incidence of 0.1%. Endovascular therapy was used in 76 patients (14.7%) vs open repair in 280 patients (53.8%). Nonoperative or unknown treatment was used in 164 (31.5%). From 2010 to 2012, endovascular interventions increased from 11.3% to 17.2% (p < 0.05). Endovascular therapy was used more frequently in blunt compared with penetrating trauma (59.2% vs 40.8%; p < 0.005). Our institutional review identified 10 ASAIs treated with covered stents with a median follow-up of 117 days (interquartile range 13 to 447 days) and 70% lost to follow-up. No treatment-related mortality or amputation occurred. Stent occlusion occurred in 30% at a median of 132 days (interquartile range 30 to 223 days). Three patients with ASAIs were initially treated with open surgery, 2 died and the third required ligation. Covered stents are being used increasingly for ASAIs nationwide, despite variable reports of durability. Follow-up is poor in urban trauma centers and might be responsible for the variable patency. Population-based efforts to improve compliance among trauma patients can help improve covered stent patency in ASAI.

Renal duplex ultrasound findings in fenestrated endovascular aortic repair for juxtarenal aortic aneurysms

This study characterized duplex ultrasound (DUS) findings and clinical outcomes associated with covered stent placement in renal arteries during fenestrated endovascular aortic repair (FEVAR) to determine if velocity criteria for native renal artery stenosis can be applied. Data from a prospectively maintained database of patients who underwent FEVAR between January 2010 and August 2014 were obtained before FEVAR (preoperative or baseline) and at follow-up assessments at 30days, 6months, and 1, 2, and 3years. The established DUS threshold criteria for ≥60% stenosis in native renal arteries were applied at baseline and all follow-up intervals: renal artery peak systolic velocity (PSV) ≥200cm/s or renal-aortic velocity ratio (RAR) ≥3.5. Forty-nine patients underwent placement of 88 covered renal artery stents during FEVAR. At least 30-day follow-up was available for 43 patients with 80 stents. A ≥60% stenosis was identified in seven renal arteries of six patients on baseline DUS, and these patients were analyzed separately. The remaining 73 renal arteries were classified as normal or<60% stenosis at baseline, with a median PSV of 121cm/s (interquartile range, 96-143) and median RAR of 1.4 (interquartile range, 1.1-1.7). No significant differences were found between the baseline and follow-up PSV measurements at any time point. The RAR differed significantly at some time points, although median values remained below the ≥60% stenosis threshold. Some increased RAR values were attributed to low aortic velocities after repair. In the 13 patients with 17 covered renal artery stents found to have PSV or RAR exceeding a DUS threshold for ≥60% native renal artery stenosis, there was no evidence of stenosis by computed tomography angiography, of renal dysfunction by estimated glomerular filtration rate, or of renal volume decrease by three-dimensional analysis. None of the seven renal arteries with ≥60% stenosis atbaseline showed evidence of restenosis at 1, 2, or 3years. Covered stent placement in nonstenotic renal arteries during FEVAR is safe and durable, with PSV and RAR remaining in the normal or<60% stenosis range in most patients. Increases in PSV or RAR that occur are not associated with clinically significant sequelae or in-stent stenosis on computed tomography angiography. DUS velocity criteria for stenosis in native renal arteries appear to overestimate the severity of stenosis in covered stents after FEVAR.

Sharp Central Venous Recanalization in Hemodialysis Patients: A Single-Institution Experience

We report our institutional experience with sharp central venous recanalization in chronic hemodialysis patients who failed standard techniques. Since January 2014, a series of seven consecutive patients (four males and three females), mean age 35years (18-65years), underwent sharp central venous recanalization. Indications included obtaining hemodialysis access (n=6) and restoration of superior vena cava (SVC) patency to alleviate occlusion symptoms and restore fistula function (n=1). The transseptal needle was used for sharp recanalization in six patients, while it could not be introduced in one patient due to total occlusion of the inferior vena cava. Instead, transmediastinal SVC access using Chiba needle was obtained. Technical success was achieved in all cases. SVC recanalization achieved symptoms' relief and restored fistula function in the symptomatic patient. One patient underwent arteriovenous fistula creation on the recanalized side 3months after the procedure. The remaining catheters were functional at median follow-up time of 9months (1-14months). Two major complications occurred including a right hemothorax and a small hemopericardium, which were managed by covered stent placement across the perforated SVC. Sharp central venous recanalization using the transseptal needle is feasible technique in patients who failed standard recanalization procedures. The potential high risk of complications necessitates thorough awareness of anatomy and proper technical preparedness.

Follow-up for covered stent treatment of carotid blow-out syndrome in patients with head and neck cancer.

Carotid blow-out syndrome (CBS) is a life-threatening complication of head and neck cancer (HNC). One of the various methods used for emergency management of CBS is covered stent placement (CSP). Our initial experience in CSP is evaluated and compared with reports in the literature. This study analysed 17 patients with HNC who had received CSP for CBS at Kaohsiung Medical University Chung-Ho Memorial Hospital from May 2005 to December 2013. The medical records and images for these patients were retrospectively reviewed to evaluate the causes of CBS, treatment success rates and complications. The initial angiography success rate was 100%. Procedural or periprocedural complications were noted in two (12%) cases, both suffering from cerebral vascular accident (CVA). Short-term complications were noted in eight (47%) cases, including four rebleeding cases and four CVA cases. Medium- to long-term complications were noted in nine cases, which included two asymptomatic in-stent thrombosis cases, one symptomatic CVA case, two abscess formation cases and four rebleeding cases. Overall, eight (47%) cases of rebleeding occurred during follow-up. Three of the eight cases were fatal, accounting for 27% of the all-cause mortality. Although CSP is considered effective for achieving haemostasis in patients with HNC with CBS, the medium- to long-term outcomes are unfavourable owing to high risks of rebleeding, CVA and other complications. Therefore, CSP should be considered a temporary life-saving technique rather than a definitive treatment. Analysis of the relatively large series of patients with HNC in this study suggests that CSP is a useful temporary treatment for CBS.

Aortic Wall Injury Related to Endovascular Therapy for Aortic Coarctation.

Aortic wall complications can occur in unrepaired aortic coarctation (CoA) and after surgical repair or endovascular treatment. This review summarizes the available literature and current understanding of aortic wall injury (AWI) surrounding the management of CoA, focusing specifically on acute and follow-up AWI after endovascular treatment. There have been 23 reported cases of aortic rupture after endovascular treatment for CoA, including angioplasty alone, bare metal stenting, and primary covered stent therapy. Even if these published cases represent only a minority of ruptures that have actually occurred, the incidence is substantially <1%. The incidence of acute aneurysm formation was 0% to 13% after angioplasty, 0% to 5% after bare metal stent placement, and <1% after covered stent placement. The reported incidence and natural history of both acute and new AWI during follow-up after endovascular therapy for CoA varies considerably, likely secondary to ascertainment and reporting biases and inconsistent definitions. Although important AWI after endovascular treatment of CoA seems to be declining in frequency with increasing experience and improving technology, it remains one of the most important potential adverse outcomes. Long-term surveillance for new AWI and monitoring of existing AWI is mandatory, with institution of appropriate treatment when necessary. A central research focus in this population should be determination of the appropriate treatment for both native and recurrent CoA across various ages with regard to limiting recurrent CoA and preventing associated aortic wall complications, in addition to determining the appropriate treatment of various AWI. Consistent definitions and reporting are necessary to truly understand the incidence of, risk factors for, and measures protective against AWI after angioplasty or stent implantation for CoA.

A novel, ring-connected stent versus conventional GI stents: comparative study of physical properties and migration rates in a canine colon obstruction model

Migration of stents is one of the most common adverse events in covered stent placement in GI tract obstruction. To compare physical property and migration rates in a canine colon obstruction model among a novel stent and conventional stents. Comparative physical test and animal study. Medical device testing laboratory and animal laboratory. Mongrel dogs (N=26). Surgical colon obstruction followed by placement of a novel (n=13) or conventional (n=13) stent. Physical properties, migration, and adverse events. The novel stent showed better flexibility, as in a physical test of longitudinal compressibility and axial force, than did conventional stents, and it withstood the fatigue test for 10 days. In terms of radial force and tensile strength, the novel stent showed the same or better results than conventional stents. In a canine colon obstruction model, the migration rate of a novel stent was significantly lower than that of a conventional stent (2/13, 15.4% vs 8/13, 61.5%; P=.008). Animal study of limited size. The novel, ring-connected stent is more flexible and more resistant to migration than the conventional stents.

Section 11. Radiological intervention approaches to biliary complications after living donor liver transplantation.

Although endoscopic treatment has become the first choice to treat biliary complications, percutaneous transhepatic treatment still has important roles to treat biliary stricture or leak after living donor liver transplantation. This study reviewed a total of 527 recipients who had undergone percutaneous transhepatic treatment to treat biliary stricture (n=498) and leaks (n=29). Percutaneous transhepatic treatment included percutaneous transhepatic biliary drainage, perihepatic biloma drainage, balloon dilation of biliary stricture, and drainage catheter interposition or retrievable covered stent placement across a stricture or leak segment. Clinical success was achieved in 440 (88.4%) recipients with biliary stricture and 19 (65.5%) recipients with bile leaks. Percutaneous transhepatic treatment seems to be an effective alternative for treating biliary complications resistant to or inaccessible by endoscopic treatment.

Emergency reconstructive endovascular management of intraoperative complications involving the internal carotid artery from trans-sphenoidal surgery

PurposeTo report our experience with intraoperative complications involving the internal carotid artery (ICA) during trans-sphenoidal surgery and their outcome with reconstructive endovascular management.MethodsA retrospective review was conducted of patients with...

Covered Stent Placement for the Treatment of Malignant Superior Vena Cava Syndrome: Is Unilateral Covered Stenting Safe and Effective?

ObjectiveTo evaluate the safety and efficacy of unilateral covered stent placement in patients with malignant superior vena cava (SVC) syndrome.Materials and MethodsBetween October 2008 and November 2012, expanded polytetrafluoroethylene-covered stent placement for malignant SVC syndrome was performed in 40 consecutive patients (35 men and five women; mean age, 61.4 years; range, 35-81 years). All covered stents were unilaterally placed within the SVC or across the venous confluence when needed to relieve venous obstruction and prevent tumor overgrowth, regardless of patency of contralateral brachiocephalic veins.ResultsStent placement was technically successful in all patients. There were no major complications. Of the 37 patients symptomatic prior to stent placement, 34 (92%) experienced complete symptomatic relief 1-8 days after stent placement. Of the 29 patients who underwent covered stent placement across the venous confluence, nine patients had patent contralateral brachiocephalic veins prior to stent placement. However, no sign of SVC obstruction or contralateral upper extremity venous thrombosis was observed during the follow-up period. Kaplan-Meier analysis revealed median patient survival of 163 days. Stent occlusion occurred in four (10%) of 40 patents. Cumulative stent patency rates at 1, 3, 6, and 12 months were 95%, 92%, 86%, and 86%, respectively.ConclusionUnilateral covered stent placement appears to be a safe and effective method for treating malignant SVC syndrome, despite the location of SVC occlusion.

Successful endovascular treatment of iatrogenic thyrocervical trunk pseudoaneurysm with concomitant arteriovenous fistula using 0.010-inch detachable microcoils.

Pseudoaneurysms (PsA) and arteriovenous fistulae (AVF) of the thyrocervical trunk and its branches are rare complications of traumatic or iatrogenic arterial injuries. Most such injuries are iatrogenic and are associated with central venous catheterization. Historically, thyrocervical trunk PsA and AVF have been managed with open surgical repair; however, multiple treatment modalities are now available, including ultrasound-guided compression repair, ultrasound-guided thrombin injection, and endovascular repair with covered stent placement. We report a case of a 65-year-old woman with an iatrogenic thyrocervical trunk PsA with concomitant AVF that developed after attempted internal jugular vein cannulation for hemodialysis access. The PsA was successfully treated by transcatheter coil embolization using 0.010-inch detachable microcoils. Our case is the first published instance of a thyrocervical trunk PsA with concomitant AVF that was successfully treated by endovascular procedure.

Percutaneous Metallic Stent Placement in Patients with Cancer Recurrence at Bilioenterostomy Site

PurposeTo investigate the outcomes of percutaneous metallic stent placement in patients with malignant bilioenterostomy obstruction and to assess the risk factors influencing stent patency. Materials and MethodsFrom August 2008 to January 2012, 53 patients with malignant bilioenterostomy obstructions were treated with percutaneous placement of biliary metallic stents; this included expanded polytetrafluoroethylene (ePTFE)–covered stent placement in 36 patients and uncovered stent placement in 17 patients. ResultsA total of 75 stents were successfully placed in 53 patients. No major complications occurred in any patients, and minor complications occurred in nine patients (17%). The mean serum bilirubin level, which was 3.6 mg/dL ± 0.7 before drainage, decreased significantly to 2.5 mg/dL ± 0.4 at 1 month after stent placement (P = .041). Successful internal drainage was achieved in 44 of the 53 patients (83%). Kaplan–Meier analysis showed a median overall survival time of 145 days (95% confidence interval, 100–190 d), a median stent patency time of 313 days (95% confidence interval, 46–580 d), and cumulative stent patency rates at 1, 3, 6, 9, and 12 months of 91%, 75%, 64%, 56%, and 45%, respectively. Multivariate Cox regression analysis showed that the use of uncovered stents (odds ratio, 2.924; P = .033) was the only significant independent factor associated with stent occlusion. ConclusionsPercutaneous metallic stent placement is a safe and effective method for the treatment of patients with malignant bilioenterostomy obstruction. Moreover, as uncovered stent placement is the only significant independent factor associated with stent occlusion, ePTFE-covered stent placement is preferable in these patients.

1:54 PM Abstract No. 209 - Interventional treatment of thoracostomach-airway fistula after esophagogastrectomy with covered stents

Purpose To evaluate the clinical value of treating thoracostomach-airway fistula after esophagogastrectomy with covered stents. Materials and Methods Through SCT and digital radiography with water-soluble medium, We diagnosed 22 patients with thoracostomach-airway fistula (6 thoracostomach-tracheal fistulas, 2 thoracostomach-carina fistulas, 13thoracostomach-left principal bronchial fistulas, 1 thoracostomach-right principal bronchial fistula). Covered stents were selected on the base of the site, size and number of thoracostomach-airway fistula.Under the fluoroscopic guidance, 24 stents were implanted in the 22 patients with thoracostomach-airway fistulas. Results Stent placement was technically successful in all patients. The stent completely sealed off the fistula in 18 of 22 patients, choking after drinking and eating vanished as soon as the fistula was closed and a normal diet could be swallowed after the placement of the stents. 4 of 22 patients had persistent aspiration symptoms due to incomplete closure (initial clinical failure). During follow-up, the fistula reopened in 11 of 22 patients with initial clinical success. 8 reopened fistulas were sealed off with stent placement and 3 were inserted a feeding nasoenteric tube and a nasogastric decompression tube. All patients died during follow-up, and mean survival was 14±4.56 weeks (range, 1-42 weeks) after stent placement. Conclusion The airway covered stent placement is an effective and safe treatment for thoracostomach-airway fistula.

4:02 PM Abstract No. 107 - Outcomes of viabil covered stent placement for treatment of hepaticojejunostomy strictures

Purpose Viabil ePTFE/FEP-covered biliary stents have shown excellent patency and reported migration rates of 0.3% based on early clinical studies in patients with malignant biliary strictures. Strictures at surgical hepaticojejunostomy sites present a particular challenge because of the short landing zone within the duct. The purpose of this study is to assess outcomes of Viabil stent placement for hepaticojejunostomy strictures. Materials and Methods We retrospectively reviewed our records for Viabil stent placement procedures performed between Feb. 2006 and Sept. 2012 and included in this study patients who had undergone Viabil placement to treat hepaticojejunostomy strictures. The cause of stricture and follow-up clinical and radiographic data were collected. Results Of a total of 90 Viabil placement procedures in 88 patients, 13 patients underwent 14 interventions in which a Viabil stent was deployed across a hepaticojejunostomy for malignant (n=12) and benign (n=1) biliary strictures. The following sizes were used: 8×4 (n=5), 8×6 (n=6), 10×6 (n=4), 10×8 (n=1), and 10×10 (n=1) (mm diameter × cm length). One patient underwent stent placement in a double-barrel configuration, and another underwent stent placement in a Y configuration. During followup (mean 115 d, range 0-404 d), three stents (21% of placements), all 8x4 size, migrated: one on the day of placement and two detected 200 and 340 days later. There were no complications from stent passage. Three patients required reintervention for occluded 10 mm stents (21% of placements): One with benign stricture underwent stent removal (381 d), and two underwent biliary drain placement (137 and 155 d). One of the stent occlusion patients had Viabil stents placed in a Y configuration. Conclusion Viabil placement for hepaticojejunostomy strictures is technically feasible but is associated with higher rates of stent migration (21%) than described in the literature. As the migrated stents were only 4 cm long, use of longer fenestrated stents, with greater apposition to the hepatic ducts, may be helpful to avoid that complication.

Abstract TP81: Flow Independent Dynamics in Aneurysm (FIDA): Pressure Measurements within an Aneurysm Before and After Partial and Complete Flow Impairment

BACKGROUND: The correlation between different hemodynamic variables and aneurysm growth and rupture has not been fully understood. We aimed to study intravascular and peri-vascular pressure in the aneurysm after partial and complete flow impairment within the aneurysm. MATERIALS AND METHODS: A silicone model of an 8 mm sized aneurysm (neck diameter: 5mm, vessel size: 4 mm) was used. The aneurysm wall was encapsulated and sealed within a 5ml syringe filled with saline and a pressure sensor guidewire (PrimeWire, Volcano Corp.) providing pressure changes in the peri-vascular compartment (outer aneurysm wall). Through a 5 F guiding catheter, a second pressure sensor guidewire was advanced inside the aneurysm sac. The aneurysm connected to a pulsatile fluid pump. Both pressure sensors continuously measured pressure inside and outside the aneurysm under pulsatile flow under the following conditions: 1) baseline (reference); 2) a 16 mm by 3.75 mm flow diverting stent (ev3, Irvine, California) deployed in front of the aneurysm; 3) two flow diverting stents (16 mm by 3.5 mm) were deployed; and 4) a covered stent (4 mm by 16 mm VeriFlex cronory artery stent covered with rubber sheet) was deployed. RESULTS: Mean baseline pressures inside and outside the aneurysm were 55 mmHg (range 120-40 mmHg) and 15 mmHg (range 40-8 mmHg), respectively. There was no change in pressure inside and outside the aneurysm after deploying the first and second flow diverting stents (partial flow impairment) and pressure remained at 55 mmHg and 15 mmHg inside and outside the aneurysm, respectively. The pressure recording from outside the aneurysm dropped from 15mmHg to zero after deploying the covered stent (complete flow impairment). There was no change in pressure inside the aneurysm after deploying the covered stent. Mean pressure within the aneurysm was 55 mmHg and it remained the same after covered stent deployment. CONCLUSION: Our findings suggest a major discordance between the pressures within the aneurysm and partial or complete flow impairment (flow-independent). The outer wall pressure is reduced after covered stent placement. These finding may assist physicians in better understanding of aneurysm hemodynamics and rupture after flow diverting stent deployment.

Endovascular pseudoaneurysm repair after distal pancreatectomy with celiac axis resection

Erosive hemorrhage due to pseudoaneurysm is one of the most life-threatening complications after pancreatectomy. Here, we report an extremely rare case of rupture of a pseudoaneurysm of the common hepatic artery (CHA) stump that developed after distal pancreatectomy with en block celiac axis resection (DP-CAR), and was successfully treated through covered stent placement. The patient is a 66-year-old woman who underwent DP-CAR after adjuvant chemoradiotherapy for locally advanced pancreatic body cancer. She developed an intra-abdominal abscess around the remnant pancreas head 31 d after the surgery, and computed tomography (CT) showed an occluded portal vein due to the spreading inflammation around the abscess. Her general condition improved after CT-guided drainage of the abscess. However, 19 d later, she presented with melena, and CT showed a pseudoaneurysm arising from the CHA stump. Because the CHA had been resected during the DP-CAR, this artery could not be used as the access route for endovascular treatment, and instead, we placed a covered stent via the inferior pancreaticoduodenal artery originating from the superior mesenteric artery. After stent placement, cessation of bleeding and anterograde hepatic artery flow were confirmed, and the patient recovered well without any further complications. CT angiography at the 6-mo follow-up indicated the patency of the covered stent with sustained hepatic artery flow. To our knowledge, this is the first reported case of endovascular repair of a pseudoaneurysm that developed after DP-CAR.