Treatment of Popliteal Artery Aneurysm-Induced Emergencies

Popliteal artery aneurysms (PAAs) represent nearly 70% of all peripheral artery aneurysms. While most PAAs are asymptomatic, symptomatic cases often present with lower extremity ischemia due to acute or chronic thrombosis and distal embolization. Rupture of PAAs and popliteal artery pseudoaneurysms are rare but can lead to life-threatening emergencies. This study focuses on the classification, diagnosis, and management of PAA-induced emergencies, particularly acute hemorrhagic and ischemic complications. These emergencies pose significant challenges, even for experienced vascular surgeons, due to the high risk of limb loss and mortality. Prompt diagnosis and timely intervention are critical to achieving favorable outcomes.

Classification of PAA-Induced Emergencies

PAA-induced emergencies are categorized into two main types: acute hemorrhagic complications and acute ischemic complications. Hemorrhagic complications include ruptured PAAs and pseudoaneurysms, while ischemic complications are primarily caused by acute thrombosis or distal embolization. These emergencies are distinct from uncomplicated PAAs, which are associated with minimal limb loss and perioperative mortality. In contrast, PAA-induced emergencies significantly increase the risk of amputation and death, necessitating urgent and effective management.

Clinical Presentation and Diagnosis

The clinical presentation of PAA-induced emergencies varies depending on the type of complication. Hemorrhagic complications typically manifest as acute pain and swelling behind the knee. In contrast, ischemic complications present with acute rest pain, coolness in the leg or foot, and potential deficits in sensation and motor strength. Due to the rarity of PAAs, non-vascular clinicians may misdiagnose or overlook these conditions, leading to delays in treatment. Misdiagnosis can result in inappropriate therapies, such as thrombectomy for overlooked PAAs or conservative treatment for conditions mistaken as gout or neuropathic pain.

Accurate diagnosis relies on advanced imaging techniques, particularly computed tomography angiography (CTA) and angiography. CTA provides detailed three-dimensional reconstructions and cross-sectional images, which are essential for identifying thrombosed PAAs and assessing the patency of run-off vessels. Cross-sectional images are particularly valuable for detecting aneurysms that may not be visible in three-dimensional reconstructions alone. For patients presenting with acute lower extremity ischemia and popliteal artery occlusion, PAAs should be routinely excluded as a potential cause.

Patient Characteristics and Aneurysm Features

This study included 42 PAAs in 39 patients treated at a major vascular center in China over a 10-year period. Among these, 21 PAA-induced emergencies were managed in 21 patients, including four pseudoaneurysms, two ruptured PAAs, and 15 cases of acute limb ischemia. The cohort consisted of 14 male and seven female patients, with an average age of 59.0 ± 12.8 years (range: 24–82 years). Two patients with acute thrombosis also presented with contralateral PAAs. Baseline characteristics were similar between the hemorrhagic and ischemic groups.

The mean aneurysm size was 4.5 ± 2.1 cm (range: 2.0–10.6 cm). Most patients had solitary saccular or fusiform aneurysms on the main trunk of the popliteal artery, except for one patient with a beadlike aneurysm. In the hemorrhagic group, all three run-off vessels to the ankle were patent. In contrast, at least one vessel was occluded in 12 patients (80%) in the ischemic group, with nearly half (40%) having no patent run-off vessels.

Treatment Strategies

The treatment approach for PAA-induced emergencies was individualized based on the patient’s comorbidities, aneurysm characteristics, type of emergency, and physician preference. Operative details were similar between the hemorrhagic and ischemic groups, except for thrombectomy, which was significantly more common in the ischemic group (0% vs. 60%, P = 0.01). Two patients underwent major amputation without surgical intervention due to bleeding shock with severe infection and irreversible foot ischemia, respectively.

For the remaining 19 patients, endovascular treatment was successfully performed in seven patients (36.8%), while open surgery was used in 12 patients (63.2%). Endovascular procedures, primarily covered stent placement, were exclusively performed in the past five years. In the hemorrhagic group, endovascular therapy with covered stent exclusion was increasingly preferred over open surgery. For acute ischemia, open surgery was the primary approach, with PAAs excluded and bypasses established in 10 patients. Thrombectomy via popliteal artery cutdown was performed in nine patients to improve poor outflow vessels. Endovascular treatment was used in only four ischemic cases, with preoperative thrombolysis performed in one patient to establish a patent run-off vessel.

Outcomes and Follow-Up

The median follow-up time was 50.0 ± 39.3 months (range: 5–119 months). No perioperative or follow-up deaths, aneurysm recurrences, or wound infections were reported. The overall amputation-free survival rates were 85.7%, 85.7%, and 80.9% at 30 days, 1 year, and 3 years, respectively. No significant differences in major amputation-free survival were observed between the hemorrhagic and ischemic groups, with 3-year rates of 83.3% and 80.0%, respectively (P = 0.92). Two limbs required major amputation during follow-up, one due to osteofascial compartment syndrome and the other for radical resection of leiomyosarcoma.

Primary patency rates were 100%, 68.7%, and 60.0% at 30 days, 1 year, and 3 years, respectively, while secondary patency rates were 100%, 85.6%, and 75.0%. No significant differences in graft patency were observed between the hemorrhagic and ischemic groups (P = 0.78 for primary patency, P = 0.41 for secondary patency). In the hemorrhagic group, primary and secondary patency rates were both 75.0% at 1 and 3 years. In the ischemic group, primary patency rates were 66.7% and 54.4%, and secondary patency rates were 88.9% and 75.0% at 1 and 3 years, respectively. Four occlusions in the ischemic group required reintervention, with successful catheter-directed thrombolysis performed in all cases.

Discussion

This study highlights the challenges and outcomes of managing PAA-induced emergencies in a high-volume vascular center in China. The incidence of PAAs in China appears to be lower than in Western countries, but the proportion of emergencies requiring urgent repair is higher. Misdiagnosis and delayed treatment are common due to the rarity of PAAs and the unfamiliarity of non-vascular clinicians with this condition. Accurate diagnosis using advanced imaging techniques, such as CTA, is essential for timely intervention.

The treatment strategy for PAA-induced emergencies should be individualized, considering the patient’s comorbidities, aneurysm characteristics, and type of emergency. Both endovascular and open surgical approaches can achieve satisfactory outcomes, with endovascular therapy increasingly preferred for hemorrhagic complications and open surgery remaining the primary option for acute ischemia. The study demonstrates that with appropriate management, favorable outcomes can be achieved, even in challenging cases of PAA-induced emergencies.

In conclusion, PAA-induced emergencies are rare but life-threatening conditions that require prompt diagnosis and individualized treatment. Advanced imaging techniques and a multidisciplinary approach are essential for achieving favorable outcomes. This study provides valuable insights into the management of these emergencies in a Chinese population, highlighting the importance of early intervention and tailored treatment strategies.

doi.org/10.1097/CM9.0000000000000575

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