A topographical and physiological exploration of C-tactile afferents and their response to menthol and histamine

Unmyelinated tactile (CT) afferents are abundant in arm hairy skin and have been suggested to signal features of social affective touch. Here we recorded from unmyelinated low-threshold mechanosensitive afferents in the peroneal and radial nerves, with the most distal receptive fields located on the proximal phalanx of the third finger for the superficial branch of the radial nerve, and near the lateral malleolus for the peroneal nerve. We found that the physiological properties with regard to conduction velocity and mechanical threshold, as well as their tuning to brush velocity, were similar in CT units across the antebrachial (n=27), radial (n=8) and peroneal nerves (n=4). Moreover, we found that while CT afferents are readily found during microneurography of the arm nerves, they appear to be much more sparse in the lower leg compared to C nociceptors. We continued to explore CT afferents with regard to their chemical sensitivity and found that they could not be activated by topical application to their receptive field of either the cooling agent menthol or the pruritogen histamine. In light of previous studies showing the combined effects that temperature and mechanical stimuli have on these neurons, these findings add to the growing body of research suggesting that CT afferents constitute a unique class of sensory afferents with highly specialized mechanisms for transducing gentle touch.

A propeller superficial transverse cervical artery perforator flap for defect coverage of the submental area: a case report

Reconstruction of submental defects is a challenge that needs to be approached carefully, since many important anatomical structures are located in this small space. Both aesthetic and functional outcomes should be considered during reconstruction. In this report, we describe a case where a superficial branch of the transverse cervical artery (STCA) perforator propeller flap was applied for coverage of the submental area. An 85-year-old woman presented with a 3-cm ovoid mass on her submental area. We covered the large submental defect with a STCA rotational flap in a 180° propeller pattern. The flap survived well without any complications at 1 year of follow-up. A STCA propeller flap is a useful surgical option in reconstruction for defect coverage of the submental area.

Study of contributing arteries to superficial palmar arch formation

The superficial palmar arch (SPA) is formed predominantly by the ulnar artery with a contribution from the superficial palmar branch of the radial artery.: To study contributing arteries in superficial palmar arch formation and variations in its formation.: Study comprised of 30 upper limbs from 15 cadavers. Palmar arches in them were dissected following classical incisions and dissection procedures of Cunninghams’ manual.: SPA was formed by superficial branch of ulnar artery only in 13.33% specimens, by superficial branch of both ulnar and radial artery in 70% specimens, by superficial branch of ulnar and persistent median artery in 13.33% specimens and was formed by superficial branches of ulnar and radial arteries with persistent median artery in 3.33% specimens. SPA was complete in 80% and was incomplete in 20% specimens.: The arch formation is highly variable. Knowledge of contribution to the SPA will be helpful to the reconstructive hand surgical procedures such as arterial repairs, vascular graft applications and re-implantations.

Relationship between the Branching Patterns of the Radial Nerve and Supinator Muscle

The posterior interosseous nerve (PIN) innervates the posterior compartment muscle of the forearm and is a continuation of the deep branch of the radial nerve. The anatomic descriptions of PIN vary among different authors. This study investigated the distribution patterns of PIN and its relationships to the supinator muscle. This study investigated which nerves innervate the posterior compartment muscles of the forearm, the radial nerve, and the PIN, using 28 nonembalmed limbs. Also, the points where the muscle attaches to the bone were investigated. The measured variables in this study were measured from the most prominent point of the lateral epicondyle of the humerus (LEH) to the most distal point of the radius styloid process. For each specimen, the distance between the above two points was assumed to be 100%. The measurement variables were the attachment area of the supinator and branching points from the radial nerve. The attachment points of the supinator to the radius and ulna were 47.9 % ± 3.6 % and 31.5 % ± 5.2 % , respectively, from the LEH. In 67.9% of the specimens, the brachioradialis and extensor carpi radialis longus (ECRL) were innervated by the radial nerve before superficial nerve branching, and the extensor carpi radialis brevis (ECRB) innervated the deep branch of the radial nerve. In 21.4% of the limbs, the nerve innervating the ECRB branched at the same point as the superficial branch of the radial nerve, whereas it branched from the radial nerve in 7.1% of the limbs. In 3.6% of the limbs, the deep branch of the radial nerve branched to innervate the ECRL. PIN was identified as a large branch without divisions in 10.7% and as a deep branch innervating the extensor digitorum in 14.3% of the limbs. The anatomic findings of this study would aid in the diagnosis of PIN syndromes.

Novel Classification of the Branching Patterns of the Superficial Branch and the Deep Branch of the Superficial Circumflex Iliac Artery and the Superficial Inferior Epigastric Artery on Computed Tomographic Angiography

Background Recent advances in the superficial circumflex iliac artery (SCIA) perforator flap transfer emphasized the necessity to comprehensively understand the lower abdominal vasculature. This study aimed to clarify the relationship among the superficial inferior epigastric artery (SIEA), the superficial branch (SCIAs), and the deep branch (SCIAd) of the SCIA. Methods Computed tomographic angiography was retrospectively reviewed in 312 hemiabdomens in 161 female patients who underwent abdominal flap breast reconstruction. We assessed the presence, caliber, and branching patterns of the SCIA branches and the SIEA. Results The SIEA-SCIA common trunk was present in 40.1% of the hemiabdomen and was identified in either side of the abdomen in 63.6% of patients. At least one superficial vessel larger than 1.5 mm was found in 61.5% of hemiabdomens. Seven branching patterns of the SCIA-SIEA system were noted: (1) the SCIA and the SIEA originated together (17.0%); (2) the SIEA and the SCIAs shared an origin (22.8%), (3) the SCIA and the SIEA branched separately (17.0%), (4) each artery originated separately (8.0%); (5) the SCIAs and the SCIAd emerged together with the SIEA absent (17.3%); (6) the SCIAs and the SCIAd originated separately with the SIEA absent (13.1%); (7) the SIEA and SCIAd originated separately with the SCIAs absent (3.5%). Conclusion SCIA-SIEA branching patterns were classified into seven distinctive patterns. This novel classification may help surgeons to choose the optimal pedicle when using the hemi-abdomen region as the donor site.

A topographical and physiological exploration of C-tactile afferents and their response to menthol and histamine.

Numerous microneurography studies in the human peroneal nerve have suggested that CT afferents are lacking in the more distal parts of the limbs. Here we recorded from unmyelinated low-threshold mechanosensitive afferents in the peroneal and radial nerves, with the most distal receptive fields located on the proximal phalanx of the third finger for the superficial branch of the radial nerve, and near the lateral malleolus for the peroneal nerve. We found that the physiological properties with regard to conduction velocity and mechanical threshold, as well as their tuning to brush velocity, were similar in CT units across the antebrachial, radial and peroneal nerves. Moreover, we found that while CT afferents are readily found during microneurography of the arm nerves, they appear to be much more sparse in the lower leg compared to C nociceptors. We continued to explore CT afferents with regard to their chemical sensitivity and found that they could not be activated by topical application to their receptive field of either the cooling agent menthol or the pruritogen histamine. In light of previous studies showing the combined effects that temperature and mechanical stimuli have on these neurons, including a lack of responsiveness to heat, these findings add to the growing body of research suggesting that CT afferents constitute a unique class of sensory afferents with highly specialized mechanisms for transducing gentle touch.

Use of Preoperative High-Resolution Ultrasound System to Facilitate Elevation of the Superficial Circumflex Iliac Artery Perforator Flap

Background During elevation of the superficial circumflex iliac artery (SCIA) perforator (SCIP) flaps, the flap pedicle must often be converted from the superficial branch to the deep branch of the SCIA, complicating and prolonging the procedure. The goal of the present study was to demonstrate the effectiveness of high-resolution ultrasonography to decrease the conversion rate on which no previous report has focused, by making a comparison with a conventional method. Patients and Methods Forty-five consecutive cases where free SCIP flap transfer was performed for reconstruction were retrospectively reviewed. To preoperatively mark the course of the superficial branch, handheld Doppler ultrasonography was used in 27 cases (group 1) and a high-resolution ultrasound system in 18 cases (group 2). Results The conversion rate was significantly greater in group 1 than in group 2 (10/27 [37%] vs. 0/18 [0%], p = 0.003]. The frequency of use of multiple venous anastomoses was significantly higher in group 1 than in group 2 (21/27 [78%] vs. 2/18 [11%], p < 0.001). The operative time was significantly longer in group 1 than in group 2 (p = 0.038). There were no significant differences in postoperative complication rates (1/27 [4%] versus 0/18 [0%], p = 1.0). Conclusion The use of a preoperative high-resolution ultrasound system significantly decreased the rate from of intraoperative conversion from the superficial branch to the deep branch of the SCIA. It also resulted in significantly fewer venous anastomoses and a shorter operative time, while maintaining a low incidence of postoperative complications.