Elevated levels of endothelin-1 in hepatic venous blood are associated with intrapulmonary vasodilatation in humans.

BACKGROUND: Hepatopulmonary syndrome is a pulmonary vascular complication of cirrhosis in which intrapulmonary vasodilatation (IPV) results in hypoxemia. Endothelin-1 (ET-1), produced by proliferating cholangiocytes, has been identified as a mediator of IPV in an animal model of HPS, but the pathophysiology of IPV in humans has not been defined. AIM: The purpose of this study was to assess whether cirrhosis with IPV, which often leads to HPS, is associated with increased hepatic venous ET-1 blood levels. METHODS: We performed a prospective cohort pilot study of 40 patients with liver disease undergoing transjugular liver biopsy from November 1, 2008 to September 1, 2009. Patients were categorized according to absence (-) or presence (+) of IPV as determined by bubble-contrasted echocardiography. Hepatic venous blood was assayed for ET-1 by ELISA. The percent volume of cholangiocytes in the liver biopsy specimen was determined by morphometric analysis, as a measure of bile duct proliferation. RESULTS: Nine subjects were excluded, due to absence of cirrhosis (6) and patent foramen ovale (3). Of the remaining 31 subjects, IPV was present in 18 (58%). Median hepatic venous ET-1 was higher with IPV+ than IPV- at levels of 9.1 pg/mL (range 7.5-11.7) versus 2.1 pg/mL (1.3-5.6), respectively (P = 0.004). ET-1 levels correlated positively with cholangiocyte percent volume (r = 0.72, P < 0.001) but not with measures of liver dysfunction (bilirubin, INR, MELD score, or hepatic venous pressure gradient). CONCLUSION: In human cirrhosis, increased hepatic venous ET-1 is associated with IPV and increased hepatic cholangiocyte volume.

Angiographic and histologic comparison of injectable, expansile hydrogel embolic and pushable AZUR embolic devices in porcine arteries.

PURPOSE: To compare an injectable hydrogel embolic device with a pushable AZUR device procedurally, angiographically, and histologically in the embolization of porcine arteries. MATERIALS AND METHODS: In 12 pigs, embolization of renal, gluteal, and hepatic or thoracic arteries was performed with either injectable hydrogel embolic devices (two arteries per pig) or an AZUR device (one artery per pig). Follow-up angiography was performed before sacrifice in five pigs at 7 days after embolization and seven pigs at 90 days after embolization. The harvested tissues were evaluated histologically. Continuous and ordinal results were compared using analysis of variance and χ(2) tests. RESULTS: For the sites with embolization performed with injectable hydrogel, complete angiographic occlusion was obtained in 21 of 24 (88%) sites after treatment, 10 of 10 (100%) sites at 7 days, and 10 of 14 (72%) sites at 90 days. For the sites with embolization performed with AZUR devices, complete angiographic occlusion was obtained in 10 of 12 (83%) sites after treatment, 4 of 5 (80%) sites at 7 days, and 5 of 7 (72%) sites at 90 days. Statistically significant differences in angiographic occlusion were not observed at 7 days (P = .13) or 90 days (P = .35). The embolization time of the injectable hydrogel group (14 minutes ± 8) was significantly reduced (P = .02) compared with the AZUR group (22 minutes ± 12). Differences between the groups in arterial wall damage were not evident at either 7 days or 90 days, although greater damage was observed in both groups at 90 days. In both groups, inflammation was nonexistent to minimal at 7 days and minimal to mild at 90 days. CONCLUSIONS: Embolization of porcine arteries was as effective with injectable hydrogel embolic devices as pushable AZUR devices, as evidenced by the procedural, angiographic, and histologic results.

Predictive factors for the development of type II endoleaks.

PURPOSE: To define predictive factors for endoleak type II (EL-II) based on quantifiable factors in the imaging studies of patients undergoing endovascular aneurysm repair (EVAR). METHODS: The data on 208 consecutive patients (137 men; mean age 75.2 years, range 62-84) who underwent EVAR between the years 2003 and 2008 were retrospectively reviewed. The abdominal aortic aneurysm (AAA) diameter ranged from 4.8 to 12.8 cm. Data were collected on the type of AAA; the type of stent-graft (aortomonoiliac versus bifurcated); the performance of hypogastric artery embolization; the presence, number, diameter, and patency of aortoiliac branches identified on the pre and post-EVAR imaging studies; and the presence and type of EL-II (transient vs. persistent) with the goal of identifying any imaging-based predictive factors for the development of EL-II. RESULTS: Among the 208 cases, 11 patients had endoleaks other than type II and were excluded, leaving 195 patients for analysis. In all, 28 (13.4%) patients were diagnosed with EL-II. All had ≥4 patent lumbar arteries (mean diameter >2.3 mm). Ten patients with a transient EL-II had a mean of 4.3 patent lumbar arteries, which had diameters <2 mm (mean 1.5 mm). In the 18 patients with persistent EL-II, the mean diameter of the 4 lumbar arteries was 2.7 mm; at least 1 of the lumbar arteries was >2 mm. The presence of at least 4 patent lumbar arteries (p<0.001) and at least 1 patent hypogastric artery (p<0.001) were predictive factors for EL-II. At least 1 lumbar artery >2 mm in diameter was a positive predictive factor for the development of persistent EL-II (p<0.001). CONCLUSION: Patent hypogastric and lumbar arteries are significantly associated with a higher risk of developing EL-II. Larger diameter lumbar arteries tend to be associated with persistent EL-IIs, while lumbar arteries <2 mm would more likely be seen with a transient EL-II. If substantiated in larger studies, these angiographic criteria may guide early treatment of EL-II to avoid aneurysm sac expansion and potential rupture.

Percutaneous transhepatic islet cell autotransplantation after pancreatectomy for chronic pancreatitis: a novel approach.

BACKGROUND: In selected patients with chronic pancreatitis, extensive pancreatectomy can be effective for the treatment of intractable pain. The resultant morbid diabetes can be ameliorated with islet autotransplantation (IAT). Conventionally, islet infusion occurs intraoperatively after islet processing. A percutaneous transhepatic route in the immediate postoperative period is an alternative approach. METHODS: A prospectively collected database of patients undergoing pancreatectomy with percutaneous IAT (P-IAT) was reviewed. Hospital billing data were obtained and median charges determined and compared with estimated charges for an intraoperative infusion method of IAT (I-IAT). RESULTS: Thirty-six patients (28 women; median age 48 years) underwent pancreatectomy with P-IAT. Median operative time was 232 min (range: 98-395 min) and median estimated blood loss was 500 cc (range: 75-3000 cc). Median time from pancreatic resection to islet transplantation was 269 min (range: 145-361 min). A median of 208 248 IEq (2298 IEq/kg) were harvested. Median peak portal venous pressure during islet infusion was 13 mmHg (range: 5-37 mmHg). Postoperative complications occurred in 15 patients (42%) and included hepatic artery pseudoaneurysm and portal vein thrombosis; the latter occurred in two patients with portal pressures during infusion > 30 mmHg. At a median follow-up of 10.7 months, eight patients (22%) were insulin-free. Median pertinent charges for P-IAT were US$36,318 and estimated median charges for I-IAT were US$56,440. Surgeon time freed by P-IAT facilitated an additional 66 procedures, charges for which amounted to US$463,375. CONCLUSIONS: Percutaneous transhepatic IAT is feasible and safe. Islet infusion in the immediate postoperative period is cost-effective. Further follow-up is needed to assess longterm results.

Locoregional therapy for hepatocellular carcinoma.

Locoregional therapies for hepatocellular carcinoma have progressed greatly in the last 30 years, beginning with the introduction of chemoembolization. Embolization techniques have evolved with the use of drug-eluting beads and radioembolization with yttrium-90. In the last 10 years, several new ablation techniques were developed including radiofrequency ablation, microwave ablation, cryoablation, laser ablation, and irreversible electroporation. Isolated or in combination, these techniques have already shown that they can improve patient survival and/or provide acceptable palliation.

The rise and fall of arterial interventions: presentations at the Society of Interventional Radiology annual scientific meeting.

PURPOSE: To address hypotheses concerning a decline in presentations pertaining to vascular interventions by interventional radiologists and the loss of ground in other areas, such as oncology, of presentations in vascular interventions at the Society of Interventional Radiology (SIR) Annual Scientific Meeting. MATERIALS AND METHODS: All abstracts for scientific presentations and scientific exhibits from the program book of the SIR annual meeting were reviewed from the period 1996-2006. The abstracts were grouped in different classes, such as (a) type of methodology, (b) reports on arterial interventions, (c) reports on oncologic interventions, and (d) geographic origin. RESULTS: Scientific abstracts presented at the SIR annual meeting totaled 3,162. Presentations ranged from 177-407 (1996-2003) plus 250 in 2006 with a mean of 288 presentations per year. The overall number of abstracts reporting arterial interventions had a peak of 89 presentations in 2000 and declined to 34 presentations in 2006. Reports of arterial interventions from the United States had a peak of 48 presentations in 2003 and declined to 12 in 2006. Reports of arterial interventions from Europe had a peak of 37 presentations in 2000 and declined to 11 in 2006. Reports of arterial interventions from Asia had a peak of 10 presentations in 1999 and declined to 6 in 2006. The trends are similar for the three components of arterial interventions when analyzed individually. In 1997, 26.6% of all the presentations were arterial interventions; in 2000, 25.1%; and in 2006, only 13.6%. There was a trend in the increase of oncology presentations starting in 2004. In 2003, it was 10%, and it was 22.4% in 2006. CONCLUSIONS: There has been a decline in the overall number of abstracts presented at the SIR annual meeting after a peak in 2003. There has been a decline in the number of arterial intervention reports. The decline in presentations of arterial interventions that originated in the United States was also observed in presentations that originated from Europe and Asia. There has been an increasing trend in interventional oncology reports starting in 2004.

Successful recanalization of bile duct occlusion with a radiofrequency puncture wire technique.

A radiofrequency (RF) wire puncture technique was used in the recanalization of biliary anastomotic occlusions in five patients. The technical success of recanalization, which was defined as successful puncture and crossing of the obstruction followed by balloon cholangioplasty and internal-external biliary drainage without evidence of complications, was 100%. The average follow-up was 13 months (range, 11-16 months). For biliary occlusion recanalization, the RF wire may allow the use of percutaneous therapy in the treatment of a subset of individuals who would otherwise have to undergo open surgical intervention.

Normal renal arterial anatomy assessed by multidetector CT angiography: are there differences between men and women?

The purpose of this study was to determine renal arterial anatomy and gender differences in adults without renovascular disease using multidetector computed tomography angiography (MDCTA). MDCTA datasets of 399 patients were retrospectively reviewed. Measurements of the aortorenal diameters, the angulation of the renal ostia and pedicles as well as the distance between the origins of the renal arteries were measured. Differences in measurements between genders were tested for statistical significance using analysis of variance (ANOVA) and Pearson's Chi-Square tests. A total of 798 renal arteries were available for analysis in 207 female (mean age = 52.91 years) and 192 male patients (mean age = 53.04 years). Female patients were found to have smaller aortae (at the level of the right renal ostium) and bilateral renal arteries than males (mean aortic diameter M/F = 18.33/15.89 mm, mean right renal artery ostial diameter M/F = 5.06/4.59 mm, mean left ostial renal diameter M/F = 5.14/4.66 mm) (p < .001). There was no statistical significance for the renal ostia level in relation to the vertebrae and the majority of renal arteries originated at the L1 and L2 levels. The longitudinal distance between right and left renal artery ostia ranged from 0 to 32 mm (mean = 4,6 mm, median = 5mm). The mean anteroposterior orientation of the right renal ostia was M/F = 29.45 degrees/28.20 degrees , and M/F = -7.96 degrees/-11.14 degrees for left renal artery ostia. The mean anteroposterior orientation of the right renal pedicle was M/F = 41.37 degrees/44.34 degrees and M/F = 42.31 degrees/43.95 degrees for the left pedicle. There are some differences in normal renal arterial anatomy between genders. Normal renal arterial information is useful not only for planning and performing of endovascular and laparoscopic urologic procedures, but also for medical device development.

Clinical experience with a customized fenestrated endograft for juxtarenal abdominal aortic aneurysm repair.

Despite the numerous stent-graft devices available, unsuitable anatomy is still the greatest exclusion criterion for endovascular abdominal aortic aneurysm (AAA) repair (EVAR). The present report describes an on-site preprocedural customization of a conventional Zenith stent-graft device just before the endovascular procedure that includes the creation of fenestrations and scallops as necessary for the patient's anatomy. Three patients with difficult anatomy in whom conventional AAA repair posed a high degree of risk were treated with customization of the stent-graft device to fit disparate renal arteries. A single fenestration for the left renal artery was made in two cases, and a single scallop was made in the other case to accommodate the superior mesenteric artery. Gold beads were used to mark the location of the fenestration and scallop. The three cases were successfully performed without perceptible endoleaks in the follow-up period, which ranged from 4 to 14 months. No procedure-related complications were detected; however, pneumonia developed in one patient 3 weeks after EVAR. The initial results with this technique are encouraging, and the role of EVAR can be significantly increased with the use of this customization technique when the interventionalist does not have access to the commercially available devices or when the waiting time is too prolonged to accommodate the patient's clinical situation.

Stent-graft treatment of pseudoaneurysms and arteriovenous fistulae in the carotid artery.

The purpose of this study was to assess the safety and efficacy of stent-graft placement in the management of arteriovenous fistulae (AVF) and pseudoaneurysms (PAs) involving the carotid artery (CA). Twenty-two patients (16 men, 6 women) with a CA AVF (n = 5) or PA (n = 17) owing to a gunshot or stab wound, carotid endarterectomy, blunt trauma, a tumor, spontaneous dissection, or a central venous catheter were treated with percutaneous placement of stent grafts. The patients presented with tumor, bruit, headache, mouth and tracheostomy bleeding, transitory hemiparesis, seizure, or stroke. Diagnoses were made by using computed tomographic angiography (CTA) and digital subtraction angiography. Fourteen lesions were in the common CA; eight were in the internal CA. Homemade devices and stent grafts from a variety of manufacturers were employed. Follow-up evaluations included clinical, CTA, and Doppler ultrasound assessments. All patients had resolution of the PA or AVF. In one patient with a large petrous PA, acute occlusion of the CA developed after placement of three balloon-expandable stent grafts, but there were no neurologic complications because the circle of Willis was functional. During follow-up ranging from 2 months to 13 years, asymptomatic 90% stenosis owing to stent compression was observed on Doppler ultrasound and angiographic examinations in a patient with an autologous vein-covered stent graft in the internal CA. Three other patients died of causes unrelated to stent-graft placement. In all other patients, the stent graft remained patent. Our results indicate that stent grafting is an acceptable alternative to surgery in the treatment of AVF and PAs in the CA.

Comparative results of Doppler sonography after TIPS using covered and bare stents.

OBJECTIVE: Our purpose was to evaluate the role of sonography in the early follow-up of patients with a covered transjugular intrahepatic portosystemic shunt (TIPS). CONCLUSION: Routine baseline Doppler sonography should occur 7-14 days after shunt placement unless malfunction or procedural complications are suspected.

Stent migration complicating treatment of inferior vena cava stenosis after orthotopic liver transplantation.

A case of inferior vena cava (IVC) stenosis after orthotopic liver transplantation was treated with balloon angioplasty and Wallstent placement. There was stent migration into the right atrium (RA), and percutaneous removal of the stent was attempted without success. Open cardiac surgery was required for stent removal and repair of aortic/RA fistula. Months later, recurrent IVC stenosis was successfully treated with placement of large Z stents after additional failed surgical repair. At 2 years follow-up, the patient is asymptomatic and Doppler ultrasonography demonstrated the stent to be patent and well-positioned.

Anatomic relationship of the internal jugular vein and the common carotid artery applied to percutaneous transjugular procedures.

PURPOSE: To demonstrate the anatomic relationship of the internal jugular vein (IJV) with the common carotid artery (CCA) in order to avoid inadvertent puncture of the CCA during percutaneous central venous access or transjugular interventional procedures. METHODS: One hundred and eighty-eight consecutive patients requiring either central venous access or interventional procedures via the IJV were included in the analysis. The position of the IJV in relation to the CCA was demonstrated by portable ultrasonography. The IJV location was recorded in a clock-dial system using the carotid as the center of the dial and the angles were measured. Outcomes of the procedure were also recorded. RESULTS: The IJV was lateral to the CCA in 187 of 188 patients and medial to the CCA in one patient. The left IJV was at the 12 o'clock position in 12 patients (6%), the 11 o'clock position in 17 patients (9%), the 10 o'clock position in 142 patients (75%) and at the 9 o'clock position in 17 patients (9%). The right IJV was at the 12 o'clock position in 8 patients (4%), the 1 o'clock position in 31 patients (16%), the 2 o'clock position in 134 patients (71%) and the 3 o'clock position in 17 patients (9%). In one patient the left IJV was located approximately 60 degrees medial to the left CCA; this was recorded as 2 o'clock on the left since it is opposite to the 10 o'clock position. CONCLUSION: Knowledge of the IJV anatomy and relationship to the CCA is important information for the operator performing an IJV puncture, to potentially reduce the chance of laceration of the CCA and avoid placement of a large catheter within a critical artery, even when ultrasound guidance is used.

Isolated right segmental hepatic duct injury following laparoscopic cholecystectomy.

PURPOSE: Laparoscopic cholecystectomy (LC) is the treatment of choice for gallstones. There is an increased incidence of bile duct injuries in LC compared with the open technique. Isolated right segmental hepatic duct injury (IRSHDI) represents a challenge not only for management but also for diagnosis. We present our experience in the management of IRSHDI, with long-term follow-up after treatment by a multidisciplinary approach. METHODS: Twelve consecutive patients (9 women, mean age 48 years) were identified as having IRSHDI. Patients' demographics, clinical presentation, management and outcome were collected for analysis. The mean follow-up was 44 months (range 2-90 months). RESULTS: Three patients had the LC immediately converted to open surgery without repair of the biliary injury before referral. Treatments before referral included endoscopic retrograde cholangiopancreatography (ERCP), percutaneous drainage and surgery, isolated or in combination. The median interval from LC to referral was 32 days. Eleven patients presented with biliary leak and biloma, one with obstruction of an isolated right hepatic segment. Post-referral management of the biliary lesion used a combination of ERCP stenting, percutaneous drainage and stent placement and surgery. In 6 of 12 patients ERCP was the first procedure, and in only one case was IRSHDI identified. In 6 patients, percutaneous transhepatic cholangiography (PTC) was performed first and an isolated right hepatic segment was demonstrated in all. The final treatment modality was endoscopic management and/or percutaneous drainage and stenting in 6 patients, and surgery in 6. The mean follow-up was 44 months. No mortality or significant morbidity was observed. CONCLUSION: Successful management of IRSHDI after LC requires adequate identification of the lesion, and multidisciplinary treatment is necessary. Half of the patients can be treated successfully by nonsurgical procedures.

Thrombosed dialysis access grafts: randomized comparison of the Amplatz thrombectomy device and surgical thromboembolectomy.

We report the final results of the trial comparing the Amplatz thrombectomy device (ATD) with surgical thromboembolectomy (ST) to declot thrombosed dialysis access grafts (DAG). The study population consisted of 174 DAG, 109 of which were randomized to mechanical thrombectomy using the ATD and 65 of which were randomized to conventional surgical thromboembolectomy. Forty grafts were re-enrolled in the trial when they failed beyond the 90 days follow-up after the initial treatment. Thirty-one were re-enrolled for mechanical thrombectomy and nine were re-enrolled for surgical thrombectomy, resulting in a total of 140 ATD procedures and 74 surgical thromboembolectomy. Immediate thrombectomy success was defined as greater than 90% thrombus removal followed by the ability to dialyze after treatment, and analysis of long term success based on graft patency at 30 and 90 days, with successful dialysis. Immediate thrombectomy success with the ATD procedure was achieved in 79.2% and with ST in 73.4%. Patency of the graft, with successful dialysis, at 30 days with the ATD procedure was 79.2% and with ST was 73.4%. Patency of the graft, with successful dialysis, at 90 days with the ATD procedure was 75.2% and with ST was 67.8%. The data collected in this study provided a prospective comparison of mechanical thrombectomy with the ATD and ST performance in thrombosed DAG. The results of the performance of both methods were comparable. No statistically significant differences were seen.

Angiographic findings in biliary atresia.

We present the angiographic findings of 46 patients with biliary atresia (BA). There were 25 males and 21 females, with a mean age of 22.5 months (range - 1.5 to 141 months). Hepatic and mesenteric angiography were obtained as part of a liver transplantation work-up or as part of the treatment of clinical events. All patients had a histological diagnosis of BA. The portal vein was patent in 43 patients, with a mean size of 4.1 mm, using the arterial catheter as comparison. Portal hepatopetal flow was observed in 20 patient and hepatofugal flow was observed in 21 patients. Presence of gastroesophageal varices was observed in 41 patients. The hepatic artery was enlarged in all patients. In all 46 patients studied, the intrahepatic peripheral hepatic artery branches presented with irregularities in contour, including encasement, strictures, dilatation and angulation, and images suggestive of peripheral occlusion. Angiographic vascular "tuft-like" blush surrounding the irregular or occluded peripheral arterial segments was observed in 40 patients. The injection of Microfil in one case showed a marked vascular proliferation within the portal tract, apparently derived from arterial and portal connections, filling the entire portal space. We conclude that the presence of angiographically demonstrable perivascular arterial tufts in the periphery of the hepatic arterial circulation is a common finding in cases of BA, and may be a characteristic diagnostic angiographic finding.

Applications of percutaneous mechanical thrombectomy in transjugular intrahepatic portosystemic shunt and portal vein thrombosis.

Portal vein thrombosis (PVT) is an uncommon cause for presinusoidal portal hypertension. PVT can be caused by one of three broad mechanisms: (1) spontaneous thrombosis when thrombosis develops in the absence of mechanical obstruction, usually in the presence of inherited or acquired hypercoagulable states; (2) intrinsic mechanical obstruction because of vascular injury and scarring or invasion by an intrahepatic or adjacent tumor; or (3) extrinsic constriction by adjacent tumor, lymphadenopathy or inflammatory process. Usually, several combined factors are necessary to result in PVT. The consequences of portal vein thrombosis are mostly related to the extension of the clot within the vein. Gastrointestinal bleeding from gastroesophageal varices is the most frequent presentation. Noninvasive imaging techniques are currently used for the screening of patients and the initial diagnosis of PVT. The invasive techniques are reserved for cases when noninvasive techniques are inconclusive, before percutaneous interventional treatment, or in preoperative assessment of patients who are candidates for surgery. Recanalization of the portal vein with anticoagulation alone may not be consistent or appropriate in highly symptomatic patients. Catheterization of the superior mesenteric artery (SMA) is helpful for diagnosis as well as for therapy by allowing the intra-arterial infusion of thrombolytic drugs in the same setting. Direct transhepatic portography allows precise determination of the degree of stenosis and extension within the portal vein, as well as pressure measurements. Thrombotic occlusions of the portal, mesenteric, and splenic veins can be managed by mechanical thrombectomy (MT) or pharmacologic thrombolysis. Underlying occlusions because of organized or refractory thrombus or fixed venous stenosis are best corrected by balloon angioplasty and stent placement. Access into the portal venous system can also be established through creating a transjugular intrahepatic portosystemic shunt (TIPS). Creating a TIPS is also important in the setting of PVT associated with cirrhosis to decompress portal hypertension and improve portal venous flow. PVT involving the portal, splenic, and/or mesenteric veins can also complicate a preexisting TIPS in which case the shunt can be readily used as therapy access. Several techniques may be used to recanalize the shunt and portal venous system, including thrombolytic therapy, balloon angioplasty/embolectomy, suction embolectomy, basket extraction of clots, and mechanical thrombectomy with a variety of devices. Advantages of MT include the potential to rapidly remove thrombus without the need for prolonged thrombolytic infusions, and reducing the potential life-threatening complications of thrombolytic therapy. Possible drawbacks include the risk of intimal or vascular trauma to the portal vein, which may promote recurrent thrombosis.