A 42-year-old woman presents with severe ischemia to bilateral hands. She has had a long-standing diagnosis of Raynaud’s disease with no diagnosis of an autoimmune disorder. She previously had proximal sympathectomies as well as palmer and digital sympathectomies. The progressive ischemia resulted in amputation of the thumb, index, and long finger (▶Fig. 18.1). Her current presentation involves severe ischemia to all fingers of the right hand as well as the remaining digits on the left hand. She was extremely worried about losing the remaining fingers on the left hand as well as digits on the right as this was her primary hand for daily activities. Proximal sympathetic blocks did not work and the discussion with the patient hinged around repeat palmer and digital sympathectomy or Botox (or onabotulinumtoxinA) injections.
Raynaud’s phenomenon is a painful vasospastic condition of the digits usually induced by stress or exposure to the cold. The vasospasm produces a characteristic triphasic color change in the hands that begins with pallor, cyanosis, and finally hyperemia. If prolonged, arterial vasospasm can lead to digital ischemia resulting in ulcerations and gangrene.
While the definitive etiology for Raynaud’s phenomenon has yet to be elucidated, several theories have been proposed. The majority of the theories are centered around a dysfunctional local sympathetic nervous system. However, other studies implicate abnormal platelet function or red blood cell morphology or dysregulation of neuropeptides.
Initial treatment of Raynaud’s phenomenon is nonoperative and characterized by behavior modifications including smoking cessation and reducing cold exposure and stress. In addition to lifestyle changes, pharmacologic agents directed at altering the abnormal arterial vascular response seen in Raynaud’s phenomenon are the primary mainstay for treatment. Calcium channel blockers are utilized most commonly; however, phosphodiesterase-5 inhibitors and endothelin antagonists are also frequently used. If a patient fails conservative management, additional interventions should be considered.
Cervical dorsal sympathectomy, digital sympathectomy, and arterial bypass grafting are all accepted surgical techniques to treat refractory Raynaud’s phenomenon. However, these interventions can be associated with significant morbidity and have varying results.
There continues to be much debate regarding the location and extent of dissection for digital sympathectomies. Proximal, or thoracic, sympathectomy has fallen out of favor by most due to the disappointing long-term results. Sympathectomy is most effective if performed closer to the location of symptoms, with a more extensive palmar dissection to improve long-term outcomes. Extended periarterial sympathectomy, which includes the adventitia of the ulnar artery, superficial arch, common digital vessels past their bifurcation, along with the radial artery as it courses dorsally, improves ischemic pain in 95% of patients and will allow digital ulcers to completely heal in almost 80% of cases.
However, surgical sympathectomy may not result in long-term improvement as well. Also, some patients may be unwilling to undergo surgery. Botox injections are an excellent option in these situations. While the exact mechanism of action for botulinum toxin has yet to be clarified, a number of clinical studies have demonstrated excellent results. Botox may work by blocking ectopic sodium channels or specific chronic pain receptors such as transient receptor potential vanilloid 1 (TRPV-1) or it may work through the sympathetic blockade or even through modulation of neurotransmitters such as substance P, calcitonin gene–related peptide, norepinephrine, and glutamate.