Adipofascial Perforator Flaps for Peripheral Nerve Resurfacing after External Neurolysis.

Background: External neurolysis is an important approach to treating symptomatic peripheral nerve entrapment. In cases of recurrent neurolysis or particularly extensive neurolysis, a paucity of overlying soft tissue for closure over the freshly liberated nerve presents a challenge to long-term surgical success as primary closure of this tissue may predispose the patient to recalcitrant epineural scarring. We report the intermediate term outcomes of the use of adipofascial perforator flaps as a means of vascularised tissue resurfacing of nerves in these difficult scenarios. Methods: We retrospectively reviewed patients undergoing external neurolysis for painful peripheral nerve lesions who subsequently had soft tissue reconstruction with local adipofascial flaps. Data with regard to age, gender, limb involved, duration of symptoms, number of prior surgeries, operative time, type of flap, vascular basis of flap, duration of follow-up, visual analogue pain score, monofilament sensory testing and complications were collected. Results: We included six patients (four women) with a minimum follow-up period of 17 months (range: 17-25 months). Age ranged from 39 to 60 years of age. Four cases involved the upper extremity and two the lower extremity. Symptoms had been present between 1 and 10 years. All operations utilised a local adipofascial flap perfused by a named perforating vessel emanating from an adjacent axial vessel. Operative time for flap creation and inset was 74 minutes, on average. There was one minor complication owing to superficial wound dehiscence. All patients reported substantial pain relief (≥five-point reduction on visual analogue scale; scores 0-3 at last follow-up) and objective sensory testing demonstrated improvement. Conclusions: Our report pays particular attention to surgical technique that is applicable to both upper and lower extremities in addition to intermediate term safety and pain outcomes. Level of Evidence: Level IV (Therapeutic).

Use of Vascularized, Denervated Muscle Targets for Prevention and Treatment of Upper-Extremity Neuromas.

Purpose: Neuroma formation following upper-extremity peripheral nerve injury often results in persistent, debilitating neuropathic pain with a limited response to medical management. Vascularized, denervated muscle targets (VDMTs) offer a newly described surgical approach to address this challenging problem. Like targeted muscle reinnervation and regenerative peripheral nerve targets, VDMTs are used to redirect regenerating axons from an injured nerve into denervated muscle to prevent neuroma formation. By providing a vascularized muscle target that is reinnervated via direct neurotization, VDMTs offer some theoretical advantages in comparison with the other contemporary surgical options. In this study, we followed the short-term pain outcomes of patients who underwent VDMT surgery for neuroma prevention or treatment. Methods: We performed a retrospective chart review of 9 patients (2 pediatric and 7 adult) who underwent VDMTs either for symptomatic upper-extremity neuromas or as a prophylactic measure to prevent primary neuroma formation. In-person and/or telephone interviews were conducted to assess their postoperative clinical outcomes, including the visual analog pain scale simple pain score. Results: Of the 9 patients included in this study, 7 underwent VDMT surgery as a prophylactic measure against neuroma formation, and 2 presented with symptomatic neuromas that were treated with VDMTs. The average follow-up was 5.6 ± 4.1 months (range, 0.5-13.2 months). The average postoperative pain score of the 7 adult patients was 1.1 (range, 0-8). Conclusions: This study demonstrated favorable short-term outcomes in a small cohort of patients treated with VDMTs in the upper extremity. Larger, prospective, and comparative studies with validated patient-reported and objective outcome measures and longer-term follow-ups are needed to further evaluate the benefits of VDMTs in upper-extremity neuroma management and prevention. Type of study/level of evidence: Therapeutic III.

Automated 3D ultrasound enables novice users to measure arteriovenous fistula maturation parameters with comparable accuracy to conventional duplex by trained sonographers: Results of a benchtop study.

BACKGROUND: Arteriovenous fistulae (AVF) are considered the preferred hemodialysis access but up to 50% of all AVF created in the United States never mature. Doppler ultrasound (DUS) is useful for predicting fistula maturity and impending fistula failure. DUS is resource-intensive and is associated with poor compliance rates in dialysis patients, ranging from 12% to 33%. METHODS: EchoSure is an FDA-cleared 3D Doppler ultrasound device that automatically delivers quantitative blood flow and anatomic vascular information. The technology can be used at the bedside by personnel without formal sonographic training, nullifying limitations of traditional Duplex ultrasound imaging. This study compared the EchoSure system in the hands of inexpert personnel to a traditional expert-operated DUS for rapid assessment of a benchtop model vascular system with flow, diameter, and depth expected in a human AVF. RESULTS: Both Duplex and EchoSure performed within the expected tolerance of ultrasound readings (35%) for volume flow, with the average error (AE) between the observed measurement and the ground truth being 8% for Duplex and 8% for EchoSure. However, the average coefficient of variation (CV) for Duplex pooled over all flow rate measurements was 17% versus 4% for EchoSure. Regarding diameter, Duplex measurements had AE of 15% with an average CV of 6% across all measurements versus EchoSure AE of 4% and average CV of 2%. Duplex and EchoSure measurements over all depths had the same AE of 2%. The two modalities were not statistically different for depth measurement (p = 0.05) but EchoSure measured closer to the ground truth for flow rate and vessel diameter (flow: p = 0.028, ρ = -0.07; diameter: p < 0.001, ρ = 0.69). The inexpert personnel using EchoSure acquired data 62% faster than the expert sonographers using the Duplex ultrasound (141 min for Duplex vs 87 min for EchoSure). CONCLUSIONS: EchoSure may offer an accurate and convenient alternative for imaging fistulas in the clinic.

Approach to Diagnosis and Treatment of Dorsoradial Hand and Forearm Pain.

Dorsoradial forearm and hand pain was historically considered difficult to treat surgically due to a particular susceptibility of the radial sensory nerve (RSN) to injury and/or compression. A nerve block, if it were done at all, was directed at the region of the anatomic snuff box to block the RSN in an effort to provide diagnostic information as to the pain etiology. Even for patients with pain relief following a diagnostic block, resecting the RSN often proved unsuccessful in fully relieving pain. The solution to successful treatment of this refractory pain problem was the realization that the RSN is not the sole source of sensory innervation to the dorsoradial wrist. In fact, in 75% of people the lateral antebrachial cutaneous nerve (LABCN) dermatome overlaps the RSN with other nerves, such as the dorsal ulnar cutaneous nerve and even the posterior antebrachial cutaneous nerves, occasionally providing sensory innervation to the same area. With this more refined understanding of the cutaneous neuroanatomy of the wrist, the diagnostic nerve block algorithm was expanded to include selective blockage of more than just the RSN. In contemporary practice, identification of the exact nerves responsible for pain signal generation informs surgical decision-making for palliative neurolysis or neurectomy. This approach offers a systematic and repeatable method to inform the diagnosis and treatment of dorsoradial forearm and wrist pain.

Vascularized, Denervated Muscle Targets for Treatment of Symptomatic Neuromas in the Upper Extremity: Description of Operative Technique.

Symptomatic neuromas of the upper extremity often cause persistent, debilitating pain that is resistant to medical management. Following upper extremity amputation, painful neuromas may disrupt rehabilitation efforts and pose a barrier to prosthetic use. Several surgical approaches have been attempted to treat neuromas, each of which suffers from limitations. We have developed a novel technique, the vascularized, denervated muscle target, that offers a compelling new option for primary prevention and secondary treatment of symptomatic neuromas of the upper extremity. Here, we provide a detailed description of our surgical technique as it is applied to neuromas of the upper extremity.

Sensibility, Sensation, and Nerve Regeneration after Reconstructive Genital Surgery: Evolving Concepts in Neurobiology.

BACKGROUND: Sensory recovery following phalloplasty and vaginoplasty for gender dysphoria is essential to the overall success of gender-confirming surgery. Anecdotal evidence suggests that superior reinnervation results are seen in genitoplasty compared to other peripheral nerve repair scenarios. Despite these observed differences, the quality of available literature is poor. METHODS: The authors reviewed the body of English language literature regarding sensory outcomes following genitoplasty for gender confirmation. RESULTS: The available body of literature discussing the basic science and clinical science aspects of sensory recovery following gender-confirming genitoplasty is small. Available data show that sensory recovery following vaginoplasty produces high rates of reported orgasmic ability, largely through the neoclitoris, and a neovagina with vibratory and pressure sensation similar to that of the native vagina. Phalloplasty sensory outcomes are variable, with the largest series reporting return of sensation in the neophallus that is slightly less than what is measured in control men. Erogenous sensation, including the ability to orgasm, is present in nearly all patients after several months. CONCLUSIONS: Existing series indicate that genitoplasty patients experience faster and more complete recovery than any other peripheral nerve regeneration scenarios. However, there are many potential confounding factors in assessment and reporting, and more consistent and reproducible measure endpoints measures are needed. Further research is needed to better understand both the basic science and clinical science of peripheral nerve regeneration in genitoplasty, which may change fundamental aspects of current paradigms of peripheral nerve regeneration.

Upper-Extremity Venous Thromboembolism Following Operative Treatment of Distal Radius Fractures: An Uncommon but Dangerous Complication.

PURPOSE: Distal radius fractures are the most common long bone fracture in the United States, with an estimated incidence of 640,000 cases per year. Operative fixation presents a theoretical risk factor for the development of upper-extremity venous thromboembolism (UE-VTE). Additionally, patients presenting with distal radius fracture commonly have preexisting comorbidities that further increase the risk of UE-VTE. Finally, UE-VTE is considered the highest risk for eventual development of pulmonary embolism. Despite this, scant attention has been paid to studying UE-VTE in this population. The purpose of this study was to measure the incidence of this complication and to identify possible medical factors that increased the risk of developing UE-VTE. METHODS: We queried the Truven MarketScan Commercial Claims and Encounters Database for all patients who experienced a distal radius fracture and were subsequently treated with open reduction and internal fixation between 2012 and 2016. Patients were identified using relevant Common Procedural Terminology codes. Demographic and medical variables were tabulated. Our primary outcome was the development of ipsilateral UE-VTE or pulmonary embolism in the first 60 days after surgery. RESULTS: The study included 24,494 patients. The mean age was 50.7 years (range, 18-91), and 58% were women. There were 79 cases (0.3%) of UE-VTE and 19 cases of pulmonary embolism in the study population (24.1% of all UE-VTE cases; 0.08% of total sample). Multivariable logistic regression showed that coexisting heart failure and estrogen use were associated with increased risk of UE-VTE. CONCLUSIONS: Although uncommon, the development of UE-VTE after open reduction and internal fixation for distal radius fractures is a concerning complication. Coexisting heart failure and estrogen use are associated with increased risk of UE-VTE. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

An Algorithm for the Prevention and Treatment of Pain Complications of the Radial Forearm Free Flap Donor Site.

BACKGROUND: The radial forearm free flap (RFFF) is a staple of microsurgical reconstruction. Significant attention has been paid to donor-site morbidity, particularly vascular and aesthetic consequences. Relatively few authors have discussed peripheral nerve morbidity such as persistent hypoesthesia, hyperesthesia, or allodynia in the hand and wrist or neuroma formation in the wrist and forearm. Here, we present a diagnostic and therapeutic algorithm for painful neurologic complications of the RFFF donor site. MATERIALS AND METHODS: The peripheral nerves that can be involved with the RFFF are reviewed with respect to the manner in which they may be involved in postoperative pain manifestations. A method for prevention and for treatment of each of these possibilities is also presented. RESULTS: Nerves from the forearm that can be harvested with the RFFF will have the most likelihood for injury and these include the lateral antebrachial cutaneous nerve, the radial sensory nerve, and the medial antebrachial cutaneous nerve. A nerve that may be injured at the distal juncture of the skin graft to the forearm is the palmar cutaneous branch of the median nerve. The "prevention" portion of the algorithm suggests that each nerve divided to become a recipient nerve should have its proximal end implanted into a muscle to prevent painful neuroma. The "treatment" portion of the algorithm suggests that if a neuroma does form, it should be resected, not neurolysed, and the proximal portion should be implanted into an adjacent muscle. The diagnostic role of nerve block is emphasized. CONCLUSION: Neurological complications following RFFF can be prevented by an appropriate algorithm as described by devoting attention to the proximal end of recipient nerves. Neurological complications, once present, can be difficult to diagnose accurately. Nerve blocks are critical in this regard and are employed in the treatment algorithm presented.