Direct translumbar inferior vena cava ports for long-term central venous access in patients with cancer

PURPOSE

To evaluate the indications, complications, and long-term results of translumbar port placements to the inferior vena cava for long-term central venous access in a single tertiary center.

MATERIALS AND METHODS

This retrospective study included all patients with cancer who underwent translumbar port placement from January 2000 to July 2012; 31 patients (all women) with an average age of 53.1 years ± 11.1 (range, 30-77 y) were included in the study. Of these patients, 26 (81%) had breast cancer, 3 had lung cancer, 1 had ovarian cancer, and 1 had rectal cancer. Indications included central venous occlusion in 9 patients (29%) and bilateral mastectomy and lymph node dissection in 22 patients (71%).

RESULTS

All procedures were technically successful. The overall 30-day complication rate was 9.7% (n = 3). Average catheter use was 14.1 months ± 21 (range, 0.75-108 mo). Thirteen (41.9%) ports were removed because they were no longer needed; 4 (12.9%) ports required removal for port malfunction; 12 (38.7%) patients died with their ports still in place; 2 (6.5%) ports remain in use. Three (9.7%) ports required delayed secondary intervention to remain functional. One patient had a systemic infection attributed to the port, resulting in an overall infection rate of 0.08 per 1,000 catheter days.

CONCLUSIONS

Translumbar inferior vena cava port placement is a technically feasible and safe alternative method for long-term central venous access.

Native portal vein embolization for persistent hyperoxaluria following kidney and auxiliary partial liver transplantation

Type 1 primary hyperoxaluria (PH1) causes renal failure, for which isolated kidney transplantation (KT) is usually unsuccessful treatment due to early oxalate stone recurrence. Although hepatectomy and liver transplantation (LT) corrects PH1 enzymatic defect, simultaneous auxiliary partial liver transplantation (APLT) and KT have been suggested as an alternative approach. APLT advantages include preservation of the donor pool and retention of native liver function in the event of liver graft loss. However, APLT relative mass may be inadequate to correct the defect. We here report the first case of native portal vein embolization (PVE) to increase APLT to native liver mass ratio (APLT/NLM-R). Following initial combined APLT-KT, both allografts functioned well, but oxalate plasma levels did not normalize. We postulated the inadequate APLT/NLM-R could be corrected by trans-hepatic native PVE. The resulting increased APLT/NLM-R decreased serum oxalate to normal levels within 1 month following PVE. We conclude that persistently elevated oxalate levels after combined APLT-KT for PH1 treatment, results from inadequate relative functional capacity. This can be reversed by partial native PVE to decrease portal flow to the native liver. This approach might be applicable to other scenarios where partial grafts have been transplanted to replace native liver function.

Identification of small compound biomarkers of pituitary adenoma: a bilateral inferior petrosal sinus sampling study

Evaluation of the pathogenic mechanisms underlying Cushing disease (CD) is limited partly by the inaccessibility of the pituitary gland for biopsy. We used bilateral inferior petrosal sinus sampling (BIPSS), the gold standard in diagnosing pituitary sources of CD, to obtain central blood samples for in vivo metabolomic analysis of pathways involved in pituitary adenomas. We evaluated 16 samples from eight patients who underwent BIPSS to measure adrenocorticotropic hormone (ACTH) levels in the inferior petrosal sinus (IPS) bilaterally. Seven patients had CD with concordant BIPSS, surgical, and pathologic findings. Samples from the IPS contralateral to histologically proven lesions were used as controls. BIPSS of the eighth patient revealed no central pituitary ACTH source, and these samples were also included as controls. Plasma samples were profiled using a combination of three liquid chromatography tandem mass spectrometry methods, which assessed 259 metabolites. Following Bonferroni correction for multiple comparisons, three small compound biomarkers of CD (pyridoxate, deoxycholic acid, and 3-methyladipate) were identified to be significantly altered in pituitary adenomas. The pathway most significantly impacted in CD samples is one previously shown to be upregulated in other cancers. Exploiting the BIPSS technique, we showed a complete metabolite and lipid profile of pituitary adenomas in CD. These potential biomarkers of CD may elucidate tumor biology and suggest possible diagnostic molecular imaging probes as well as therapeutic targets in patients with recurrent disease after surgery.

Safety and effectiveness of chemoembolization with drug-eluting beads for advanced-stage hepatocellular carcinoma

BACKGROUND

According to the Barcelona Clinic Liver Cancer (BCLC) algorithm, patients with advanced stage (BCLC-C) hepatocellular carcinoma (HCC) are recommended for systemic treatment or palliative therapy. However, chemoembolization with drug-eluting beads (DEB-TACE) has been shown to be safe in high-risk patients. The purpose of our study was to evaluate the safety and effectiveness of DEB-TACE in patients with an advanced-stage HCC.

METHODS

In this institutional review board-approved, retrospective study, 80 patients with advanced-stage HCC underwent DEB-TACE with doxorubicin. Patients were evaluated for median hospital stay, incidence of Grade 3/4 toxicities, 30-day mortality, progression-free survival (PFS), and overall survival (OS) following DEB-TACE. Univariate and multivariate analysis were performed for predictors of better OS.

RESULTS

The median hospital stay following DEB-TACE was 1 day (range: 1-11). The median PFS and OS were 5.1 months [95% confidence interval (CI): 4.1-7.7] and 13.3 months (95% CI: 10.1-18.6) respectively. On multivariate analysis ECOG PS ≤ 1 and >2 DEB-TACE procedures were associated with better OS. Patients with ECOG PS ≤ 1 demonstrated a median survival of 17.7 months compared with 5.6 months for patients with ECOG PS > 1 (p = 0.025). Multiple DEB-TACE procedures (>2 procedures) were associated with improved survival (26.8 months) compared with patients with one or two procedures (11.4 months, p = 0.01). Portal vein thrombosis or extrahepatic disease had no statistically significant association with OS.

CONCLUSIONS

DEB-TACE is safe and effective in patients with advanced HCC. ECOG PS ≤ 1 and >2 DEB-TACE procedures were associated with better OS.

Barriers to drug delivery in interventional oncology

Although much attention has been paid to mechanisms of anticancer drug resistance that focus on intracellular processes that protect tumor cells, it has recently become increasingly evident that the unique features of the tumor microenvironment profoundly impact the efficacy of cancer therapies. The properties of this extracellular milieu, including increased interstitial pressure, decreased pH, hypoxia, and abnormal vascularity, result in limited drug efficacy; this finding is true not only for systemic chemotherapy but also for catheter-based therapies, including chemoembolization and radioembolization. The present review summarizes the barriers to drug delivery imposed by the tumor microenvironment and provides methods to overcome these hurdles.

Catheter-directed thrombolysis of arterial thrombosis

Thrombotic or embolic arterial occlusive disease can lead to profound ischemia and, without emergent revascularization, is associated with significant morbidity and mortality. Significant advances in the management of arterial occlusive disease range from newer thrombolytic agents to innovative catheter designs to enhance thrombolysis and thrombectomy. Most of these advances have been directed toward the management of acute limb ischemia; therefore, we review the management of limb ischemia with emphasis on endovascular interventions.

Catheter-directed thrombolysis of deep venous thrombosis

Venous thrombosis is a major public health problem associated with significant morbidity and mortality and has a substantial impact on the quality of life. Over the years, it has become more apparent that anticoagulation alone in the treatment of deep venous thrombosis (DVT) is insufficient in the prevention of postthrombotic syndrome, which adversely impacts the quality of life of the patient, and it is insufficient in preventing recurrence of DVT. With the advent of innovative catheter designs to deliver thrombolytic therapies in the treatment of DVT, there have been significant advances in the management of DVT. We review the management of DVT with emphasis on catheter-directed interventions.

The impact of transvenous cardiac devices on vascular access patency in hemodialysis patients

Creating a vascular access in the presence of a cardiovascular implantable electronic device (CIED) in a patient with or approaching end-stage renal disease can be challenging. In this study, we aimed to evaluate the impact of a CIED on the outcomes of vascular access creation in hemodialysis patients and determine their effects on vascular access patency. This is a single-center retrospective review of hemodialysis patients who underwent vascular access creation after CIED placement. Outcomes of vascular access creation and need for endovascular interventions were compared between patients with vascular access created ipsilateral and contralateral to the site of CIED. Comparing patients with arteriovenous (AV) access created ipsilateral to CIED placement (n=19) versus the contralateral side (n=17), the primary failure rate was 78.9% versus 35.3% (p=0.02). For AV accesses that were matured, the median primary patency durations for AV accesses created ipsilateral to the CIED was 11.2 months compared to 7.8 months for AV accesses created contralateral to the CIED (p=1.00). AV accesses created ipsilateral to a CIED have a higher primary failure rate compared with the contralateral arm and should be avoided as much as possible.

Critical limb ischemia: an update for interventional radiologists

Critical limb ischemia (CLI) is a growing epidemic with bleak patient outcomes. A variety of treatment modalities have been adopted to address CLI based on comorbidities, life expectancy, and the nature of the arterial disease. With advances in technology and treatment strategies, the clinical outcomes of CLI patients have significantly improved over recent years. However, despite progress, patency rates of both surgical and endovascular interventions, limb-salvage and amputation rates are still dismal. We review the epidemiology, treatment strategies, imaging modalities, and the microcirculation aspect of CLI.

Preliminary Experience With Option Inferior Vena Cava Filter

Objectives:

To evaluate the safety and efficacy of Option inferior vena cava (IVC) filter during placement and short-term follow-up.

Methods:

A total of 165 patients (mean age: 60-years) who received Option IVC filter from June 2009 to July 2011 were included. In all, 42 patients presented with deep vein thrombosis (DVT), 26 with pulmonary embolism (PE), and 17 with both. All outcomes were examined until April 30, 2012.

Results:

The filters were successfully deployed in 161patients. During follow-up (mean, 9.5 ± 0.68months), 10 patients were diagnosed with post-filter PE and 13 patients with DVT. There were no instances of fatal PE. Follow-up abdominal computed tomography was available in 60 patients and demonstrated filter-related problems in 8 patients (2: penetration of filter legs, 5:  asymptomatic nonocclusive thrombus, and 1: caval occlusion). There were no instances of filter migration or fracture. In total, 27 filters were successfully retrieved after a mean of 5.27 ± 0.76 months.

Conclusion:

The Option filter was effective and safe during implantation and short-term follow-up and associated with high technical success at retrieval.

Detection of extracellular genomic DNA scaffold in human thrombus: implications for the use of deoxyribonuclease enzymes in thrombolysis

PURPOSE

Mechanisms underlying transition of a thrombus susceptible to tissue plasminogen activator (TPA) fibrinolysis to one that is resistant is unclear. Demonstration of a new possible thrombus scaffold may open new avenues of research in thrombolysis and may provide mechanistic insight into thrombus remodeling.

MATERIALS AND METHODS

Ten human thrombus samples were collected during cases of thrombectomy and open surgical repair of abdominal aortic aneurysms (five samples < 3 d old and five samples > 1 y old). Additionally, an acute murine hindlimb ischemia model was created to evaluate thrombus samples in mice. Human sections were immunostained for the H2A/H2B/DNA complex, myeloperoxidase, fibrinogen, and von Willebrand factor. Mouse sections were immunostained with the H2A antibody. All samples were further evaluated after hematoxylin and eosin and Masson trichrome staining.

RESULTS

An extensive network of extracellular histone/DNA complex was demonstrated in the matrix of human ex vivo thrombus. This network is present throughout the highly cellular acute thrombus. However, in chronic thrombi, detection of the histone/DNA network was predominantly in regions of low collagen content and high cell density, which were mostly near the lumen. These regions of high cell density contained neutrophils and monocytes. Similarly, sections from the acute murine hindlimb ischemia model also exhibited extensive immunoreactivity to the histone antibody in the extracellular space within murine thrombi.

CONCLUSIONS

Extensive detection of genomic DNA associated with histones in the extracellular matrix of human and mouse thrombi suggest the presence of a new thrombus-associated scaffold.

May-Thurner syndrome: can it be diagnosed by a single MR venography study?

PURPOSE

We aimed to evaluate the longitudinal stability of left common iliac vein (LCIV) compression by the right common iliac artery on magnetic resonance venography (MRV).

MATERIALS AND METHODS

This retrospective study included 214 patients diagnosed with May-Thurner syndrome by MRV. We identified a subset of patients who underwent contrast-enhanced cross-sectional imaging of the pelvis six months before or anytime after the MRV and did not undergo any interventional venous procedures between the two studies; 36 patients met these criteria. The degree of venous compression was calculated in both the index and comparison study.

RESULTS

On the index MRV, the mean compression of the LCIV was 62%. However, on the comparison study in the same patients, the mean compression was 39%. The mean change in degree of compression between the two studies was 23% (P < 0.0001), ranging from a 12% increase to 69% decrease in degree of compression on the comparison study.

CONCLUSION

The compressed LCIV on a single MRV study was not stable over time and thus may be insufficient to diagnose May-Thurner syndrome.

Role of preoperative angiography in colon interposition surgery

PURPOSE

The aim of this study was to evaluate the role of preoperative angiography in patients undergoing colonic interposition.

MATERIALS AND METHODS

We searched the electronic database of our radiology department for the term "mesenteric angiography" over a 10-year period from January 1, 2001 to December 31, 2010.

RESULTS

We identified 54 patients who had undergone mesenteric angiography before esophageal reconstruction, 16 of whom proceeded to have colonic interposition surgery. One patient (6.3%) developed graft necrosis, two (12.5%) developed an anastomotic leak, and three (18.8%) developed an anastomotic stricture. These complication rates are similar to those reported in the surgical literature for patients who did or did not undergo routine preoperative angiography.

CONCLUSION

There is no significant difference in the rates of complications secondary to ischemia (graft necrosis, anastomotic stricture, and anastomotic leak) in patients who undergo routine preoperative angiography as compared with those who do not.

Balloon occlusion of the right main bronchus in an ovine model provides sufficient time for emergent interventions in massive pulmonary embolism

PURPOSE

Massive pulmonary embolism (PE) causes hemodynamic compromise and is associated with a high rate of mortality. We sought to create a model of massive PE and to determine whether occlusion of the right main bronchus could mitigate the physiological effects of massive PE in this model.

MATERIALS AND METHODS

We used 27 female sheep to generate a model of massive PE by either autologous blood clot injection (n=18) or detachable balloon release (n=9) into the right main pulmonary artery. Four sheep were excluded after blood clot injection, as they did not exhibit adequate declines in blood oxygen saturation (SaO(2)). Nine of the sheep that received autologous blood clot and nine that received detachable balloons went on to treatment with right main bronchus occlusion. The control group (n=5) received the autologous blood clot, but no occlusion of the right main bronchus. All sheep underwent continuous monitoring of pulmonary arterial mean pressure (PAMP), SaO(2), arterial partial pressure of oxygen (PaO(2)), and arterial partial pressure of carbon dioxide.

RESULTS

Twenty-three sheep (85%) subjected to PE demonstrated immediate tachycardia, tachypnea, and decline in SaO(2) of at least 25% within 30 min. After right main bronchus occlusion, 18 sheep (100%) survived for the length of the experiment and exhibited persistently higher SaO(2) and PaO(2) levels, as well as decreased PAMP compared with the controls. In the control group, two out of five sheep died within 30 min, and the three surviving subjects demonstrated significantly decreased SaO(2) and PaO(2) levels.

CONCLUSION

Occlusion of the right main bronchus in an ovine model of massive PE effectively extends life and provides favorable physiological parameters to allow emergent interventions.

Efficacy of lower-extremity venous thrombolysis in the setting of congenital absence or atresia of the inferior vena cava

PURPOSE

A rare but described risk factor for deep venous thrombosis (DVT), predominantly in the young, is congenital agenesis or atresia of the inferior vena cava (IVC). The optimal management for DVT in this subset of patients is unknown. We evaluated the efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) followed by systemic anticoagulation in the treatment of acute lower-extremity DVT in the setting of congenital IVC agenesis or atresia.

MATERIALS AND METHODS

Between November of 2005 and May of 2010, six patients (three women [average age 21 years]) were referred to our department with acute lower-extremity DVT and subsequently found to have IVC agenesis or atresia on magnetic resonance imaging. A standardized technique for PCDT (the Angiojet Rheolytic Thrombectomy System followed by the EKOS Microsonic Accelerated Thrombolysis System) was used for all subjects. Successful thrombolysis was followed by systemic heparinization with transition to Coumadin or low molecular-weight heparin and compression stockings. Subjects were followed-up at 1, 3, and then every 6 months after the procedure with clinical assessment and bilateral lower-extremity venous ultrasound.

RESULTS

All PCDT procedures were technically successful. No venous stenting or angioplasty was performed. The average thrombolysis time was 28.6 h (range 12-72). Two patients experienced heparin-induced thrombocytopenia, and one patient developed a self-limited knee hemarthrosis, No patients were lost to follow-up. The average length of follow-up was 25.8 ± 20.2 months (range 3.8-54.8). No incidence of recurrent DVT was identified. There were no manifestations of postthrombotic syndrome.

CONCLUSIONS

PCDT followed by systemic anticoagulation and the use of compression stockings appears to be safe and effective in relatively long-term follow-up treatment of patients who present with acute DVT and IVC agenesis or atresia.

Paradoxical embolism after declotting of hemodialysis fistulae/grafts in patients with patent foramen ovale

BACKGROUND AND OBJECTIVES

The safety of percutaneous endovascular declotting procedures for thrombosed hemodialysis fistulae/grafts is well described in the general population; however, its safety in the presence of a patent foramen ovale (PFO) is not known. The objective of this study is to assess the incidence of symptomatic paradoxical embolic events associated with declotting procedure of thrombosed arteriovenous (AV) graft or fistula in patients with documented PFO.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective study in a hospital-based, academic practice. It included 23 patients (10 men; mean age, 65) with PFO and thrombosed hemodialysis graft/fistula who underwent a standardized declotting procedure with 2 mg of Alteplase and balloon thrombectomy. Twenty patients (87%) had AV grafts, and three (13%) had AV fistulae. The PFO shunt was right to left in two (9%), left to right in eight (34%), and bidirectional in ten (44%). The shunt direction was not specified in three patients (13%). The technical success of the declotting procedure and the frequency of clinically manifested paradoxical embolic events in this patient population were calculated.

RESULTS

Fifty declotting procedures were performed on 23 patients with a technical success rate of 96% (48 of 50, 96%). No symptomatic paradoxical embolic events were found in any of the 23 patients with PFO.

CONCLUSIONS

Symptomatic paradoxical embolic events after percutaneous endovascular declotting procedures of thrombosed AV grafts and fistulae in patients with documented PFO are rare. This procedure appears to be safe in patients with a PFO.

Nine-Year Single-Center Experience With Transcatheter Arterial Embolization for Hemoptysis: Medium-Term Outcomes

Purpose: To determine the medium-term efficacy of transcatheter arterial embolization (TAE) for hemoptysis. Materials and Methods: A total of 128 TAE were performed from April 1999 to April 2008 in 58 patients (30:28 F:M) with mean age of 49 (range:16-89). Major causes of hemoptysis included cystic fibrosis/bronchiectasis (24 of 58); lung metastasis (8 of 58); lung cancer (7 of 58); fungal infection (4 of 58). Follow-up was available in 57 of 58 for a median of 1.28 years. Primary and secondary efficacy of TAE for hemoptysis was calculated using Kaplan-Meier estimates. Results: Technical and clinical successes were estimated at 58 (100%) of 58 and 57 (98%) of 58, respectively. Recurrent hemoptysis occurred in 40% (23 of 58). In all, 34% (20 of 58) died during follow-up. Kaplan-Meier estimates for primary and secondary efficacy of TAE at 2, 4, 6, and 8 years were 0.82, 0.46, 0.17, and 0.09 (benign disease) and 0.30, 0, 0, and 0 (malignant disease), respectively. Conclusion: TAE is an effective treatment for hemoptysis in both short- and medium-terms, especially in benign lung disease.

The role of bilateral inferior petrosal sinus sampling in the diagnostic evaluation of Cushing syndrome

Bilateral inferior petrosal sinus sampling is the gold standard diagnostic assay in identifying the pituitary source of adrenocorticotropic hormone secretion in Cushing syndrome. The noninvasive assays used in the workup of Cushing syndrome are often misleading or ambiguous, yielding sensitivities of up to only 80%. Inferior petrosal sinus sampling, however, is highly accurate and safe when performed in experienced centers. We review here the historical and technical details of the procedure, with emphasis on the relevant anatomy and a discussion of possible rare complications.

Angiographic intervention in patients with a suspected visceral artery pseudoaneurysm complicating pancreatitis and pancreatic surgery

OBJECTIVE

To assess the clinical effectiveness of angiography and transcatheter intervention in patients suspected of visceral artery pseudoaneurysm complicating pancreatitis and pancreatic surgery.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

A total of 51 patients who underwent mesenteric angiography for a suspected visceral artery pseudoaneurysm following pancreatitis or pancreatic surgery from 1978 to 2010 were included in this study. There were 39 men and 12 women. The mean age was 66 years (range, 21-89 years) at the time of the angiography. Data on patients' demographics, medical history, angiographic findings, treatment, and outcomes were recorded. Of these 51 patients, 27 had acute pancreatitis, 22 had pancreatic cancer, and 2 experienced pancreatic trauma. Embolization was performed for patients with a pseudoaneurysm. One patient was treated with a stent graft.

MAIN OUTCOME MEASURES

The technical success rate of the intervention, the 24-hour and 30-day rebleeding rates, and the 24-hour and 30-day mortality rates were calculated. A multivariate analysis was performed to determine the factors associated with survival following angiography.

RESULTS

Of the 51 patients studied, 23 had a visceral artery pseudoaneurysm involving the gastroduodenal (7 patients), hepatic (5 patients), splenic (5 patients), and other arteries (7 patients). The technical success rate of the intervention (ie, embolization or exclusion with a Stent graft) was 100%. The 24-hour and 30-day rebleeding rates were 4% and 17%, respectively. The 24-hour and 30-day mortality rates were 0% and 9%, respectively. For the 27 patients who had a negative angiographic finding, the 24-hour and 30-day rebleeding rates were 0% and 11%, respectively, and the 24-hour and 30-day mortality rates were 4% and 21%, respectively. The requirement of a large number of blood products prior to angiography was associated with poor outcome.

CONCLUSION

Embolization was highly effective in treating a pseudoaneurysm complicating pancreatitis and pancreatic surgery. The hemodynamic status at the time of angiography determines overall survival.

Transarterial chemoembolization with Doxorubicin-eluting microspheres for inoperable hepatocellular carcinoma

BACKGROUND

Therapy with drug-eluting microspheres was recently introduced with an aim to decrease the high postoperative morbidity associated with chemoembolization with lipiodol. The purpose of our study was to assess the safety and efficacy of chemoembolization with doxorubicin-eluting microspheres (DEB-TACE) for inoperable hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

In this IRB-approved retrospective study, 54 patients (44 men; median age, 61 years) with inoperable HCC were treated with DEB-TACE. HCC was diagnosed by biopsy in 43 and with a combination of α-fetoprotein (AFP) and imaging in 11. Patients with Child-Pugh A, B, C cirrhosis were 27, 25, 2, respectively. Twenty-one patients had received local therapies prior to DEB-TACE. Tumor was multifocal in 30. Eight patients had branch portal vein thrombosis. DEB-TACE was performed using 300-500μ LC Beads™ mixed with 100 mg of doxorubicin. Twenty-two patients had one DEB-TACE procedure, 23 patients had 2, 8 patients had 3, and 1 had four procedures. Response rate (RR) was assessed using AFP, RECIST, and EASL criteria on CT/MRI at 1 and 3 months. Overall median survival and survival rates at 6, 12, and 24 months were calculated.

RESULTS

DEB-TACE was technically successful in all. Mean hospital stay after the procedure was 1.59 days. Thirty-day mortality was 0%. RR based on AFP was 26%. At 1 and 3 months, CR + PR were 14.8% and 35%, SD 74.1% and 50%, and PD 11.1% and 15%. Overall median survival was 445 days (95% CI 312-590). The survival rates at 6 months, 1 year, and 2 years were 77%, 59%, and 32% respectively.

CONCLUSIONS

Chemoembolization with doxorubicin-eluting microspheres is safe and well tolerated in patients with inoperable HCC. Its efficacy is comparable to the historical controls. However, further prospective studies are required to confirm its efficacy.

TGFβ/activin signaling pathway activation in intimal hyperplasia and atherosclerosis

PURPOSE

Intimal hyperplasia and atherosclerosis are the Achilles' heels of vascular interventions. Many cytokines and growth factors have been shown to mediate these pathological processes. There are conflicting data concerning the expression of transforming growth factor-β1 (TGFβ1) antigen in human intimal hyperplasia and atherosclerotic lesions and conflicting views about whether TGFβ1 is pro- or anti-atherogenic. The presence of TGFβ1 is not sufficient to infer activation of its signaling pathway because TGFβ1 may be present in inactive complexes.

MATERIALS AND METHODS

A sensitive immuno-fluorescence assay (cyanine-3 tyramide signal amplification system) was used on human coronary artery and aorta sections with early or advanced stage lesions to detect TGFβ1, activin, Smad2-P, a marker of the activated TGFβ1/activin pathway and components of latent TGFβ complexes.

RESULTS

All antigens were readily detected in the media and neointima of early stage lesions. The levels were either reduced or undetectable in the media of advanced lesions but were increased in the neointima in areas of high cell density. In marked contrast to activin, TGFβ1 and LAP1 expression levels were closely correlated with Smad2-P throughout the artery wall.

CONCLUSION

Discrepancies in previous data for TGFβ1 expression are probably due to assay sensitivity. TGFβ1, but not activin, expression is consistently correlated with Smad pathway activation in the artery wall. The pattern of Smad2 activation supports a model in which TGFβ/activin signaling is anti-atherogenic in the media of normal artery walls but is equally compatible with an anti-atherogenic or pro-atherogenic response to TGFβ/activin in the neointima of lesions.