Clinical Efficacy of Periosteum-Preserving Iliac Crest Transverse Transport for Symptomatic High-Level Lower Extremity Arteriosclerosis Obliterans

Abstract

Lower extremity arteriosclerosis obliterans (LEASO) is a chronic and progressive cardiovascular disease pathologically characterized by intimal thickening, luminal stenosis, and eventual occlusion of arteries supplying the lower limbs, resulting in severe limb ischemia. Its clinical manifestations include intermittent claudication, rest pain, decreased skin temperature, numbness, and pallor. In severe cases, patients may develop non-healing ulcers or tissue gangrene [1]. Patients with its most severe form, chronic limb-threatening ischemia (CLTI), face up to a 25% risk of major amputation within 1 year of diagnosis if timely revascularization is not performed [2].

Our research team has explored and developed an Improved Iliac cortical bone transverse transport (ICTT) technique [3], which incorporates a minimally invasive incision and a periosteum-preserving osteotomy. Herein, we present a study to report the clinical efficacy of ICTT in treating symptomatic LEASO with high-level occlusion at our institution, evaluating its effectiveness in pain relief, wound healing, and improvement of limb perfusion.

We retrospectively analyzed the clinical data of 24 patients with symptomatic high-level LEASO who were treated at our institution between March 2023 and June 2024. This study was approved by the Ethics Committee of Harbin Fifth Hospital (Approval No. HSWYL2023-063), and written informed consent was obtained from all patients.

The inclusion criteria were as follows: (1) A diagnosis of CLTI [4], corresponding to Fontaine Stage III or IV. (2) A confirmed diagnosis of high-level LEASOs via color Doppler ultrasound and computed tomography angiography (CTA). (3) Complete medical and imaging data. Exclusion criteria included: (1) A history of acute stroke or myocardial infarction within 3 months. (2) Severe systemic comorbidities precluding surgery. (3) Active systemic infection or immunosuppressive therapy. (4) Cognitive impairment preventing cooperation.

The final cohort comprised 14 males and 10 females, with a mean age of 64.3 ± 7.2 years. According to the Fontaine classification, 9 patients were Stage III and 15 were stage IV. Preoperative CTA confirmed high-level occlusion of the common femoral or iliac arteries with poor distal runoff in all cases.

All patients underwent a comprehensive preoperative assessment, which included a detailed medical history, physical examination, and routine laboratory tests. The location, severity of arterial occlusion, and the status of collateral circulation were evaluated using color Doppler ultrasound and CTA of the lower extremities. Prophylactic antibiotics were administered routinely, and microcirculation-improving medications were used as deemed appropriate.

The procedure was performed under general anesthesia with the patient in the supine position. An 11-cm incision was made along the outer edge of the iliac crest, beginning at the apex of the anterior superior iliac spine (ASIS) and extending posteriorly. Subcutaneous tissues were sharply dissected down to the extra-periosteal plane. Drill holes were created at 2, 4, 7, and 9 cm posterior to the ASIS apex. Two transport pins were inserted at the 4- and 7-cm marks, and two frame fixation pins were inserted at the 2- and 9-cm marks. Subsequently, two 1-cm incisions were made over the periosteum at 3 and 8 cm posterior to the ASIS. Through these incisions, an osteotome was used to penetrate vertically to a depth of approximately 3 cm. Then, through two additional 1-cm incisions on the lateral aspect of the ilium, the osteotome was used to perform an intracortical transverse osteotomy, creating a “fan-shaped bone flap” (Figure 1). The bone flap was reduced, compression was applied across the osteotomy site, and the external fixator assembly was installed. The wound was thoroughly irrigated, closed in layers, and dressed to complete the surgery.

Postoperatively, all patients underwent continuous and close monitoring of vital signs, blood glucose, and lipid levels at predetermined time intervals. Intravenous antibiotics were administered for infection prophylaxis. Bone transport commenced on the third postoperative day. The protocol consisted of lateral distraction at a rate of 1 mm/day for 14 days, followed by reverse compression back to the original position at the same rate for another 14 days. Patients were encouraged and guided to begin full weight-bearing ambulation with the external fixator under protection on the first postoperative day to promote functional recovery and prevent complications associated with bedrest. The external fixator was typically removed approximately 4 weeks after surgery, once significant clinical improvement and relative stability of the bone regeneration zone were observed.

Rest pain in the affected limb was evaluated using the visual analog scale (VAS), which ranges from 0 (no pain) to 10 (the worst imaginable pain). Scores were recorded 1 day preoperatively, and on postoperative Days 1, 7, 14, and 28. To dynamically assess improvements in distal limb microcirculation, skin temperature on the dorsum of the affected foot was measured at its midpoint. All measurements were conducted by the same trained researcher using a K-type thermocouple thermometer (TES Electrical Electronic Corp.). Prior to each measurement, patients were required to rest in a supine position for at least 30 min in a quiet, temperature-controlled room (22°C), with the affected limb uncovered for acclimatization. For each measurement, the thermometer's probe was placed with gentle but firm pressure directly onto the defined skin site and held in place until the reading stabilized. Three consecutive readings were taken, and their average value was recorded. The timing of these measurements corresponded with VAS assessments. For patients with ischemic ulcers, standardized digital photographs were taken weekly under consistent lighting and from a fixed distance until complete epithelialization was achieved. The time required for complete wound healing was recorded. All complications occurring during the follow-up period, including pin-tract infections, surgical site infections, skin necrosis, secondary fractures at the iliac osteotomy site, and ulcer recurrence, were documented.

All statistical analyses were performed using SPSS software (Version 25.0). All quantitative data were first assessed for normality using the Shapiro-Wilk test. As the data at each time point did not significantly deviate from a normal distribution (all p > 0.05), parametric tests were deemed appropriate. Data are presented as mean ± standard deviation (mean ± SD).

Repeated-measures analysis of variance (ANOVA) was used to compare VAS scores and skin temperature at different time points (1 day preoperatively, and postoperative Days 1, 7, 14, and 28). The assumption of sphericity was checked using Mauchly's test. If sphericity was violated (p < 0.05), the Greenhouse-Geisser correction was applied to adjust the degrees of freedom. When a significant main effect of time was observed, post hoc analysis was conducted using the Bonferroni correction for pairwise comparisons to identify specific differences between time points. A p < 0.05 was considered statistically significant.

All procedures were successfully performed by the same surgical team. The mean operative time was 35.7 ± 5.3 min, and the mean intraoperative blood loss was 51.6 ± 17.1 mL. No major intraoperative or early postoperative complications, such as significant neurovascular injury or iatrogenic iliac fractures, were recorded. All patients completed the follow-up, with a mean follow-up duration of 21.5 ± 4.3 months.

Repeated-measures ANOVA revealed a significant main effect of time on VAS scores (F = 79.93, p < 0.001). The VAS scores for rest pain at 1 day preoperatively and on postoperative Days 1, 7, 14, and 28 were (6.9 ± 1.2), (5.8 ± 1.1), (4.3 ± 1.0), (3.2 ± 0.9), and (2.4 ± 0.8), respectively. Post hoc tests with Bonferroni correction indicated that VAS scores at postoperative Days 7, 14, and 28 were significantly lower than the preoperative baseline (all p < 0.01), establishing a clear trend of pain relief.

Similarly, a significant effect of time was observed for distal limb perfusion (F = 14.44, p < 0.001). The skin temperatures on the dorsum of the affected foot at the same time points were (29.7 ± 1.6) °C, (30.5 ± 1.4) °C, (31.2 ± 1.3) °C, (31.8 ± 1.2) °C, and (32.3 ± 1.1) °C, respectively. Bonferroni-corrected post hoc analysis confirmed that skin temperatures at postoperative Days 7, 14, and 28 were significantly higher than the preoperative measurement (all p < 0.01).

All patients who presented with ischemic ulcers achieved complete wound healing, corresponding to a 100% healing rate. The mean time to complete healing was 15.7 ± 5.1 weeks. During the postoperative follow-up period, no new ulcers or wounds formed. The quality of the healed skin was excellent, demonstrating good texture and elasticity without scar contracture or hyperpigmentation.

Early mobilization was successfully achieved, with all patients performing full weight-bearing ambulation under protection on the first postoperative day. Throughout the follow-up period, no instances of pin-tract infection, deep surgical site infection, or skin necrosis were observed. Radiological evaluations confirmed satisfactory bony union at the iliac osteotomy site in all patients, with no evidence of secondary fractures or adverse bone flap resorption. Furthermore, no ulcer recurrence was noted in any patient during the follow-up period.

Patients with high-level CLTI present a formidable therapeutic challenge due to multilevel arterial disease, often accompanied by microvascular structural damage and dysfunction [5-7]. Although endovascular therapy and open surgical bypass, the current mainstay interventions for LEASO, can partially restore macroscopic blood flow, both have significant limitations. The former demonstrates long-term patency rates of only 40%–60% for long-segment, severely calcified lesions [5], while the latter is associated with a perioperative mortality rate of up to 5%, and is unfeasible in 20%–40% of patients due to the lack of a suitable autologous vein graft [8]. More importantly, neither strategy addresses the microvascular rarefaction and functional impairment caused by chronic ischemia.

Tibial transverse transport (TTT), a technique based on Ilizarov's tension-stress principle, offers a new paradigm for improving microcirculation by inducing angiogenesis via mechanical distraction [9]. However, this technique requires a patent femoropopliteal artery, precluding its use in patients with high-level arterial occlusion. Furthermore, with the osteotomy site on the weight-bearing tibia, it is prone to stress fractures. It is also associated with a high incidence of complications such as pin-tract infections and skin necrosis, and necessitates prolonged restricted weight-bearing, which hinders functional recovery [10].

In the present study, the periosteum-preserving, modified Iliac ICTT technique developed by our team led to a rapid decline in patient VAS scores, a sustained increase in dorsal foot skin temperature, and a 100% healing rate for all ischemic ulcers. These outcomes directly confirm the clinical value of this technique in alleviating rest pain, improving distal perfusion, and promoting tissue repair.

This study has several limitations. First, its retrospective, single-center design and relatively small sample size may limit the generalizability of our findings. Second, the absence of a control group precludes a direct comparison against standard treatments such as endovascular therapy or surgical bypass. Third, the study cohort was assembled from a consecutive, non-randomized series of patients, which may introduce selection bias. Therefore, larger, prospective, multi-center randomized controlled trials are needed to further validate the efficacy and safety of the ICTT technique.

Guangchen Nie: conceptualization, methodology, supervision, funding acquisition, writing. Xiangyue Meng: data curation, formal analysis, writing. Yong Liu, Xuguang Hao, Yang Liu, Shouyang Xiang, Long Jiang, Qiang Xu, and Yicun Lu: clinical investigation, data collection. Yongxin Huo: validation, writing. All authors have read and approved the final manuscript.

This study was approved by the Ethics Committee of Harbin Fifth Hospital (Approval No. HSWYL2023-063). Written informed consent was obtained from all participants or their legal guardians prior to their inclusion in the study.

The authors declare no conflicts of interest.

The data that support the findings of this study are available from the corresponding author upon reasonable request.