Should You Explore the Brachial Artery in Children Who Have a Perfused Hand but No Palpable Radial Pulse After Sustaining a Supracondylar Humeral Fracture?

Abstract

Commentary The articles by Weller et al. and Scannell et al. add another seventy patients to the literature describing good outcomes for closely observed patients who have a perfused hand but no palpable radial pulse after undergoing closed reduction and percutaneous pinning of a supracondylar humeral fracture. Weller et al. described a high-volume experience at their institution, where the approach is to observe most patients who have a perfused hand but no palpable pulse in association with a supracondylar humeral fracture (this approach varies according to the preference of the attending surgeon, however, so some of these fractures were explored during the time course of the study). If a palpable radial pulse does not return following closed reduction and percutaneous pinning, the rationale for exploration of the brachial artery in their center hinges on the outcome of Doppler assessment of the radial artery; that is, vascular consultation and exploration for those without a Doppler signal, and observation for those who have a Doppler signal. Their paper has the limitations of a retrospective study, and they do not have very long follow-up on the patients. They do report on the cases of two patients that provide valuable teaching points. One patient, who had improved vascular status after undergoing closed reduction and percutaneous pinning, had subsequent deterioration during observation and was returned to the operating room for exploration after developing a cool, poorly perfused hand. Another patient with a perfused hand but no palpable radial pulse developed an ischemic contracture of the forearm despite having a benign and routine postoperative hospital course. This patient had no palpable pulse before or after closed reduction and percutaneous pinning but had a Doppler signal at the radial artery before and after and had a palpable pulse prior to discharge from the hospital. After discharge, the patient had a visit to an outside emergency department (records of this encounter were not available), and then later presented to the orthopaedic clinic with skin loss and signs of an ischemic contracture. The time course for this patient suggests late development of arterial occlusion and/or compartment syndrome, and it is difficult to determine how valuable brachial artery exploration at the time of closed reduction and percutaneous pinning would be in a patient who shortly after that had a normal neurological examination and a palpable radial pulse prior to discharge. The authors recommend that patients who have a perfused limb but no palpable radial pulse after closed reduction and percutaneous pinning of a supracondylar humeral fracture be observed for twenty-four to forty-eight hours—this is a clinically reasonable and often stated recommendation—but there are little data to support a specific time period for observation in their paper or in the literature. The late Mercer Rang advised in his classic textbook, Children’s Fractures, that “the main consideration” when taking care of children who have a perfused hand but no palpable radial pulse in association with a supracondylar humeral fracture is to “avoid catastrophe.”1 He did not advise exploration of the artery if the pulse was not palpable but the hand was well perfused2. The institutional approach described in the paper by Scannell et al. follows this advice and has been associated with excellent intermediate-term functional results and no permanent neurological deficits or ischemic contractures following observation of patients with a perfused hand but no palpable radial pulse after supracondylar humeral fracture. Assessment included an outcomes questionnaire, functional testing, assessment of arm and forearm length and girth, and a duplex vascular assessment. Results and recommendations are in line with the Children’s Hospital Los Angeles experience described in January 2010 by Choi et al.3, although their follow-up and the vascular status and functional evaluation of patients was limited. Some key observations from the paper by Scannell et al. are that well perfused means that the hand on the injured side has the same color, capillary refill, and temperature as the hand on the uninjured side, the fracture reduction should not have a “gap” at the fracture site, patients should be observed carefully with frequent checks of neurological and vascular status, and patients should not have any progressive neurological deficits, increasing distal swelling, or a change in the perfusion status. Scannell et al. reports that children who are managed expectantly and do not show the warning signs of ischemia in the early postoperative phase (twenty-four to thirty-six hours) have a return of a palpable radial pulse and go on to have excellent functional outcomes. A few patients developed osteonecrosis of the trochlea, and thus perhaps patients with a perfused hand but no palpable radial pulse in association with a supracondylar humeral fracture should be followed longer and might benefit from repeat radiographs at six to twelve months after injury. Five of the twenty patients had an occluded brachial artery at the time of final follow-up. Return of a palpable radial pulse after closed reduction and percutaneous pinning was predictive of a patent brachial artery at the time of follow-up. The presence or absence of a Doppler signal after closed reduction and percutaneous pinning was not predictive. The presence of a complete median nerve palsy was predictive of brachial artery occlusion at the time of final follow-up, and a recent report by Mangat et al.4 has also recommended anterior interosseous or complete median nerve palsy as an indication for brachial artery exploration. Anterior interosseous nerve palsy alone was not predictive of occlusion in the paper by Scannell et al. It is not known if arterial exploration in these patients would have improved their clinical outcomes, as the nerve palsies all resolved and the patients did not have functional vascular problems. Benedetti Valentini et al.5 recently reported on a small series of children who had vascular compromise as a result of supracondylar humeral fracture and who underwent ultrasound evaluation of brachial artery patency and distal pressures before undergoing closed reduction and percutaneous pinning. The authors of that study reported that these noninvasive techniques were quick and reliable and that, in four of their patients who had a perfused hand but no palpable radial pulse and in whom a brachial artery injury had been identified with use of ultrasound, the brachial artery was found to be patent at the time of exploration and release (three patients) or repair (one patient) and the patients had no functional problems. In a published survey and meta-analysis study, White et al.6 made the following points, which are based on their extensive review of the literature: (1) absence of a pulse after supracondylar humeral fracture is a strong indicator of arterial injury, (2) collateral circulation about the elbow can be variable and unreliable, and (3) brachial artery revascularization in children can be done successfully and has been associated with high patency rates. They advocated for increased utilization of intraoperative color flow Doppler ultrasound following reduction and pinning if the pulse does not return. So, how should you handle a supracondylar humeral fracture in a child who has a perfused hand but no palpable radial pulse? Be prepared for the possibility of being called to treat a child who presents with a supracondylar humeral fracture and vascular compromise—consider the possible scenarios and how you will handle them, review these recent studies, and discuss a treatment approach with your vascular surgery colleagues. The studies by Weller et al. and Scannell et al. provide further support that careful observation of a patient who has a well-perfused hand but no palpable radial pulse in association with a supracondylar humeral fracture will result in return of the radial pulse and normal clinical function except in rare cases, and even in some children who were subsequently found to have an occluded brachial artery. The challenge is to identify and not miss the rare case; however, exploration of the brachial artery is not without risks, and patients managed this way may also subsequently sustain functional deficits. Evaluation for the presence of a Doppler signal in the radial artery at the wrist is an additional test utilized by Weller et al. before proceeding with inpatient monitoring and observation. Patients with deterioration of distal perfusion or neurological function or with signs of compartment syndrome should be urgently evaluated and treated. Although approximately 5% to 10% of children with a supracondylar humeral fracture may present with vascular impairment, a prospective study to compare observation with exploration likely cannot be done ethically and with enough power to sort out the confounding variables with regard to patient presentation and treatment options. In centers that have ultrasound imaging capabilities to evaluate the brachial artery with color-coded duplex scanning and ultrasound velocimetry, protocols to apply this diagnostic technology to children with perfused pulseless supracondylar humeral fracture may add information that assists in clinical decision-making. Following either closed reduction and percutaneous pinning with subsequent observation or exploration and pinning, patients with these injuries should be carefully monitored postoperatively for twenty-four to forty-eight hours for signs of deterioration, and parents or guardians of these children should be instructed at the time of discharge to return the child urgently (and to the same center, when possible) for evaluation if warning signs of ischemia or swelling appear after discharge, in order to “avoid catastrophe.”