Treatment of chronic hand ischemia is difficult for both the practitioner and patient. The general health condition of these patient is usually relatively poor, especially in those with rheumatic disease. Furthermore, a patient’s desire to pursue active treatments may be low due to the psychosocial distress resulting from the chronicity of the disease. Therefore, surgical treatment options for chronic hand ischemia have rarely been reported in the literature. For this reason, many patients do not undergo active management but only observation. To the best our knowledge, the only recent large series on outcomes of bypass surgery using the saphenous vein in below-the-elbow arterial atherosclerotic occlusive disease was reported by Cheun et al. [22]. In their report, open intervention (bypass surgery) and endovascular intervention showed a high success rate and the incidence of major amputation was decreased.
However, if neglected, chronic hand ischemia can have detrimental effects on a patient’s daily life, occupation, and quality of life. Patients can experience difficulty with hand motion, experience severe pain, and may even need to undergo multiple digit amputations. Therefore, practitioners must offer patient-specific treatments, and, if necessary, active surgical management should be considered.
The authors have investigated proper treatment strategies based on patient discomfort levels and angiographic findings [23]. During this process, we have used various graft sources and have finally concluded that the DIEA is the best graft material for several reasons.
First, long-term patency is the most important factor to consider for grafts. In general, the superior long-term durability and clinical outcomes of arterial grafts compared with those of venous grafts is widely accepted, especially for coronary artery bypass grafting [24, 25]. The excellent long-term patency of the DIEA has been demonstrated [26, 27].
Second, the muscular branches of the DIEA are suitable for various forms of distal anastomoses. Typically, the palmar arch and common digital artery can simultaneously be reconstructed using the Y-shaped graft. Since the proximal portion of the DIEA has a similar diameter to the radial and ulnar arteries, the muscular branches also have similar diameters to the common digital artery, facilitating effective microvascular anastomoses.
Third, venous grafts, such as cephalic or saphenous vein grafts, have been widely used in previous studies [20, 28–30]. In fact, we generally use cephalic vein grafts for short segments of radial artery or digital artery reconstructions as well. However, venous grafts are highly likely to leave long scars in visible areas. In addition, superficial veins have the potential for unknown injuries. However, in DIEA grafts, long grafts can be harvested with only a 5-cm incision on the abdomen, and, if the patient has no surgical history in the abdomen, the artery can be collected easily without trauma.
Fourth, promising histological characteristics of the DIEA have been revealed in previous studies. The DIEA is thinner than more muscular arteries, such as the radial or gastroepiploic arteries, and has a thicker media than does the internal mammary artery. These characteristics allow this type of graft to maintain its strength while being less susceptible to ischemia [31]. In addition, in an ex vivo study, the DIEA showed weak responses to vasoconstrictors, such as noradrenaline, phenylephrine, and serotonin, with strong responses to vasodilators, including acetylcholine, substance P, and bradykinin [32], which can be advantageous for creating a physiologically favorable graft.
It is important to note that there are other sources of arterial grafts, including the thoracodorsal artery and the lateral circumflex femoral artery (LCFA). However, the thoracodorsal artery and its branches have relatively larger diameters than do the palmar arch and the common digital artery. Furthermore, to harvest the LCFA, a long scar is unavoidable. Moreover, the LCFA is susceptible to atherosclerosis and degenerative changes. In contrast, the DIEA is relatively spared from these pathologic changes, suggesting that it is a better arterial graft source. In addition, the DIEA has relatively few anatomical variations. Only the amount of intramuscular portion of the artery varied, which could be solved by intramuscular dissection. Therefore, our first choice was the DIEA, and only if it was impossible, alternative graft sources, such as the thoracodorsal artery or lateral circumflex femora artery, were considered.
Our study also showed that rheumatic disease is a key factor in chronic hand ischemia. Both occurrence and recurrence were closely related to rheumatic disease, as has been reported in a previous study [33]. In the present study, long-term symptom-free rates after DIEA grafts were significantly higher in cases without rheumatic disease, with a 10-year symptom-free rate of 68% in cases with rheumatic disease. We do not think that the patency or the effects of DIEA grafts can be permanently sustained in patients with rheumatic disease, since these grafts are affected by the progression of the systemic disease. However, during the period in which the effect of the surgery is maintained, the patient can return to work and maintain a better quality of life, which are important factors to consider.
The progression rate and severity of the hand ischemia also affected the DIEA graft results. The duration from symptom onset to the operation was significantly longer in the recurred group. A previous sympathectomy, dual radial and ulnar artery grafts, and a concomitant amputation or debridement were significant risk factors for recurrence in the univariate Cox regression analysis. A higher sympathectomy level (including the CPDA and PPDA) and a longer graft length were identified as risk factors for recurrence in the multivariate Cox regression analysis. Although results from the various analyses were not consistent, more severe preoperative conditions had a tendency to be associated with worse results. Therefore, we recommend that an interpositional arterial graft should be performed before an occlusion has progressed to the CPDA level. Timely management is important for avoiding ischemic consequences, including fingertip necrosis and amputation. Therefore, we have applied an algorithmic approach for obtaining a more precise diagnosis and more timely management (Fig. 2) [15].
This study had several limitations. First, given its retrospective design, bias may exist due to inconsistencies in the study population. In this study, no control group that used a vein graft was employed. Our focus is not the superiority of DIEA grafts to vein grafts but the long-term effect of the DIEA graft itself. In addition, the severity, type, and effects of rheumatic disease were not evaluated in detail. Moreover, the criteria for recurrence were not precise and were based on a patient's symptoms rather than a direct evaluation of the patency of the vessel graft itself. Since conventional angiography is an invasive procedure, we did not perform it for routine follow-up but only in select cases who required additional workups (Fig. 3b). In addition, even in patients in whom vessel grafts were occluded due to progression of the underlying disease, the effect of surgery was considered to be maintained if symptomatic improvement was sustained. In our experience, patients with concomitant digital arterial occlusions tend to be more susceptible to symptomatic recurrence. However, this trend was not evaluated objectively. Finally, the number of included cases was relatively small, which limited our ability to perform statistical analyses. This small sample size was related to the rarity of chronic hand ischemia patients. Furthermore, long-term follow-up is not easy in these patients due to aggravation of the systemic disease. However, to the best of our knowledge, there have been no previous long-term follow-up and large-series studies related to interpositional grafting or peripheral arterial bypass grafting in patients with chronic hand ischemia. Further follow-up and analyses based on this study may provide more objective results related to the management of chronic hand ischemia.