Endovascular and medical therapy of May-Thurner syndrome: Case series and scoping literature review.

INTRODUCTION: May-Thurner syndrome has been recognized as a cause of chronic venous insufficiency and a trigger for venous thromboembolism. There is no consensus about the definition, diagnosis, and therapeutic approach. We are aiming to describe its characteristics and a scoping literature review. METHODS: A retrospective review of patients with May-Thurner syndrome from March 2010 to May 2018 and scoping literature review were made. RESULTS: Seven patients were identified. All patients were female with a median age of 36 (20-60) years. The median time from the first symptom to diagnosis was 3.41 (0.01-9) years. The primary clinical presentation was post-thrombotic syndrome (4 patients). Six patients had at least one risk factor for deep venous thrombosis. All patients underwent angioplasty with stent; patients with acute deep venous thrombosis, furthermore mechanic thrombectomy with or without catheter-directed thrombolysis were done. There were three complications (one patient, lymphedema, and two venous stent thrombosis). Scoping review results were descriptively summarized. CONCLUSION: May-Thurner syndrome has a varied spectrum of clinical presentation, and clinical awareness is paramount for diagnosis. Its principal complication is the post-thrombotic syndrome, which is associated with high morbidity. There is no consensus on the antithrombotic treatment approach.

Rapid assessment of high-dose radiation exposures through scoring of cell-fusion-induced premature chromosome condensation and ring chromosomes.

Analysis of premature chromosome condensation (PCC) mediated by fusion of G0-lymphocytes with mitotic CHO cells in combination with rapid visualization and quantification of rings (PCC-Rf) is proposed as an alternative technique for dose assessment of radiation-exposed individuals. Isolated lymphocytes or whole blood from six individuals were γ-irradiated with 5, 10, 15 and 20Gy at a dose rate of 0.5Gy/min. Following either 8- or 24-h post-exposure incubation of irradiated samples at 37°C, chromosome spreads were prepared by standard PCC cytogenetic procedures. The protocol for PCC fusion proved to be effective at doses as high as 20Gy, enabling the analysis of ring chromosomes and excess PCC fragments. The ring frequencies remained constant during the 8-24-h repair time; the pooled dose relationship between ring frequency (Y) and dose (D) was linear: Y=(0.088±0.005)×D. During the repair time, excess fragments decreased from 0.91 to 0.59 chromatid pieces per Gy, revealing the importance of information about the exact time of exposure for dose assessment on the basis of fragments. Compared with other cytogenetic assays to estimate radiation dose, the PCC-Rf method has the following benefits: a 48-h culture time is not required, allowing a much faster assessment of dose in comparison with conventional scoring of dicentrics and rings in assays for chemically-induced premature chromosome condensation (PCC-Rch), and it allows the analysis of heavily irradiated lymphocytes that are delayed or never reach mitosis, thus avoiding the problem of saturation at high doses. In conclusion, the use of the PCC fusion assay in conjunction with scoring of rings in G0-lymphocytes offers a suitable alternative for fast dose estimation following accidental exposure to high radiation doses.

Holmium: YAG laser-assisted coronary angioplasty with multifiber delivery catheters.

Mid-infrared lasers are attractive for coronary angioplasty based upon their excellent fiberoptic transmission and enhanced tissue absorption. Using a solid-state, mid-infrared holmium:YAG laser with prototype multifiber laser delivery catheters, we performed coronary laser angioplasty with or without adjunctive balloon angioplasty or directional atherectomy in 14 patients with 17 stenoses. Procedural laser success was obtained in 13/14 (93%) patients and 16/17 (94%) lesions; however clinical success was achieved in 9/14 (64%) patients and 12/17 (71%) stenoses. Angiographic restenosis at 4.6 +/- 1.6 months was found in 5/8 (63%) patients. We achieved an excellent procedural laser success rate in patients with generally unfavorable angioplasty anatomy. However, our clinical success rate was not different from that expected with conventional angioplasty alone. The holmium laser remains an attractive energy source for laser angioplasty; but as is the case for all coronary laser systems, its utility as a stand-alone therapy is limited by catheters which create small channels. In this small group, we could demonstrate no clinical benefit for laser-assisted angioplasty in complex coronary lesions. Our results suggest that a randomized trial comparing laser-assisted angioplasty and conventional angioplasty be performed to determine the clinical benefits of this more expensive therapy.

Percutaneous angioscopy of saphenous vein coronary bypass grafts.

OBJECTIVES: We compared the results of percutaneous angioscopy and angiography for detecting critical elements of surface lesion morphology in 21 patients undergoing balloon angioplasty of saphenous vein coronary bypass grafts. BACKGROUND: Angiography remains the standard for diagnosing and treating intravascular pathology associated with atherosclerotic coronary artery disease. It has been demonstrated that coronary angioscopy is more sensitive for identifying more complex atherosclerotic plaques and intracoronary thrombi in native coronary arteries. METHODS: Angioscopy and angiography were performed before and after angioplasty of "culprit lesions" in bypass grafts. All but one of the patients had unstable angina. The mean age of the saphenous vein coronary bypass grafts was 10.1 +/- 2.4 years (range 5 to 15). RESULTS: Restenosis at a prior angioplasty site was present in seven patients. Intravascular thrombi were seen by angioscopy in 15 (71%) of 21 versus 4 (19%) of 21 grafts by angiography (p < 0.001). Dissection was identified by angioscopy in 14 (66%) of 21 versus 2 (9.5%) of 21 grafts by angiography (p < 0.01). The presence of friable plaque lining the lumen surface of the vein graft was detected by angioscopy in 11 (52%) of 21 versus 4 (19%) of 21 grafts by angiography (p < 0.05). There was no correlation between age of the bypass graft and the finding of friable plaque. CONCLUSIONS: We conclude that angioscopy is superior to angiography for detecting complex lesion morphology in bypass grafts and that the presence of friable plaque does not preclude an uncomplicated angioplasty procedure.

Percutaneous coronary angioscopy: applications in interventional cardiology.

We performed percutaneous coronary angioscopy in 35 patients to study the surface morphology of coronary artery lesions. Twenty-five patients had angioscopy performed in conjunction with PTCA, including 20 patients with de novo lesions (16 patients with unstable angina, four patients with stable angina), and five patients with restenosis lesions. Ten cardiac transplant patients had angioscopy performed in conjunction with annual follow-up angiography in attempt to identify accelerated atherosclerotic lesions. There were no complications of angioscopy in any patient. There were no intracoronary thrombi seen either by angiography or angioscopy in the stable angina patients. In the unstable angina group, angiography identified thrombus in 2 out of 16 (12.5%) versus 15 out of 16 (94%) (P less than 0.001) with angioscopy. Following angioplasty, dissections were seen angiographically in 7 out of 16 (44%) of patients versus 16 of 16 (100%) of the patients by angioscopy (P less than 0.01). Restenosis lesions were characterized by a white, fibrous appearance instead of the usual yellow color of primary atherosclerotic lesions. In the ten cardiac transplant patients, angioscopy appeared to be more sensitive than angiography for the detection of atherosclerosis. Yellow (atherosclerotic) and white (fibrotic) plaques were seen in the transplant patients, which often were not detected by angiography. In summary, angioscopy is an excellent tool for visualizing the surface morphology of coronary artery lesions. The clinical indications for angioscopy remain undefined at present.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambiguous coronary angiography: clinical utility of intravascular ultrasound.

We report the use of intravascular ultrasound (IVUS) in situations where angiography was ambiguous or uncertain in assessing the significance of coronary stenoses. The indications for performing intravascular ultrasound were 1) angiographic findings did not correlate with the clinical presentation (n = 5) and 2) the lesion was not seen well by angiography because of overlapping vessels at the site of suspected stenosis (n = 3). We studied eight lesions in seven patients. Six nonobstructive stenoses on angiography were shown by IVUS to be significant. In two patients, stenoses were thought to be significant on angiography, but, due to overlapping of the vessels, there was doubt regarding the severity of the narrowing. In these two patients, IVUS clearly showed that the lesions were nonobstructive. As seen from the above results, angiography underestimated 6/8 stenoses and overestimated in 2/8 stenoses when compared to IVUS. We conclude that IVUS can be used to clarify ambiguous angiographic findings which can have a major impact on the clinical decision making.

A new balloon-expandable tantalum coil stent: angiographic patency and histologic findings in an atherogenic swine model.

The angiographic patency and histologic characteristics of a new balloon-expandable tantalum stent were studied after implantation intervals ranging from 1 to 32 weeks in atherogenic miniature swine peripheral and coronary arteries. Stents were placed in 34 arteries (10 coronary and 24 iliac arteries) in a total of 13 swine. Two swine died within 24 h of stent implantation. Follow-up angiography was performed before death was induced in 11 swine (8 coronary and 19 iliac arteries) and revealed 100% patency without evidence of lumen stenosis, thrombosis or migration of the stents. The neointimal thickening was maximal at 4 weeks after stent implantation and was at its minimum at 32 weeks after implantation with reendothelialization of the stents generally complete at that time. An advantage of this balloon-expandable device is its inherent longitudinal flexibility. The coil configuration allowed the nondeployed stent to negotiate acute bends in coronary arteries to reach the site of implantation and also allowed the deployed stent to conform to the natural contour of tortuous coronary arteries. The tantalum device was remarkable for its radiographic visibility, which greatly aided its placement under fluoroscopic guidance. This study demonstrates this stent's ease of implantation, excellent patency rate and absence of restenosis due to neointimal proliferation for up to 8 months in this atherogenic swine model.

Percutaneous coronary angioscopy in patients with restenosis after coronary angioplasty.

Percutaneous transluminal coronary angioscopy with a flexible steerable microangioscope was performed in five patients undergoing repeat angioplasty. Recurrent lesions were assessed by angioscopy before and after the angioplasty procedure. The most common surface morphology observed in these restenosis lesions was that of white unpigmented lesions consistent with the proliferation of fibrous tissue. Also noted during angioscopy was the presence or absence of thrombus or dissection in association with the lesions either before or after angioplasty. Filmy wisps of tissue, presumably intimal flaps, were commonly visualized after angioplasty. There were no complications related to angioscopy or angioplasty in these patients. The surface morphology of restenosis lesions appears to be different from that of primary atherosclerotic lesions. The lesions in these five patients with restenosis were generally white and fibrotic in appearance, as opposed to the pigmented yellow to yellow-brown lesions commonly seen in undilated atherosclerotic lesions. It was also noted that the presence of intracoronary thrombus was strongly associated with the clinical syndrome of unstable angina. These findings support the hypothesis that restenosis lesions are the result of a reparative process consisting of smooth muscle cell proliferation and fibrosis.

Percutaneous angioscopy during coronary angioplasty using a steerable microangioscope.

The feasibility of using a flexible, steerable angioscope to perform coronary angioscopy before and after percutaneous coronary angioplasty was tested. The microangioscope fits through an 8F coronary angioplasty guiding catheter and contains a multifiber viewing bundle incorporated into the body of a 4.3F balloon catheter with a central lumen for distal flushing and guide-wire passage. Angioscopy was performed without complications 45 times in 24 patients, including 6 patients with stable and 18 with unstable angina. Circumferential visualization of the target lesion was successful in 20 (83%) of the 24 patients and improved with operator experience. Excellent visualization of the target lesion was achieved in 16 (94%) of the last 17 patients. Plaque, thrombus and dissection were among the abnormal findings in the 20 patients (4 with stable, 16 with unstable angina) in whom circumferential viewing of the target lesion was achieved. In four patients with restenosis after angioplasty, the lesion morphology was distinctly different from that of lesions in arteries without prior angioplasty. In patients with stable angina, no thrombus or dissection was seen by angiography or angioscopy before angioplasty. In patients with unstable angina, thrombus was detected more frequently by angioscopy than by angiography before angioplasty (8 versus 2 of 16) and after (15 versus 2 of 16) angioplasty. Intimal dissection was also seen much more frequently by angioscopy than by angiography before angioplasty (7 versus 0 of 16) and after angioplasty (16 versus 7 of 16). It is concluded that high resolution percutaneous coronary angioscopy can be performed safely in conjunction with balloon angioplasty. Further investigation is needed before this diagnostic tool can be applied clinically.

Recanalization of arterial occlusions with a lensed fiber and a holmium:YAG laser.

Laser recanalization of totally occluded swine iliac arteries was performed to assess the safety and efficacy of a lensed fiber laser angioplasty system with a holmium:YAG (2.1 microns) laser. Silica lenses of 1.0 mm, 1.3 mm, and 1.5 mm in diameter attached to the distal end of a 300-microns diameter silica fiber delivered fluences of 79.5 J/cm2, 31.4 J/cm2, and 25.5 J/cm2, respectively. The pulse duration of the laser was 250 microseconds and the repetition rate was 4 Hz. The mean length of the total occlusions was 5.3 +/- 2.0 cm (range 0.5 cm to 8.0 cm). Successful recanalization was obtained in 16/16 lesions without angiographic vessel perforation. Angiographically significant residual stenoses (greater than 50%) remained in every case following successful laser recanalization. Histologically there was minimal evidence of thermal or acoustic tissue injury; however, in 4 of 16 arteries there was evidence of deep arterial dissection following laser recanalization. We conclude that this lensed fiber coupled with a holmium:YAG laser is a safe and effective method for crossing total occlusions in the relatively straight iliac arteries of this animal model.