Short-interval recanalization after gelfoam occlusion.

Gelfoam® is a temporary embolization agent often used in trauma where permanent arterial occlusion is not desired. Gelfoam occlusions have been shown to resolve by 2 weeks, but shorter intervals have not been studied. We report a case of spontaneous arterial hemorrhage due to ruptured hepatic malignancy where treatment was Gelfoam slurry occlusion of the right hepatic artery. Repeat hemorrhage resulted in repeat CT and hepatic arteriography, which showed that recanalization of the occluded artery had occurred in less than 48 hours. Gelfoam arterial occlusion in some cases may last less than 2 weeks.

Activation of stem cell up-regulation/mobilization: a cardiovascular risk in both mice and humans with implications for liver disease, psoriasis and SLE.

Experimentally induced injury triggers up-regulation and mobilization of stem cells in Apoe -/- mice that causes accelerated atherosclerosis. Abca1 -/- Abcg1-/- mice have chronic activation of stem cell up-regulation/mobilization and accelerated atherosclerosis. In addition, the Abca1 -/- Abcg1-/- mice have elevation of serum cytokines G-CSF, IL-17 and IL-23, each necessary for stem cell mobilization. IL-17 and IL-23 are elevated in two human illnesses that have cardiovascular (CV) risk independent of traditional risk factors-SLE and psoriasis. Serum G-CSF, which can be elevated in liver disease, predicts major adverse cardiovascular events in humans. These serum cytokine elevations suggest activation of the stem cell mobilization mechanism in humans that results, as in mice, in accelerated atherosclerosis. Efforts to reduce CV disease in these patient populations should include mitigation of the diseases that trigger stem cell mobilization. Since activation of the stem cell up-regulation/mobilization mechanism appears to accelerate human atherosclerosis, use of stem cells as therapy for arterial occlusive disease should distinguish between direct administration of stem cells and activation of the stem cell up-regulation/mobilization mechanism.

Hypersplenism in liver disease and SLE revisited: current evidence supports an active rather than passive process.

BACKGROUND: Active and passive theories have been advanced to explain splenomegaly and cytopenias in liver disease. Dameshek proposed active downregulation of hematopoiesis. Doan proposed passive trapping of blood components in a spleen enlarged by portal hypertension. Recent findings do not support a passive process. DISCUSSION: Cytopenias and splenomegaly in both liver disease and systemic lupus erythematosus (SLE) poorly correlate with portal hypertension, and likely reflect an active process allocating stem cell resources in response to injury. Organ injury is repaired partly by bone-marrow-derived stem cells. Signaling would thus be needed to allocate resources between repair and routine marrow activities, hematologic and bone production. Granulocyte-colony stimulating factor (G-CSF) may play a central role: mobilizing stem cells, increasing spleen size and downregulating bone production. Serum G-CSF rises with liver injury, and is elevated in chronic liver disease and SLE. Signaling, not sequestration, likely accounts for splenomegaly and osteopenia in liver disease and SLE. The downregulation of a non-repair use of stem cells, bone production, suggests that repair efforts are prioritized. Other non-repair uses might be downregulated, namely hematologic production, as Dameshek proposed. SUMMARY: Recognition that an active process may exist to allocate stem-cell resources would provide new approaches to diagnosis and treatment of cytopenias in liver disease, SLE and potentially other illnesses.

Cancer-free survival and local tumor control after impendence-based radiofrequency ablation of biopsy-proven renal cell carcinomas with a minimum of 1-year follow-up.

OBJECTIVES: There are numerous reports describing the use of radiofrequency ablation (RFA) to treat renal cell carcinoma. Many series, however, describe heterogeneous populations, lack histologic descriptions, use various RFA systems, and indicate tumor destruction by different ablation end points. This study examined the outcomes of computed tomography-guided, impedance-based RFA of biopsy-proven renal cell carcinoma clinically staged as T1a with a minimum of 1 year of postablation follow-up. METHODS AND MATERIALS: This retrospective study identified all consecutive patients who had undergone renal RFA since May 2005 at our institution. Patients without biopsy-proven renal cell carcinoma (RCCa) were excluded. Of the patients who met these criteria, evaluation was limited to patients with a minimum of 12 months of follow-up. Data collected from the patients' electronic medical and radiologic records included demographic data, tumor-related data, procedural details, and clinical follow-up visits. RESULTS: A total of 39 patients (46 lesions) met the inclusion criteria. The mean tumor diameter was 2.6 cm (range: 1.2-4.0 cm). The most common histologies were clear cell (n = 27) and papillary (n = 16) renal cancer. The lesion location was equally divided between upper pole (n = 16), middle pole (n = 16), and lower pole (n = 14). Overall, 83% of the tumors were exophytic. No residual or recurrent enhancing mass was identified in the ablation bed on post-RFA imaging during the mean follow-up period of 35.3 months (range: 12-83). All patients were treated in a single encounter and no lesion required a second ablation; technical success (absence of residual tumor) on the initial post-RFA imaging study was 46 of 46 (100%). Clinical success was achieved in 45 of 46 lesions (98%); residual, viable tumor was found in a pretransplant nephrectomy specimen on postprocedure day 127. The mean cancer-free survival was 36.2 months. Comparison of preablation and postablation renal function found no statistically significant change. CONCLUSIONS: The consistent outcomes in our post-RFA imaging and clinical surveillance allow us to offer image-guided ablation to patients with T1a RCCa as a valid treatment option offering long-term cancer-free survival. Impedance-based RFA in a carefully selected patient population with T1a RCCa is a reliable treatment option, with disease-free survival rates that are comparable to partial nephrectomy.

Implantable subcutaneous venous access devices: is port fixation necessary? A review of 534 cases.

Conventional surgical technique of subcutaneous venous port placement describes dissection of the port pocket to the pectoralis fascia and suture fixation of the port to the fascia to prevent inversion of the device within the pocket. This investigation addresses the necessity of that step. Between October 8, 2004 and October 19, 2007, 558 subcutaneous chest ports were placed at our institution; 24 cases were excluded from this study. We performed a retrospective review of the remaining 534 ports, which were placed using standard surgical technique with the exception that none were sutured into the pocket. Mean duration of port use, total number of port days, indications for removal, and complications were recorded and compared with the literature. Mean duration of port use was 341 days (182,235 total port days, range 1-1279). One port inversion/flip occurred, which resulted in malfunction and necessitated port revision (0.2%). Other complications necessitating port removal included infection 26 (5%), thrombosis n = 2 (<1%), catheter fracture/pinch n = 1 (<1%), pain n = 2 (<1%), and skin erosion n = 3 (1%). There were two arrhythmias at the time of placement; neither required port removal. The overall complication rate was 7%. The 0.2% incidence of port inversion we report is concordant with that previously published, although many previous reports do not specify if suture fixation of the port was performed. Suture fixation of the port, in our experience, is not routinely necessary and may negatively impact port removal.

Tunneled hemodialysis catheter outcomes in elderly patients.

PURPOSE: This retrospective study evaluated tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis. MATERIALS AND METHODS: Patients aged 75 years or older receiving hemodialysis comprised the study group. A control group of patients 40-60 years of age was randomly selected from the same dialysis quality assurance database. Demographic data, medical comorbidities, and catheter-specific data regarding indwelling time, function, interventions, and complications were recorded. RESULTS: Sixty-nine tunneled catheters were identified in 23 patients who comprised the study group (13 men and 10 women; mean age, 81.3 years; range, 75-88 y). The mean number of catheters per patient was three (range, 1-8). The mean indwelling time was 137.4 days (range, 2-622 d). Seventy-eight catheters were identified in the control group (n = 29; 14 men and 15 women; mean age, 50.6 years; range, 41-59 y). The mean number of catheters per patient was 2.7 (range, 1-9). The mean indwelling time was 139.7 days (range, 1-994 d). There was no statistically significant difference in the mean number of catheters per patient (P = .83) or the mean indwelling time (P = .93) between the two groups. There was no significant difference between the two groups in the indications for catheter removal or exchange: infection (P = 1.0), catheter no longer needed (P = 1.0), and physical catheter malfunction (P = .48). The calculated infection rates in the elderly patient and younger control groups were 0.30 per 100 catheter-days and 0.26 per 100 catheter-days, respectively. CONCLUSIONS: Tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis do not vary significantly compared with those in a younger cohort.

Dialysis access venous stenoses: treatment with balloon angioplasty--1- versus 3-minute inflation times.

PURPOSE: To examine prospectively the effects of balloon inflation time on the technical success of balloon angioplasty in dialysis access venous stenosis and on postintervention primary patency. MATERIALS AND METHODS: The study design was approved by the institution's Committee for the Protection of Human Subjects, and informed consent was obtained. Demographic information and access-specific data were collected. Patients with thrombosis, prior stent placement within the access circuit, and allergy to heparin were excluded. Patients were randomly assigned to a balloon inflation time of either 1 or 3 minutes. Balloon sizing, inflation pressure, balloon type, and heparin administration were controlled variables. The technical success of the angioplasty, defined as less than 30% residual stenosis, was evaluated for each lesion. RESULTS: A total of 48 patients were enrolled: 27 patients (40 stenoses) randomly assigned to the 1-minute group and 21 (36 stenoses) to the 3-minute group. There were no significant demographic differences between the two inflation groups. Technical success rates in the 1- and 3-minute inflation groups were 75% and 89%, respectively. Logistic regression analysis, which controlled for patient age, sex, and age of the access, demonstrated that technical success was 4.7 times more likely in the 3- versus the 1-minute inflation group (95% confidence interval: 1.1, 20.1). The 1-, 3-, and 6-month postintervention patencies were not significantly different between the two groups. CONCLUSION: Although a 3-minute inflation time significantly improved the likelihood of technical success for percutaneous transluminal angioplasty of dialysis access venous stenoses, there was no significant difference in postintervention access patency.

Endovascular stent-graft or open surgical repair for blunt thoracic aortic trauma: systematic review.

PURPOSE: To evaluate the available data on stent-graft repair of acute blunt traumatic thoracic aortic injury with regard to safety and efficacy compared with conventional open surgical repair. MATERIALS AND METHODS: The literature on endovascular repair of acute traumatic aortic injury since 1990 was systematically reviewed. Metaanalysis of publications with open and stent-graft repair cohorts was performed to evaluate whether there was a difference in treatment effect with regard to mortality and paraplegia. Case series were included to obtain an adequate population to assess the incidence of stent-graft procedure-related complications. RESULTS: There were no prospective randomized studies. Nineteen publications that compared the outcomes of 262 endograft repairs and 376 open surgical repairs were identified. The odds ratio for mortality after endovascular versus open repair was 0.43 (95% CI, 0.26-0.70; P = .001). The odds ratio for paraplegia after endovascular versus open repair was 0.30 (95% CI, 0.12-0.76; P = .01). In the pooled group of 667 endovascular repair survivors from 50 reports, the incidence of early endoleak was 4.2%, and late endoleak occurred in 0.9%. Stroke or transient ischemic attack was reported in 1.2%. Access site complications that required intervention occurred in 4.1%. CONCLUSIONS: The available cohort and case series data support stent-graft repair as a highly successful technique that may reduce mortality and paraplegia rates by half compared with open surgery. These data support endograft repair as first-line therapy for blunt thoracic aortic trauma.

Selective palliative transcatheter embolization of bony metastases from renal cell carcinoma.

To examine whether transcatheter embolization of bone metastases is an effective palliative option for patients with renal cell carcinoma (RCCa). A retrospective review of 21 patients presenting for palliative embolization of painful RCCa skeletal metastases was performed. Details regarding anatomic sites, procedural details, and embolization materials were collected. The clinical response of the patient was assessed from clinic visits and analgesic use. Thirty separate embolization procedures were used to treat 39 metastatic lesions (18 pelvic, 8 lower extremity, 3 upper extremity, 5 rib/chest well, and 5 vertebral lesions). Five patients underwent more than one embolization. Polyvinyl alcohol was used in all 30 embolization procedures. Additional embolic materials were used in 16 of 30 procedures. A clinical response was achieved at 36 treated sites; the mean duration fo the response was 5.5 months. Selective embolization of bony renal cell carcinoma metastases can provide effective palliation in a patient population which has limited therapeutic options.

Pericardial tamponade in patients with central venous catheters.

Cardiac (pericardial) tamponade occurs when the pressure of the fluid within the pericardial sac is high enough to impair the venous return to the heart. Cardiac tamponade can occur during central venous catheter placements. Nursing members of a central vascular catheter placement team benefit from quickly recognizing this clinical situation and understanding the appropriate clinical response. A methodical approach to this potentially fatal condition can greatly increase patient safety. This article reviews this condition, its clinical presentation and diagnosis, and strategies for avoiding central vascular access-associated tamponade.

Sclerosis of postoperative lymphoceles: avoidance of prolonged catheter drainage with use of a fibrin sealant.

PURPOSE: To review experience with fibrin-based tissue sealant sclerosis of postsurgical lymphoceles at a single institution. MATERIALS AND METHODS: Fifteen patients who presented with postsurgical lymphoceles were treated with injection of fibrin tissue sealant. Procedures were performed under fluoroscopic and sonographic guidance. All lymphoceles were drained and sclerosed with a mixture of fibrin sealant and gentamicin. No drainage catheter was left in place. Postprocedural follow-up consisted of imaging and clinical evaluations. RESULTS: Twelve men and three women (mean age, 52 years) were treated. Eleven patients with lymphoceles were successfully treated with one session of sclerosis. Four patients required more than one treatment (two underwent two sessions, and two underwent three sessions). Seven patients undergoing a single treatment experienced complete resolution, and the remaining patients had smaller, persistent, asymptomatic collections. Imaging mean follow-up was 114 days (range, 5-339 d); mean clinical follow-up was 487 days (range, 195-856 d). There were no periprocedural complications. CONCLUSION: The use of fibrin sealant is safe and effective in the sclerosis of postoperative lymphoceles.

Jugular vein catheter placement: histologic features and development of catheter-related (fibrin) sheaths in a swine model.

PURPOSE: To evaluate the development and histologic features of jugular vein catheter-related (fibrin) sheaths in a swine model. MATERIALS AND METHODS: The proposal was approved by the University Committee on the Use and Care of Animals. Tunneled silicone 7-F catheters were placed via a jugular vein in eight swine. The animals were separated into four groups of two pigs each according to catheter indwelling times of 7, 14, 30, and 45 days. After the animals were sacrificed, the catheter, access vein, and cranial vena cava were dissected, removed en bloc, and fixed in formalin. Histologic evaluation was performed by using standard light microscopy on hematoxylin-eosin stained specimens; immunohistochemistry was also performed to confirm specific cell populations. RESULTS: Catheter-related sheaths that covered 33%-100% of the intravascular catheter length were identified in all eight catheter specimens. After 7 days, catheters had a partial or circumferential mixed cellular and noncellular covering consisting of smooth muscle cells, thrombus, and areas with endothelial cell populations. Sheaths from catheters excised at 14 days were characterized by prominent endothelial cell and smooth muscle cell proliferation. Catheters excised at 30 and 45 days showed less prominent cellularity and more prominent collagen content, in a well-developed sheath, than did those excised at 7 and 14 days. With longer catheter indwelling times, an endothelial layer, indistinguishable from the adjacent vein wall, covered the catheter surface. CONCLUSION: The sheath that develops around central venous catheters in the swine model consists of cellular and noncellular components. A substantial proportion of the sheath is made up of a smooth muscle cell and collagen layer with overlying endothelial cells.

Conformation of adjacent self-expanding stents: a cross-sectional in vitro study.

We examined the proximal conformation of three commonly used self-expanding stents when the stents were deployed adjacent to one another in a tubular model, simulating a "kissing" stent technique. The stent pairs were evaluated by computed tomogrphy to determine the cross-sectional area excluded by the stents within the model. The mean areas associated with each stent pair were compared and significance evaluated by a t-test. A statistically significant difference was found when the area excluded by adjacent Wallstents was compared with both the Luminexx and SMART stents (p < 0.001 and p < 0.002, respectively). The difference in the area excluded and differences in conformation might play a role in the lower patencies that have been observed in "kissing" stent series.

Successful angioplasty of a superficial femoral artery stenosis caused by a suture-mediated closure device.

We report the successful angioplasty of an acute arterial narrowing after suture-mediated closure (SMC) of a femoral arterial puncture. A 75-year-old woman underwent a cerebral arteriogram via a right common femoral artery puncture. The arteriotomy site was closed with a SMC device. Four days after placement the patient complained of pain in her right calf after walking. An arteriogram 7 days after SMC showed a severe focal stenosis at the origin of the superficial femoral artery involving the presumed puncture site. The lesion was successfully treated with balloon angioplasty. The patient at 6 months was asymptomatic.

Histologic changes in the human vein wall adjacent to indwelling central venous catheters.

PURPOSE: Central venous catheter dysfunction can be caused by thrombosis (of the catheter or vessel itself), fibrin sheath formation, or infection. These sequelae can lead to costly interventions, loss of the access device, or loss of access sites in as many as one-third of patients. This study examined the histologic changes in the access vein and superior vena cava wall that is adjacent to central venous catheters in humans. MATERIALS AND METHODS: The access vein, brachiocephalic vein, and superior vena cava were excised en bloc at autopsy from six patients with central venous catheters. The specimens were processed and stained with hematoxylin and eosin. The specimens were examined for histologic changes in the vein wall adjacent to the catheters, changes in the intima, and the presence of associated thrombus. RESULTS: Three catheters had been in place <14 days (short term), and three for >90 days (long term). Two microscopic patterns were observed. The short-term catheters displayed foci of local intimal injury with endothelial denudation and a layer of adherent thrombus. The second pattern, seen in the long-term catheters, consisted of smooth muscle cell proliferation leading to vein wall thickening. Focal areas of catheter attachment to the vein wall, composed of thrombus in varying stages of organization, collagen, and endothelial cells, were also observed. CONCLUSIONS: After short-term catheter placement, focal areas of endothelial injury were seen in the vein wall adjacent to the catheter. Associated thrombus may or may not be present. Long-term catheters displayed vein wall thickening and bridges from the vein wall to the catheter. These observations represent a progressive reaction of the human vein wall to access devices.