Botulinum Toxin as a Treatment for Functional Popliteal Artery Entrapment Syndrome

Contemporary outcomes of surgical decompression for functional popliteal entrapment syndrome

BACKGROUND

Functional popliteal entrapment syndrome (FPES) is an under-recognized source of leg pain caused by dynamic compression of the popliteal vessels by surrounding musculature in the absence of anatomic abnormality. Late recognition and difficulty capturing this entity across imaging modalities can lead to significant morbidity in an often young and active patient population. Surgical outcomes and optimal diagnostic strategies remain uncertain.

METHODS

We performed a retrospective cohort study of all patients undergoing surgical decompression for FPES at an academic medical center between 2018 and 2022. Preoperative symptoms, patient characteristics, imaging, operative details, and follow-up were captured. The primary outcome was symptomatic improvement at last clinic visit. Secondary outcomes included symptomatic improvement at 6 months and postoperative complications.

RESULTS

A total of 24 extremities (16 patients) were included. The mean ± standard deviation age was 23.3 ± 6.4 years and 75.0% of patients were female. The median symptom duration before decompression was 27 months (interquartile range, 10.7-74.6 months). Preoperative symptom severity in the affected extremity was as follows: 33.3% limited from peak exercise, 25% unable to exercise, and 41.7% with debilitating symptoms that affected activities of daily living. Preoperative imaging with provocative maneuvers included duplex ultrasound (87.5%), magnetic resonance angiography (100%), and digital subtraction angiography (100%). Using digital subtraction angiography as the gold standard, the sensitivity for detection of FPES was 85.7% for duplex examination and 58.3% for magnetic resonance angiography. The median follow-up was 451 days (interquartile range, 281-635 days). Most patients demonstrated durable improvement in the affected extremity, with 29.2% realizing complete resolution of symptoms and 37.5% reporting symptomatic improvement at last clinic visit for a total of 66.7%; 20.8% had initial improvement, but developed recurrent symptoms and were found to have elevated compartment pressures consistent with chronic exertional compartment syndrome and were treated with formal fasciotomy. Repeat decompression was required in one extremity (4.2%) owing to recurrent symptoms. Two patients (8.3%) had minimal or no improvement in their affected extremity and workup for the cause of continued discomfort was ongoing.

CONCLUSIONS

Delays in diagnosis of FPES are common. Provocative maneuvers until replication of symptoms across multiple imaging modalities may be necessary to reliably identify the disease process. Surgical decompression improved or completely resolved symptoms in two-thirds of extremities. Treating physicians should maintain suspicion for comorbid chronic exertional compartment syndrome, especially if symptoms recur or persist after decompression.

Novel botulinum neurotoxin-A tibial nerve perineural injection to alleviate overactive bladder symptoms in male rats

Although tibial nerve modulation has shown to induce positive changes in the overactive bladder (OAB), prolonged therapeutic effects using percutaneous stimulation have not yet been achieved. Intradetrusor onabotulinum toxin A injection can provide prolonged therapeutic effects; however, its delivery requires invasive measures. By applying local relief of tibial nerve neural entrapment with onabotulinum toxin A injection, this study investigated the feasibility and efficacy of combining the abovementioned two therapeutic strategies. An OAB animal model was developed using 12 adult Sprague-Dawley rats with cyclophosphamide intraperitoneal injection. A perineural injection site comparable to the tibial nerve perineural injection site and corresponding to that in humans was identified and developed in rats. The toxin was injected five days after establishing the OAB. The incision was made in the skin on the lateral surface of the thigh. The biceps femoris muscle was cut across, exposing the sciatic nerve and its three terminal branches: the sural, common peroneal, and tibial nerves, and 100 units of onabotulinum toxin A was injected into the surrounding tissue. Five days following injection, cystometry was performed. Inter-contraction time, contraction pressure, and interval of the disease state improved with statistical significance. The OAB animal model showed significant improvement with the tibial nerve perineural injection of botulinum toxin, thereby suggesting the possibility of a comparable treatment adaptation in humans.

Functional Popliteal Artery Entrapment Syndrome: An Approach to Diagnosis and Management

Popliteal Artery Entrapment Syndrome (PAES) is an uncommon syndrome that predominantly affects young athletes. Functional PAES is a subtype of PAES without anatomic entrapment of the popliteal artery. Patients with functional PAES tend to be younger and more active than typical PAES patients. A number of differential diagnoses exist, the most common of which is chronic exertional compartment syndrome. There is no consensus regarding choice of investigation for these patients. However, exercise ankle-brachial indices and magnetic resonance imaging are less invasive alternatives to digital subtraction angiography. Patients with typical symptoms that are severe and repetitive should be considered for intervention. Surgical intervention consists of release of the popliteal artery, either via a posterior or medial approach. The Turnipseed procedure involves a medial approach with a concomitant release of the medial gastrocnemius and soleal fascia, the medial tibial attachments of the soleus and excision of the proximal third of the plantaris muscle. Injection of botulinum A toxin under electromyographic guidance has recently shown promise as a diagnostic and/or therapeutic intervention in small case series. This review provides relevant information for the clinician investigating and managing patients with functional PAES.

Functional popliteal artery entrapment syndrome: A review of diagnostic and management approaches

Functional popliteal artery entrapment syndrome (FPAES) presents a challenge for clinicians in the field today. The relative rarity of the disease coupled with its affliction primarily in young, athletic individuals makes it a difficult condition to diagnose. Treatment modalities have been limited to surgical intervention, with more novel methods being developed over the last several years. We present a case report and review the diagnostic and management approaches for FPAES, shedding light on proposed future interventions.

Functional Popliteal Artery Entrapment Syndrome: A Review of Diagnosis and Management

BACKGROUND

Functional popliteal artery entrapment syndrome (FPAES) results from hypertrophied gastrocnemius, soleus, and/or plantaris muscles, without an identifiable anatomic abnormality. Historically, FPAES has been managed with surgical myotomy or myomectomy. Herein, we review the literature to evaluate the results of surgery along with a newer treatment (botulinum toxin A injection) for this rare form of claudication.

METHODS

A literature search in PubMed, Cochrane, and Ovid for studies reporting incidence and management of FPAES yielded 3391 publications; 2804 articles were excluded based on initially established exclusion criteria. Ultimately, data were extracted from six articles, from which the number of patients, demographic information, preoperative workup, surgical treatment details, follow-up imaging, and results of treatment were obtained.

RESULTS

A total of 133 patients were studied. Mean age was 26 years; 57% were female, and noninvasive testing revealed bilateral findings in 39%. Treatment involved surgical myotomy/myomectomy (98; five studies) and botulinum toxin injection (35; two studies). Adjunctive vascular reconstruction was performed in eight of the surgical cases. Patients with FPAES who underwent surgical management were evaluated subjectively for symptomatic improvement, and some patients had duplex ultrasounds in follow-up averaging 25.6 months. Three of 98 patients (3%) had recurrent symptoms, and seven (7%) underwent revision surgical procedures. Complications in the surgical management group included seroma/hematoma (4%, 4/98) and infection (2%, 2/98). For the botulinum toxin treatment group, improvement of symptoms was achieved in 66% of patients at an average follow-up time of ten months. Most patients treated with botulinum toxin did not undergo imaging in follow-up. No complications were reported.

CONCLUSIONS

This review suggests FPAES may be treated successfully with surgical myotomy/myomectomy plus adjunctive vascular reconstruction if necessary. Botulinum toxin A injection may be useful as a diagnostic and therapeutic measure for FPAES.

Popliteal Artery Entrapment Syndrome-Return to Sport Considerations: A Case Report

This is a case of a 19-year-old female collegiate field hockey player with left leg pain, numbness, and tingling. A comprehensive workup including dynamic ultrasound, magnetic resonance imaging (MRI), and magnetic resonance angiogram (MRA) revealed a type VI functional popliteal artery entrapment syndrome (PAES). There are many options for treatment of functional PAES including activity modification, botulinum toxin injection, and surgery. To the authors' knowledge there is no published return to sport recommendation for postsurgical functional PAES. This report highlights alternative treatment options and proposes a postsurgical return to play rehabilitation protocol in functional PAES. LEVEL OF EVIDENCE: V.

Functional popliteal artery entrapment syndrome: use of ultrasound guided Botox injection as a non-surgical treatment option

OBJECTIVE

To determine whether ultrasound-guided injection of botulinum toxin type A (BTX-A) is a viable alternative to surgical intervention for the treatment of functional popliteal artery entrapment syndrome (PAES).

MATERIALS AND METHODS

Twenty-seven patients met diagnostic criteria confirming the presence of functional PAES and agreed to go ahead with ultrasound-guided BTX-A injection at the level of artery occlusion. Patients were assessed and treated at baseline and given the option for 'top-up' injections at 6 and 12 months. Patients provided subjective symptom reports at 6 and 12 months post intervention.

RESULTS

No patients reported being worse off after the intervention; 59% of patients were categorized as having a good response (i.e., initial improvement that was maintained at 12 months), 22% a mixed response (i.e., an initial improvement that subsequently reduced over 12 months) and 19% a poor response (i.e., no difference) to treatment.

CONCLUSIONS

Ultrasound-guided BTX-A injection represents a viable alternative to surgery in the treatment of functional PAES. Further study will help determine the optimum dose and frequency of injection to prevent recurrence of symptoms.