Ik Jin Yun

Endovenous Laser Ablation of the Incompetent Small Saphenous Vein with a 980-nm Diode Laser: Our Experience with 3 Years Follow-up

PURPOSE To demonstrate the long-term treatment outcomes of endovenous laser ablation (EVA) of incompetent small saphenous veins (SSV) with a 980-nm diode laser. MATERIALS AND METHODS Eighty-four patients (96 limbs), with varicose veins and reflux in the SSV on duplex ultrasound examination, were treated with a 980-nm diode laser under ultrasound- or fluoroscopy-guidance. Patients were evaluated at 1 week and 1, 3, 6 months, 1 year and yearly thereafter. RESULTS In the 96 limbs, the technical success rate was 100%. The SSV remained closed in 89 of 93 limbs (96%) after 1 month, all of 82 limbs after 6 months, 77 limbs after 1 year, 71 limbs after 2 years and 55 limbs after 3 years. In four limbs where recanalisation was observed, repeat EVA was done resulting in successful obliteration of the SSV. No major complication occurred however bruising (27%), tightness or pain (13%) and paraesthesia (4.2%) were observed. CONCLUSION Endovenous laser ablation with a 980-nm laser wavelength is an easy and safe procedure in incompetent SSVs. After successful treatment, there is a very low rate of recanalisation of the SSV, which suggests that the procedure will provide lasting results.

Moderate-to-severe early-onset hyperuricaemia: a prognostic marker of long-term kidney transplant outcome

BACKGROUND Hyperuricaemia commonly occurs in renal transplant recipients (RTRs), but the effects of post-transplant hyperuricaemia on kidney transplant outcome have not been clearly established. This work was designed to explore the impact of hyperuricaemia on renal transplant outcome. METHODS The authors examined this issue by analysing the clinical outcome of 281 RTRs. Hyperuricaemia (defined as UA > 7.0 mg/dl in men and >6.0 mg/dl in women for at least two consecutive tests, n = 121) was classified as early onset (within 1 year of transplant, n = 90) or late onset (n = 31). Graft function was estimated using the MDRD Study Equation 7 (eGFR(MDRD)). RESULTS As late-onset hyperuricaemia was found to be induced by a progressive decline in the graft function (P < 0.01), data from early-onset hyperuricaemic recipients were used. Early-onset moderate-to-severe hyperuricaemia (defined as UA >or= 8.0 mg/dl) was found to be a significant risk factor for chronic allograft nephropathy (P = 0.035) and a poorer graft survival (P = 0.026) by multivariate analysis, whereas mild hyperuricaemia was not. The impact of moderate-to-severe hyperuricaemia on renal transplant survival was dependent on the duration of exposure. Likewise, the detrimental effect of early-onset hyperuricaemia on the graft function was dependent on UA levels and exposure time. After control of the baseline graft function by analysis of only recipients with a good graft function at 1 year post-transplantation (eGFR(MDRD) > 60 ml/min), moderate-to-severe early-onset hyperuricaemia was also found to be a marker of long-term graft dysfunction and failure. CONCLUSION Moderate-to-severe early-onset hyperuri- caemia may be a prognostic marker of the long-term graft outcome in RTRs, which needs further investigation.

Outcomes of Alpha 1,3-GT-knockout Porcine Heart Transplants Into a Preclinical Nonhuman Primate Model

BACKGROUND Solid organ xenotransplantation is a potential solution to current organ shortages in allotransplantation. We performed four heart transplantations from alpha1, 3-galactosyltransferase gene-knockout (GT-KO) pigs to cynomolgus monkeys and monitored immunological parameters before and after transplantation. METHODS After blood typing of the cynomolgus monkeys, we assessed the binding activity of immunoglobulin G (IgG) and IgM of monkey serum and serum toxicity toward porcine peripheral blood mononuclear cells (PBMCs) using flow cytometry. Immunosuppressive protocols consisted of anti-thymocyte globulin (25 mg/kg), rituximab (20 mg/kg), anti-CD154mAb (20 mg/kg), cobra venom factor (0.05 mg/kg), tacrolimus, and steroid. Cynomolgus monkeys with A or AB blood type with the lowest antibody binding and serum toxicity activity on porcine PBMCs were selected as recipients. RESULTS Absolute numbers of CD3(+) T cells, CD20(+) B cells, and CD3(+)CD95(+) memory T cells in the peripheral blood were suppressed upto 24 days after transplantation. Interferon gamma production of T cells in response to porcine antigens were also significantly suppressed. Heart xenografts from GT-KO pigs survived for upto 24 days without pathologic evidence of rejection. CONCLUSION We successfully performed 4 heart xenotransplantations using GT-KO pigs. We overcame hyperacute rejection by using GT-KO pigs, and all of the heart xenografts from the GT-KO pigs survived between 11 and 24 days without pathologic evidence of rejection, disseminated intravascular coagulation, or consumptive coagulopathy; however, we need to optimize protocols for immune modulation and postoperative care to attain long-term survival of solid organ xenografts.

The Primary Patency and Fracture Rates of Self-Expandable Nitinol Stents Placed in the Popliteal Arteries, Especially in the P2 and P3 Segments, in Korean Patients

Objective We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients. Materials and Methods We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for stenoocclusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were finally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter. Results At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identified in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2; n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent fractures. Just four limbs (up to P2) at the 2-year follow-up did not have stent fracture. The primary patency was 94%, 61% and 44% at 1, 3 and 6 months, respectively, and the group with stent implantation up to P3 had a higher fracture rate than that of the group that underwent stenting up to P2 (p < 0.05). Conclusion We suggest that stent placement up to the popliteal arterial P3 segment and over P2 in an Asian population can worsen the stent patency owing to stent fracture. It may be necessary to develop a stent design and structure for the Asian population that can resist the bending force in the knee joint.

Clinical outcomes of endovascular treatments for critical limb ischemia with chronic total occlusive lesions limited to below-the-knee arteries

Background Diabetes mellitus tends to have the greatest impact on the smaller vessels and contributes significantly to occlusive disease from the popliteal artery distally. Purpose To evaluate the clinical outcomes after a balloon angioplasty with or without stent placement in diabetic patients with critical limb ischemia (CLI) by chronic total occlusion (CTO) limited to below-the-knee (BTK) arteries. Material and Methods From August 2005, patients who presented CLI and CTO limited to the BTK arteries, and who underwent endovascular treatment, were included in this study. The primary endpoints evaluated were technical success, limb salvage, and primary patency. The secondary endpoints evaluated were 30-day access site, intervention site, and systemic complications. Patency and limb salvage were evaluated using the Kaplan-Meier method and compared using Fishers exact test. Results The BTK endovascular treatment (EVT) was performed on 64 limbs. Technical success rate was 93.8% and limb salvage rate was 90.6%. Three of four limbs with technical failure and three of 60 limbs with technical success underwent BTK amputation and the comparison of these rates were significantly different (75% vs. 5%, P = 0.002). Primary patency rates for the limbs were 75% and 59.1% at 6-month and 12-month follow-up, respectively. Minor complications disappeared through the follow-up periods and there was no 30-day complication or systemic adverse events for the treated vessel. Conclusion Even though EVT for CLI in patients with diabetes and CTO in isolated BTK arteries does not have comparable primary patency, it can lead to a very high rate of limb salvage. This result can accentuate the importance of more blood flow to the foot by means of successful revascularization using EVT rather than long-term patency in CTO of isolated BTK arteries.

The 1,470-nm Bare-Fiber Diode Laser Ablation of the Great Saphenous Vein and Small Saphenous Vein at 1-Year Follow-up Using 8-12 W and a Mean Linear Endovenous Energy Density of 72 J/cm

PURPOSE To demonstrate 1-year outcomes after low-energy endovenous laser ablation (EVLA) of incompetent saphenous veins with linear endovenous energy density (LEED) of 80 J/cm or lower with the use of a 1,470-nm diode laser. MATERIALS AND METHODS Incompetent saphenous veins in 236 patients (355 limbs; Clinical/Etiology/Anatomy/Pathophysiology classifications of C2-C4) were treated by EVLA with a bare-tipped 1,470-nm laser with LEED no greater than 80 J/cm (mean, 72.4 J/cm) and laser power of 8-12 W. Patients were evaluated clinically and with duplex ultrasonography at 1 week and 1, 3, 6, and 12 months after EVLA to assess the technical and clinical success and complication rates. RESULTS In the 355 limbs, the technical success rate was 100%. The great saphenous vein (GSV) remained occluded in all 229 limbs (100%) after 1 week, 202 of 203 limbs (99.5%) after 1 month, 157 of 158 limbs after 3 months (99.3%), all 99 limbs after 6 months (100%), and all 41 limbs after 1 year (100%). The small saphenous vein (SSV) remained occluded in all 103 limbs (100%) after 1 week, all 94 limbs (100%) after 1 month, 68 of 69 limbs (98.5%) after 3 months, 40 of 41 limbs (97.5%) after 6 months, and all 14 limbs after 1 year (100%). Two GSVs and two SSVs were recanalized and underwent repeated EVLA. No major complications occurred, although bruising (21% of cases), pain (15%), and paresthesia (4%) were observed. CONCLUSIONS Low-energy EVLA with the use of a 1,470-nm laser with LEED of 80 J/cm or lower is an effective, safe, and technically successful option for the treatment of incompetent saphenous veins.

Fluoroscopy-guided endovenous foam sclerotherapy using a microcatheter in varicose tributaries followed by endovenous laser treatment of incompetent saphenous veins: technical feasibility and early results.

OBJECTIVES To evaluate the technical feasibility and preliminary results of endovenous foam sclerotherapy using a microcatheter in varicose tributaries followed by endovenous laser treatment (EVLT) of incompetent saphenous veins. MATERIALS AND METHODS From July 2005 to August 2006, 312 patients (M:F=139:173, mean age 45.8) who presented with varicose veins with reflux in the saphenofemoral, saphenopopliteal junction or tributaries were enrolled. Under ultrasound or fluoroscopy guidance, selective microcatheterization and endovenous foam slcerotherapy were first performed in varicose tributaries, followed by EVLT (980 nm) of incompetent saphenous veins. Follow‐up at 1‐week and 1‐, 3‐, and 6‐month intervals was done. RESULTS Technical success was seen in 410 of 411 limbs (99%). Continued closure of the saphenous veins and the complete sclerosis of varicose tributaries were noted in 332 of 373 limbs (89%) at the 1‐month follow‐up, all 307 limbs (100%) at the 3‐month follow‐up, and all 274 limbs (100%) at the 6‐month follow‐up. No serious complication was noted. CONCLUSION Endovenous foam sclerotherapy using a microcatheter in varicose tributaries followed by EVLT in incompetent saphenous veins is a safe, effective, and technically feasible treatment for varicose veins. It not only reduces additional sclerotherapy and technical failure, but also makes multiple therapeutic sessions unnecessary. The authors have indicated no significant interest with commercial supporters.

Fluoroscopy-guided endovenous sclerotherapy using a microcatheter prior to endovenous laser ablation: comparison between liquid and foam sclerotherapy for varicose tributaries.

Objective To compare the efficacy and adverse effects of endovenous foam sclerotherapy (EFS) and liquid sclerotherapy (ELS) using a microcatheter for the treatment of varicose tributaries. Materials and Methods From December 2007 to January 2009, patients with venous reflux in the saphenous vein were enrolled. The foam or liquid sclerosant was injected through a microcatheter just before endovenous laser ablation (EVLA). Patients were evaluated for the technical success, clinical success, and procedure-related complications during the procedure and follow-up visits. Results A total of 94 limbs were included: 48 limbs (great saphenous vein [GSV], 35; small saphenous vein [SSV], 13) were managed using EFS and EVLA (foam group; FG), and 46 limbs (GSV, 37; SSV, 9) were treated by ELS and EVLA (liquid group; LG). Varicose tributaries demonstrated complete sclerosis in 92.7% with FG and in 71.8% with LG (p = 0.014). Bruising (78.7% in FG vs. 73.2% in LG, p > 0.05), pain or tenderness (75.6% in FG vs. 51.2% in LG, p = 0.0237) were noted. Hyperpigmentation (51.2% in FG vs. 46.2% in LG, p > 0.05) was found. Conclusion Endovenous foam sclerotherapy using a microcatheter is more effective than ELS for eliminating remnant varicose tributaries prior to EVLA. However, EFS is more commonly associated with local complications such as pain or tenderness than ELS. Furthermore, both techniques seem to prolong the duration of hyperpigmentation along with higher costs.

Early Results of Endovenous Ablation with a 980-nm Diode Laser for an Incompetent Vein of Giacomini

Objective We wanted to evaluate the effectiveness of endovenous ablation of the incompetent vein of Giacomini using a 980-nm diode laser. Materials and Methods A total of 18 patients (18 limbs, 4%) had the incompetent vein of Giacomini. Retrograde reflux originating from the great saphenous vein was noted in sixteen limbs and paradoxical diastolic anterograde reflux from the saphenopopliteal junction was observed in two limbs. After tumescent anesthesia, laser ablation using a 980-nm wavelength laser fiber was performed under ultrasound and/or fluoroscopic guidance. Patients were evaluated clinically and with duplex ultrasound at one week and at one, three, six and twelve months after laser ablation for the technical and clinical success. Results In the 18 limbs, the technical success rate was 100%. Continued closure of the vein of Giacomini was seen in 18 of 18 limbs after one month, in 12 of 12 limbs after three and six months and in six of six limbs after twelve months. No recanalization of the vein and no major complications occurred. Conclusion Endovenous laser ablation with a 980-nm wavelength is an effective and safe procedure for treating an incompetent vein of Giacomini.

Molecular immunology profiles of monkeys following xenografting with the islets and heart of α-1,3-galactosyltransferase knockout pigs.

Effective immunosuppression strategies and genetically modified animals have been used to prevent hyperacute and acute xenograft rejection; however, the underlying mechanisms remain unknown. In this study, we evaluated the expression of a comprehensive set of immune system‐related genes (89 genes, including five housekeeping genes) in the blood of cynomolgus monkeys (~5 yr old) used as graft recipients, before and after the xenografting of the islets and heart from single and double α‐1,3‐galactosyltransferase (GalT) knockout (KO) pigs (<6 weeks old). The immunosuppressive regimen included administration of cobra venom factor, anti‐thymocyte globulin, rituximab, and anti‐CD154 monoclonal antibodies to recipients before and after grafting. Islets were xenografted into the portal vein in type 1 diabetic monkeys, and the heart was xenografted by heterotopic abdominal heart transplantation. Genes from recipient blood were analyzed using RT2 profiler PCR arrays and the web‐based RT2 profiler PCR array software v.3.5. Recipients treated with immunosuppressive agents without grafting showed significant downregulation of CCL5, CCR4, CCR6, CD4, CD40LG, CXCR3, FASLG, CXCR3, FOXP3, GATA3, IGNG, L10, IL23A, TRAF6, MAPK8, MIF, STAT4, TBX21, TLR3, TLR7, and TYK2 and upregulation of IFNGR1; thus, genes involved in protection against viral and bacterial infection were downregulated, confirming the risk of infection. Notably, C3‐level control resulted in xenograft failure within 2 days because of a 7‐ to 11‐fold increase in all xenotransplanted models. Islet grafting using single GalT‐KO pigs resulted in upregulation of CXCL10 and MX1, early inflammation, and acute rejection‐associated signals at 2 days after xenografting. We observed at least 5‐fold upregulation in recipients transplanted with islets grafts from single (MX1) or double (C3, CCR8, IL6, IL13, IRF6, CXCL10, and MX1) GalT‐KO pigs after 77 days; single GalT‐KO incurred early losses owing to immune attacks. Our results suggest that this novel, simple, non‐invasive, and time‐efficient procedure (requiring only 1.5 ml blood) for evaluating graft success, minimizing immune rejection, and blocking infection.