Variation of the palmar cutaneous branch of the median nerve identified within the tendon sheath of the flexor carpal radialis

Purpose: During volar plate fixation of distal radius fractures, we have encountered patients with an anomalous course of the palmar cutaneous branch (PCB) of the median nerve within the sheath of the flexor carpi radialis (FCR) tendon. The purpose of this study was to assess the frequency and location of variations of the PCB within the sheath of the FCR tendon.Methods: This retrospective study enrolled 83 patients who underwent volar locking plate fixations through a modified Henry approach for distal radius fractures from July 2018 to April 2020. When we encountered an anomalous PCB within the sheath of the FCR tendon, we documented the specific finding and location where the PCB entered the sheath of the FCR tendon.Results: There were nine patients (10.8%) who had an anomalous course of PCB penetrating the sheath of the FCR tendon. The average entering point of PCB into the sheath of the FCR tendon was 3.07 cm from the distal wrist crease (range, 2.5–3.6 cm).Conclusion: An anomalous course of the PCB entering the sheath of the FCR tendon was observed at a high frequency (10.8%). Care must be taken not to injure the PCB during a dissecting of the FCR sheath during a modified Henry approach for a distal radius fracture.

Efficacy of Modified Thoracoabdominal Nerves Block Through Perichondrial Approach in Open Gynecological Surgery: A Prospective Observational Study and a Cadaveric Evaluation

BACKGROUNDː Modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) was first described as a peripheral nerve block by Tulgar in 2019. This technique provides an analgesic effective range from Th7–11 with a single puncture per side. Although the efficacy and effective duration of M-TAPA have been reported, further examination is required. Therefore, this study aimed to evaluate the analgesic range and effective duration of M-TAPA in open gynecologic surgery.METHODSː Following approval, 10 adult female patients scheduled for open radical hysterectomy via a vertical incision or laparotomy using a midline incision from under the xiphoid process to the symphysis pubis were enrolled. The primary outcome was the number of anesthetized dermatomes at 2 and 24 h postoperatively. Secondary outcomes included numerical rating scale scores and the total amount of fentanyl used. Cadaveric evaluation was performed to assess the spread of the dye. RESULTSː The median numbers (interquartile range) of anesthetized dermatomes at 2 and 24 h postoperatively were 6 (5–7) and 6.5 (5–7) in the anterior cutaneous branch area and 5 (4–7) and 7 (5–7) in the lateral cutaneous branch area, respectively. There was an 85% chance of simultaneously acquiring analgesia in areas innervated by Th8–Th11, including complete block in areas innervated by the anterior cutaneous branches of Th9–10. Cadaveric evaluation showed the spread of the dye in Th8–11.CONCLUSIONSːM-TAPA may have analgesic effects in the areas supplied by the anterior cutaneous branches of Th8–11.TRAIL REGISTRATION:IRB approval (No.2700; registered on July 10, 2020) and registration (UMIN Clinical Trials Registry: UMIN000041137; registered on July 17, 2020)

Clinical application of dorsal digital cutaneous branch flap with partial extensor tendon in repairing compound tissue defects of the dorsal finger

Purpose: To investigate the clinical efficacy of using dorsal digital cutaneous branch flap with partial extensor tendon in repairing compound tissue defects of the dorsal digits of the hand. Methods: Between January 2018 and January 2020, ten patients with skin and soft tissue defects of the digits accompanied by extensor tendon defects underwent surgical repair using dorsal digital cutaneous branch flap with partial extensor tendon. The donor site was repaired with dorsal metacarpal artery flap. The smallest skin defect area was 2.0 × 1.5 cm, while the largest skin defect area was 4.0 × 3.0 cm. The length of tendon defect ranged from 1.5 to 3.0 cm. Sensation within the flap, aesthetic appearance of both the donor and recipient sites, functional recovery, and return-to-work time were measured. Results: All 10 flaps survived after surgery. All patients were followed up for 12–18 months, with an average follow-up period of 15.4 months. After flap repair, the digits had satisfactory shape and appearance along with a soft texture. Hand function was excellent in eight cases and good in two cases. Two-point discrimination was 6–9 mm with an average of 8 mm. No patient experience cold intolerance. The donor sites healed well with satisfactory appearance. Conclusion: Dorsal digital cutaneous branch flap with partial extensor tendon could be used to repair skin and tendon defects simultaneously. The advantages of this method include simple donor tissue harvesting; less donor-site morbidity; reliable blood supply; and satisfactory recovery of appearance, sensation, and function of the flap. Therefore, this method could be suitable for repairing soft tissue defects of the dorsal digits with extensor tendon defects.

Is Palmar Cutaneous Branch of the Median Nerve More Swollen in Carpal Tunnel Syndrome?

Objective To investigate the characteristics of the palmar cutaneous branch of the median nerve (PCBMN) in patient with carpal tunnel syndrome (CTS) using high-resolution ultrasound.Methods Fourteen healthy volunteers (17 wrists) and 31 patients with CTS (41 wrists) were evaluated by high-resolution ultrasound. All patients were classified into three groups based on the electrophysiologic CTS impairment severity: mild, moderate, and severe. Using high-resolution ultrasound, the cross-sectional areas (CSAs) of the PCBMN were measured at the proximal wrist crease, bistyloid line, and distal wrist crease, and the largest CSA was defined as the maximal CSA.Results The maximal CSA of the PCBMN of the control, mild, moderate, and severe CTS groups were 0.27±0.08, 0.30±0.07, 0.35±0.10, and 0.47±0.13 mm2, respectively. The maximal CSA of the PCBMN was significantly larger in the severe CTS group than in the other groups.Conclusion The PCBMN could be concomitantly affected in patients with severe CTS.

Diagnosis and treatment of nerve injury following venipuncture - A report of two cases -

Background: Venipuncture is one of the one of the most commonly performed, minimally-invasive procedures; however, it may lead to peripheral nerve injury. Here, we describe the diagnosis, treatment, and prognosis of two self-reported cases of nerve injury during venipuncture with the aim of drawing attention to possible needle-related nerve injuries.Case: Two anesthesiologists in our hospital experienced an injury of the lateral antebrachial cutaneous branch of the musculocutaneous nerve during venipuncture. Immediately, they underwent ultrasound examinations and nerve blocks with oral medication, resulting in full recovery.Conclusions: Ultrasonography is important for the early and confirmative diagnosis of a nerve injury during venipuncture, and for immediate treatment with a nerve block. Moreover, it is imperative for both the practitioner and the patient to be aware of the possible complication of nerve injury after venipuncture.

The Proximal Fasciocutaneous Hypothenar Flap Based on the Cutaneous Branch of the Deep Palmar Artery: A Case Report

The abductor digiti quinti flap for thumb hypoplasia has been used in its muscular variant as musculocutaneous flap. Several authors have reported myocutaneous branches in the proximal hypothenar region which would vascularize the skin segment covering the hypothenar muscles. Nevertheless, the presence of a cutaneous branch deep palmar artery (CBDPA) vascularizing the proximal hypothenar territory and possibly responsible for the proximal hypothenar cutaneous vascularization was reported. In this paper, a fasciocutaneous hypothenar flap was designed, based on the CBDPA, transposed to the wrist anterior region for the treatment of a post burn contracture which was limiting the wrist extension. Its viability was assessed. The flap had a lozenge-shaped design from the cutaneous fold of the wrist to the fifth metacarpophalangeal joint over the abductor digiti quinti muscle. It was dissected in the fasciocutaneous plane to a width of 20 mm. The adipose tissue zone 10 mm distal to the pisiform was preserved, as well as the ulnar nerve sensory branch crossing the flap longitudinally. The flap was transposed to the anterior fold of the wrist. Neither the flap nor the donor site underwent complications. The patient improved wrist extension without referring any discomfort. Sensitivity was 8 mm 2 months after surgery compared to 6 mm within the preoperative period. In conclusion, it is possible to develop a proximal fasciocutaneous hypothenar flap based on CBDPA involving the proximal and distal hypothenar territory.

Anatomical variations of the innervated radial artery superficial palmar branch flap: A series of 28 clinical cases

Background The innervated radial artery superficial palmar branch (iRASP) flap was designed to provide consistent innervation by the palmar cutaneous branch of the median nerve (PCMN) to a glabrous skin flap. The iRASP flap is used to achieve coverage of diverse volar defects of digits. However, unexpected anatomical variations can affect flap survival and outcomes.Methods Cases in which patients received iRASP flaps since April 1, 2014 were retrospectively investigated by reviewing the operation notes and intraoperative photographs. The injury type, flap dimensions, arterial and neural anatomy, secondary procedures, and complications were evaluated.Results Twenty-eight cases were reviewed, and no flap failures were observed. The observed anatomical variations were the absence of a direct skin perforator, large-diameter radial artery superficial palmar branch (RASP), and the PCMN not being a single branch. Debulking procedures were performed in 16 cases (57.1%) due to flap bulkiness.Conclusions In some cases, an excessively large RASP artery was observed, even when there was no direct skin perforator from the RASP or variation in the PCMN. These findings should facilitate application of the iRASP flap, as well as any surgical procedures that involve potential damage to the PCMN in the inter-thenar crease region. Additional clinical cases will provide further clarification regarding potential anatomical variations.

A Cadaveric Anatomical and Histological Study of Recipient Intercostal Nerve Selection for Sensory Reinnervation in Autologous Breast Reconstruction

Background Autologous breast reconstruction (ABR) has grown in popularity due to improved aesthetic and long-term patient reported outcomes, but data regarding sensory reinnervation of autologous flaps remain limited. Traditionally, the lateral cutaneous branch of the fourth intercostal nerve has been used for flap neurotization, but the use of the anterior cutaneous branch of the intercostal nerves (ACB) offer a more optimal location to the microsurgical field when using internal mammary vessels for the microanastomosis. This study aimed to evaluate the optimum ACB recipient site level for sensory nerve coaptation in ABR. Methods Twelve hemi-chests were dissected from six fresh cadaveric females. Costal cartilages were removed and the anterior cutaneous intercostal nerve (ACB) and the lateral (subcutaneous) division of the anterior cutaneous branch (LACB) of the intercostal nerve were exposed. Anatomical measurements were recorded, and nerve samples were evaluated histologically with carbonic anhydrase staining to differentiate sensory fascicles. Assessment of fascicular diameter, axonal counts, and fascicular area were compared. Results A total of 75 nerve specimens were assessed. The ACB was identified at all levels (100%) and the subcutaneous LACB was noted consistently in the second to fourth rib space (96% cadavers), with a median length of 43, 37.5, and 37 mm, respectively. Across all rib spaces, the fascicular and axonal counts were comparable between the LACB and ACB. Nerves in the second intercostal space had a significantly larger mean fascicular area mean (112,816 ± 157,120 µm2) compared with that in the fourth (mean 26,474 ± 38,626 µm2), p = 0.03. Axonal count of sensory fascicles was the highest in the second intercostal nerves (p < 0.05). Conclusion This study provides anatomical and histological basis to determine the optimum recipient site choice for sensory coaptation in microsurgical breast reconstruction. This would aid in operative decision-making regarding the ideal recipient anterior cutaneous intercostal nerve branches for recipient site coaptation in ABR.

Henry Head’s lifelong studies of cutaneous sensation

In 1900 research on cutaneous sensation was defined by histological techniques defining sensory receptors in skin, leading to undetermined conceptual problems when considered in relation to Brown-Séquard’s startling finding that there were two qualitatively different afferent pathways in the spinal cord. Four modalities were considered to function as the determinants of sensory input. In 1903 Rivers and Head carried out the first interventional study of human cutaneous sensation, and analysed the return of sensation following section and immediate suture of the dorsal cutaneous branch of Head’s left radial nerve. This resulted in the revolutionary idea summarised in his description of protopathic and epicritic sensory systems in peripheral sensory nerve. Although this concept was at best seen as controversial and even ridiculed by some of his many contemporaneous critics, more recently this concept has proven a fundamentally important stimulus to understanding the physiology of cutaneous sensation. His writings show him to have been capable of deeply instructive thought, based on his clinical experience and his admiration of Hughlings Jackson’s teaching concerning the hierarchical organisation of brain function. First and foremost a clinician neuroscientist, his ideas were ahead of their time and not understood.