The Achilles Tendon Vascular Flow is Achilles’ True Weakness

We present an 82-year-old woman with a history of hypertension who presented as a referral to our center for a non-healing ulcer of the left Achilles area. Two months prior to the onset of the wound, the patient underwent two separate dermatological frozen biopsies proximal to the lesion and of the lesion itself. Initial evaluations found the patient to have chronic venous stasis and treatment with compression stockings and dressings were attempted without resolution. She underwent further treatment of the lesion with antibiotics; however, with no improvement. 

The patient was referred to our center after the wound progressed to exposure of the tendinous segment of the Achilles tendon (Figure 1). Ulcer etiology was hypothesized to be due to the disruption of the arterial bed to the tendon by the dermatologic frozen biopsies. Arterial Doppler ultrasound depicted normal triphasic flow in the femoropopliteal artery and in all three tibial vessels. To further evaluate arterial flow to the ulcer, we advised an arteriogram of the left lower extremity with run-off to the foot.  Digital subtraction arteriogram of the left lower extremity was remarkable for practical absence of vascularity to the ulceration site despite patent popliteal, posterior tibialis, peroneal, and anterior tibialis arteries  (Figure 2).  

The patient has undergone intensive wound therapy including OxyBand (OxyBand™ Technologies) dressing and various levels of immobilization of the Achilles tendon and of left ankle range of motion for several months. This strategy has led to substantial success in wound healing (Figure 3).

Discussion

The Achilles tendon is the thickest and strongest tendon in the human body. It is composed of the adjoining terminal ends of the gastrocnemius, soleus, and the plantaris muscles.¹ The tendon is unique in its anatomical arterial flow, drawing from distinct vascular beds for its vascular supply. The proximal musculotendinous junction and the distal osteotendinous junction of the tendon draw their arterial blood supply from branches of the posterior tibialis artery, whereas the middle tendinous portion of the Achilles is supplied by the fibular/peroneal artery. The mid-portion of the tendon has been reported to have relatively poor vascularization (Figure 4).^2,3  The distal branches of the peroneal artery, which provide blood flow to the mid tendon, are of smaller diameter than the posterior tibialis artery trunk which supplies the arterial flow to the proximal and distal portions of the tendon.  

Wound healing is the interplay between vascular supply and delivery of building blocks for hemostasis, inflammation, proliferation, and wound remodeling/repair.^4,5 This interplay is especially delicate if the wound has multiple vascular beds suppling vital factors for healing. Uniquely, in our case report, the patient’s dermatological freezing served as the noxious insult for local microvascular injury. Peroneal artery microvascular network injury led to severe hypoxemia of the tendinous portion of the Achilles and the development of a deep ulceration which healed after several months of intensive wound care. 

In summary, this case illustrates several clinically relevant points:

1. The different sources of blood flow to the Achilles tendon. The mid-portion or tendinous segment of the tendon is particularly vulnerable to ischemic injury. 

2. The need for careful angiographic evaluation of the Achilles ulcers in the presence of a “normal” noninvasive evaluation. Digital subtraction angiography is required to evaluate the quality of vascular supply to the three portions of the tendon. 

3. Patients with benign skin lesions should be informed of the risk of developing slow or nonhealing wounds with proposed deep cauterization or frozen biopsies, with avoidance of intervention if possible.

Disclosure: The authors report no financial relationships or conflicts of interest regarding the content herein.

Manuscript submitted April 25, 2020, final version accepted April 28, 2020.

Address for correspondence: 

Oscar R. Rosales

orosales@HoustonCardiovascular.com

Author Comments:

Michael Hust, MD, is a Cardiology Fellow at the University of Texas-McGovern School of Medicine, Houston. 

Caroline Fife, MD, is the Director of Wound Care and Hyperbaric Services at St. Luke’s Hospital, Woodlands, Texas.  

Oscar Rosales, MD, is the Director of the Cardiac Catheterization Laboratories at Memorial Hermann Heart and Vascular Institute, and Clinical Professor of Medicine at the University of Texas-McGovern School of Medicine, Houston.

REFERENCES

1. Benjamin M, Theobald P, Suzuki D, Toumi H. The anatomy of the Achilles tendon. In Maffulli N, Almekinders L (eds). The Achilles Tendon. Chapter 2: The anatomy of the Achilles tendon. London: Springer-Verlag. 2007:5-16.

2. Ahmed IM, Lagopoulos M, McConnell P, Soames RW, Sefton GK. Blood supply of the Achilles tendon. J Orthop Res. 1998;16(5):591-596. 

3. Chen TM, Rozen WM, Pan WR, Ashton MW, Richardson MD, Taylor GI: The arterial anatomy of the Achilles tendon: anatomical study and clinical implications. Clin Anat. 2009;22(3):377-385. 

4. Lagergren C, Lindbom A, and Soderberg G. Hypervascularization in chronic inflammation demonstrated by angiography; angiographic, histopathologic, and microangiographic studies. Acta Radiol. 1958;49(6):441-452.

5. Velnar T, Bailey T, Smrkolj V. The wound healing process: an overview of the cellular and molecular mechanisms. J Int Med Res. 2009;37(5):1528-1542.

6. Chen TM, Rozen WM, Pan Wei-Ren, Ashton MW, Richardson MD, Taylor GI. The arterial anatomy of the Achilles tendon: anatomical study and clinical implications. Clin Anat. 2009;22(3):377-385.