Address access geometry
A fine fiber and short catheter eliminate the introducer sheath for a segment in which standard access is impractical.
SHEATHLESS ACCESS · SHORT DEEP MUSCLE BRANCHES
UFLAUltrafine laser ablation
A finer approach
to a short-segment challenge.
A 400 μm fiber passes through an 18G catheter without an introducer sheath. One case involving a 1.5 cm deep muscle branch explores access in challenging anatomy.
Chih-Chun Yang, MD · Good Leg ClinicA clinical question. A published study.
01 / THE CLINICAL CHALLENGE
The challenge was the space available for access.
Competent saphenous trunks do not exclude pathological reflux from a deep branch.
What made this case difficult?
A 45-year-old woman presented with leg heaviness, swelling and a popliteal venous aneurysm 26 years after wide resection and radiotherapy for a left-leg rhabdomyosarcoma. Dense fibrosis and scarring in the surgical field complicated access.
Duplex ultrasound showed competent great and small saphenous veins. The reflux source was a deep muscle branch only 1.5 cm long, measuring 2 mm at its origin and dilating to 5 mm near the aneurysm.
This was a case with altered anatomy after cancer treatment. The paper does not establish a causal relationship between the prior surgery and the reflux.
Source: Yang CC. JVS–CIT. 2026;102274. Case report, Technique, Discussion Original article
02 / THE UFLA TECHNIQUE
A finer fiber. An access route without a sheath.
Understand fiber size, access and energy delivery as separate elements.
600 μm → 400 μm
600 μm
Paper comparator400 μm
UFLAAbout one-third smaller in diameter
(600 − 400) ÷ 600 = 33.3%
400 μm = 0.4 mm, or two-thirds of the comparator’s diameter.
The circles are proportional to the reported 600 μm and 400 μm diameters. They are dimensional markers, not device cross-sections showing coatings or tip construction. The comparator 600 μm fiber requires at least a 16G catheter in this report; the 400 μm fiber passes through 18G. Catheter sizes are not assigned the same ratio.
Direct access through an 18G catheter
Under ultrasound guidance, the target branch is cannulated. The metal stylet is removed, leaving a short plastic cannula through which the 400 μm radial fiber passes. “Sheathless” means that the introducer sheath is omitted; a peripheral intravenous catheter is still used.
- Radial fiber
- 400 μm · BA400 R
- Laser system
- 1470 nm · Veincare
- Fiber & system manufacturer
- WONTECH
- Access device
- 18G peripheral IV catheter
The sheathless design addresses the length occupied by an introducer sheath. Stable catheter fixation and clear ultrasound visualization of the fiber tip remain essential.
Confirm position before the next pulse.
UFLA · Sequence schematic, not a heat-spread simulation
The deep muscle branch was treated at 7 W with 1-second pulses and 2-mm pullback increments (stop-and-shoot). Ultrasound verification before each emission was intended to confine delivery to the target segment.
The four positions illustrate sequence only, not the reported total number of pulses, full treatment length, a fixed pause duration or thermal spread. These are this UFLA case’s parameters; SPOT data are not substituted.
Position and stability matter
Smaller access, position checks and tumescent anesthesia have procedural rationale. The report does not compare perforation rates, tissue temperature or nerve-injury rates.
Short-term observations in one case
Duplex ultrasound confirmed target-branch occlusion at three months. The case supports feasibility, without establishing comparative superiority.
Source: Yang CC. JVS–CIT. 2026;102274. Technique, Discussion Original article
03 / OBSERVATIONS & LIMITATIONS
Read the findings within the limits of the evidence.
A single case report, without a control group.
Patient
45-year-old woman · CEAP C3
Follow-up
Clinical and duplex assessment
Total procedure time
Includes superficial procedures
Pain VAS score
Observation in this case
What was observed at three months?
- Duplex ultrasound: complete occlusion of the deep muscle branch.
- Aneurysm thrombosis, with no residual flow.
- Resolution of symptoms, the popliteal bulge and lateral calf varicosities.
- No paresthesia or skin burns were reported.
Source: Yang CC. JVS–CIT. 2026;102274. Results, Limitations Original article
04 / ASSESSMENT & CARE
Identify the source of reflux before choosing the tool.
When might assessment be considered?
Symptomatic reflux from a short deep muscle branch or perforator, especially when sheath deployment is difficult or anatomy has been altered by surgery or trauma. These are potential applications discussed in the report, not broadly validated indications.
What must assessment establish?
Comprehensive duplex imaging must assess truncal competence and establish the target branch as the primary, symptomatic reflux source. The great and small saphenous veins were competent in this case; the finding cannot be generalized to all patients with truncal reflux.
What limits feasibility?
Unstable catheter fixation, excessive shortness or tortuosity, or inability to continuously identify the tip on ultrasound. Limited quartz-fiber flexibility can lead to fracture or vessel injury, with off-target thermal damage or incomplete ablation.
Normal perforators and deep muscle branches should not be treated merely because they are present. Intervention depends on pathological flow, symptoms and the full clinical assessment.
Treatment and follow-up in the reported case
Assess the reflux
Use clinical history, symptoms and duplex ultrasound to identify the responsible short branch and assess stable access.
Local anesthesia & access
In this case, prone positioning and local anesthesia were used. Ultrasound guided 18G catheter access, stylet removal, fiber placement and tumescence.
Verify position & ablate
The branch was treated with 7 W, one-second pulses and 2 mm withdrawal, confirming position each time. Superficial disease received separate laser treatment and phlebectomy.
Clinical & duplex follow-up
The reported three-month visit assessed symptoms and flow. Aftercare, activity and follow-up schedules remain individualized.
Source: Yang CC. JVS–CIT. 2026;102274. Technique, Discussion, Limitations Original article
RESEARCH & PUBLICATION
Every claim leads back to the research.
The sheathless ultrafine laser ablation technique for managing deep muscle branch reflux in hostile anatomy following rhabdomyosarcoma resection
A 400 μm fiber passed directly through an 18G catheter to treat a 1.5 cm refluxing deep muscle branch. Occlusion was confirmed at three months in one patient. Broader applicability and long-term outcomes remain uncertain.
Version of record · August 2026, volume 12, issue 4 · Journal of Vascular Surgery Cases, Innovations and Techniques
DOI: 10.1016/j.jvscit.2026.102274
Original article figures
A and B show the pretreatment appearance; C and D show the three-month follow-up. The report describes resolution of the popliteal bulge and lateral varicosities. Superficial laser treatment and ambulatory phlebectomy were performed in the same session, so the appearance cannot be attributed to deep muscle branch UFLA alone. This is one patient’s outcome.
View full-size figure
A: the refluxing branch connects to the venous aneurysm; THROMBUS denotes clot. B: a 400 μm radial fiber passes directly through an 18G catheter without an introducer sheath. C: the branch appears as a hyperechoic fibrotic cord at three months. D: the aneurysm is thrombosed, with no detectable flow. Original image labels are preserved.
View full-size figureThe BA400 R radial fiber is shown beside a standard 18G peripheral intravenous catheter. The paper reports direct passage through the catheter lumen, eliminating the introducer sheath. This is an equipment photograph, not a manufacturer’s dimensioned engineering drawing.
View full-size figureSource: Yang CC. JVS–CIT. 2026;102274. Figs. 1–3. © 2026 The Author(s). Original article
QUESTIONS & ANSWERS
Questions deserve clear answers.
Understand the principles, suitability and the limits of the evidence.
What is UFLA, and how does it differ from conventional laser ablation?
UFLA stands for ultrafine laser ablation. This paper focuses on sheathless access: a 400 μm fiber passes directly through an 18G peripheral intravenous catheter to reach a short refluxing branch in which a standard introducer sheath cannot be deployed. It is a technical report for a particular anatomical challenge; it does not establish UFLA as the preferred treatment for all varicose veins.
What exactly is about one-third smaller?
The comparison is between the 600 μm and 400 μm fiber diameters described in the paper: (600 − 400) ÷ 600 = 33.3%. The smaller diameter is two-thirds of the comparator. This does not mean a one-third reduction in catheter diameter, puncture size, heat or complications. Gauge numbers such as 18G and 16G cannot be compared as simple percentages.
Does UFLA eliminate thermal or nerve injury?
No. No paresthesia or skin burns occurred in the reported patient, but this was one case with three months of follow-up, without a comparator or temperature measurements. A smaller fiber does not by itself establish lower thermal exposure. The paper emphasizes catheter stability, continuous ultrasound visualization of the tip and tumescent anesthesia. Ablation should not proceed if the tip cannot be identified within the lumen.
What assessment is needed before treatment?
A comprehensive venous duplex ultrasound assessment, medical history and physical examination are central. The clinician must establish truncal vein competence, identify the source of reflux and determine whether the target branch is responsible for symptoms, then assess its length, course, adjacent tissues and suitability for stable catheter access. Deep muscle branches and perforators are normal structures; their presence alone is not an indication for ablation.
Is general anesthesia required? Is the procedure painful?
The reported procedure was performed with the patient prone under local anesthesia, including ultrasound-guided perivenous tumescent anesthesia. The entire procedure took 60 minutes, with a reported visual analog pain score of 1–2. These observations do not guarantee the same anesthetic needs, pain level or procedure duration for another patient.
Can I resume normal activity the same day? Is recovery faster?
The paper does not report time to return to work, normal activity or full recovery, and it does not compare recovery with other treatments. It therefore cannot support a promise of same-day recovery or faster rehabilitation. Activity and aftercare depend on the extent of treatment, any additional procedures and individual clinical advice.
Is follow-up still necessary?
Yes. At three months, clinical review and duplex ultrasound assessed symptoms, appearance, branch occlusion and the absence of residual flow in the aneurysm. Longer-term durability and recurrence remain unknown. Follow-up frequency is individualized; the three-month time point reported in this paper is not a complete follow-up schedule for every patient.
Why is UFLA unsuitable for some patients?
Treatment is considered only for demonstrably incompetent veins responsible for symptoms. A segment that is too short or tortuous, unstable catheter fixation or an inadequately visualized fiber tip may preclude this approach. The paper identifies risks of fiber fracture, vessel injury, off-target thermal damage and incomplete ablation. Choosing UFLA or an alternative requires a complete assessment and discussion.
Are UFLA and SPOT the same technique?
No. This UFLA paper addresses sheathless access to a short deep muscle branch. The SPOT paper focuses on segmental point laser ablation of the below-knee great saphenous vein as a nerve-sparing strategy. They have separate publications and evidence bases. Their data are not interchangeable, and these reports do not establish that the techniques must be used together.
Source: Yang CC. JVS–CIT. 2026;102274. Technique, Results, Limitations Original article
Begin with a complete vascular assessment.
Understand the source of reflux and your individual circumstances before discussing treatment.