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An 89-year-old Caucasian male cadaver with prostate cancer demonstrated bilateral persistence of the median artery and bifid median nerve (BMN) during upper limb dissection. The persistent median artery (PMA) originated from the common interosseous artery and coursed alongside the median nerve. Proximal to the carpal tunnel, the median nerve bifurcated into medial and lateral branches. To our knowledge, this is the first documented case of a bilateral PMA and BMN. While the majority of existing literature focuses on a unilateral PMA or unilateral BMN, bilateral occurrences of either variation are rare. This report presents a novel finding by documenting the simultaneous presence of a bilateral PMA and BMN.

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Hand amputation is a devastating, usually accidental, injury. Re-implantation of the severed hand is a challenging procedure that requires careful planning, precise microsurgical techniques, and adequate vascular supply. Successful surgical reimplantation therefore requires foresight into unique variant neurovascular anatomy that could be encountered and how these would pose challenges during the procedure. We report the case of a successful complex re-implantation of a distal forearm traumatic amputation, sustained from a chaff cutter, in a 5-year-old male Kenyan patient. The case presented with unique variant anatomy including a persistent dominant median artery, with absent ulnar artery and superficial and deep palmar arches. The ulnar nerve also had a variant coarse that was difficult to locate. We discuss the importance of adjusting surgical approaches for optimal outcomes and highlight the challenges involved in such a complex procedure.

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Objective This pilot project aimed to assess the prevalence and variations of the median artery (MA) on a small scale in preparation for a large-scale study investigating MA in Lithuanian cadavers. Methods Eight formalin-fixed adult female cadavers were used in this study. Dissection was performed to allow for the observation of MA presence, type, origin, termination, and relations with other structures. The gathered data was analyzed, and a literature search was performed to compare the findings. Results MA was found in 10 of the 16 upper limbs examined; therefore, the incidence of MA in the present study was 62.5%. Of the 10 MAs found, six (60%) were of the antebrachial type (a-MA), and four (40%) were palmar (p-MA). Thus, the prevalence of a-MA and p-MA in the upper limbs examined was 37.5% (N = 6/16) and 25% (N = 4/16), respectively. Among the six cadavers that were found to possess MA, it was identified bilaterally in four (66.7%) and unilaterally in two (33.3%). The associations between the antimere and the presence of MA or MA-type were not statistically significant. MA most commonly originated from the common interosseous artery (50%, N = 5/10), followed by the ulnar artery (UA) (40%, N = 4/10), and the anterior interosseous artery (10%, N = 1/10). Two (33.3%) of the six a-MAs terminated in the mid-forearm, while four (66.7%) a-MAs ended in the distal forearm. Meanwhile, three (75%) of the four p-MAs terminated by joining the UA, while one (25%) terminated as the first common palmar digital artery. In the forearm, nine (90%) of the 10 MAs traveled anteriorly to the anterior interosseous nerve (AIN), and only one (10%) traveled posteriorly to the AIN. Additionally, one (10%) of the 10 MAs was found to pierce the median nerve. Conclusions Our findings confirm the variability in MA characteristics reported by previous studies. The high incidence of MA discovered in our sample calls attention to the importance of being aware of MA in a clinical setting, as this would allow for a timely and accurate response to a potential pathology associated with this structure.

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Here, we present a 37-year-old right-handed female patient who presented with increasing paresthesia, tingling, and numbness in the radial palm and lateral three fingers of her right hand for six months. Because of the intense wrist discomfort and unilateral involvement, ultrasonography was used to evaluate the patient in addition to a nerve conduction study to exclude secondary causes of carpal tunnel syndrome.

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We present the case of a 58-year-old male with a 3-day history of sudden onset headache, loss of consciousness, and uncontrolled vomiting. The patient had 3/5 quadriparesis and a Glasgow coma scale (GCS) score of 8, which merited neurocritical intensive care. Brain imaging suggested the presence of two lesions: (i) a fusiform aneurysm of 12 × 7 mm in an accessory A2 artery of the anterior cerebral artery and (ii) an unruptured saccular aneurysm of 3.3 × 2.8 mm in the distal segment of the basilar artery. He was deemed a candidate for microsurgical management. Postoperatively, he had 4/5 quadriparesis, paresis of the right oculomotor nerve, and a GCS score of 13. A 3-month follow-up showed a significant improvement in neurological function with a score of 2 on the modified Rankin scale. The presented case illustrates the relevance of a nuanced acquaintance to operate in diseased anatomical variants and complex pathologies of narrow corridors.

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PURPOSE: Arterial variations of the upper limb may bear high importance for many clinical procedures, including the use of flaps in plastic surgery. We present a feasible way for visualization and confirmation of presence of these variations. METHODS: All variations were detected by ultrasonography and confirmed by Color Doppler Imaging. Proper documentation was taken in order to present our findings. RESULTS: We report a case of a 19-year-old female who showed two concomitant arterial variations of the forearm and the hand bilaterally. These two variations were the persistent median artery and the superficial dorsal branch of the radial artery which both significantly contributed to the blood supply of the hand. All examinations were performed by the same investigator and all findings were reviewed by an experienced sonographist. CONCLUSION: An unusual arrangement of the arterial system can be easily detected. We present a feasible way to prevent iatrogenic injuries and increase utilization of anatomical variants knowledge in surgery by using ultrasound prior to planning surgical procedures.

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During a routine cadaveric dissection of a 93-year-old male donor, unique arterial variations were observed in the right upper extremity. This rare arterial branching pattern began at the third part of the axillary artery (AA), where it gave off a large superficial brachial artery (SBA) before bifurcating into the subscapular artery and a common stem. The common stem then gave off a division for the anterior and posterior circumflex humeral arteries, before continuing as a small brachial artery (BA). The BA terminated as a muscular branch to the brachialis muscle. The SBA bifurcated into a large radial artery (RA) and small ulnar artery (UA) in the cubital fossa. The UA branching pattern was atypical, giving off only muscular branches in the forearm and a deep UA before contributing to the superficial palmar arch (SPA). The RA provided the radial recurrent artery and a common trunk (CT) proximally before continuing its course to the hand. The CT from the RA gave off a branch that divided into anterior and posterior ulnar recurrent arteries, as well as muscular branches, before it bifurcated into the persistent median artery (PMA) and the common interosseous artery. The PMA anastomosed with the UA before entering the carpal tunnel and contributed to the SPA. This case presents a unique combination of arterial variations in the upper extremity and is clinically and pathologically relevant.

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The median artery is a transient embryological structure that normally disappears with the development of the radial and ulnar arteries. In rare instances, though, it persists as the persistent median artery (PMA). The superficial and deep palmar arches are formed through the anastomoses of the radial and ulnar arteries, giving hand and digits their main blood supply. This complex network of vessels and their anastomoses are prone to anatomical variations based on how the anastomosis occurs and which arteries contribute to this anastomosis. While it normally forms through the anastomosis of the radial and ulnar arteries, the superficial palmar arch (SPA) may also form differently, as in our case here, where the median artery persisted and branched off the radial artery, anastomosing with the ulnar artery to give rise to the SPA. This may also interfere with the normal compartmental architecture within the hand, possibly contributing to various clinical pathologies like carpal tunnel syndrome (CTS). Notably, in addition to the persistent median artery, our findings revealed a reversed palmaris longus and a bifid median nerve. These two additional variations can potentially exacerbate the risk of CTS. Alone, the coexistence of the PMA and the reversed palmaris longus is deemed a rare anomaly, only reported once in the literature. The addition of a third variation to the existing ones, like the bifid median nerve, is first reported by us and calls for more investigation for a possible genetic mutation. In this case, we report a persistent median artery, reversed palmaris longus muscle, and bifid median nerve in the forearm of a male cadaver found during a routine anatomy teaching session.

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PURPOSE: This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA coexisted with a bilateral bifid median nerve (MN) and two bilateral interconnections (ICs characterized with the symbol -) of the MN with the ulnar nerve (UN) (MN-UN) and a unilateral reverse IC (UN-MN). Emphasis was given to the artery's developmental background. METHODS: The PMA was identified in an 80-year-old formalin-embalmed donated male cadaver. RESULTS: The right-sided PMA terminated at the wrist, posterior to the palmar aponeurosis. Two neural ICs were identified: the UN joined the MN deep branch (UN-MN), at the forearm's upper third, and the MN deep stem joined the UN palmar branch (MN-UN), at the lower third (9.7 cm distally to the 1st IC). The left-sided PMA ended in the palm giving off the 3rd and 4th proper palmar digital arteries. An incomplete superficial palmar arch was identified by the contribution of the PMA, radial, and ulnar arteries. After the MN bifurcation into superficial and deep branches, the deep branches formed a loop, that was penetrated by the PMA. The MN deep branch communicated with the UN palmar branch (MN-UN). CONCLUSIONS: The PMA should be evaluated as a causative factor of carpal tunnel syndrome. The modified Allen's test and the Doppler ultrasound may detect the arterial flow and the angiography may depict the vessel thrombosis in complex cases. PMA could also be a "salvage" vessel for the hand supply, in radial and ulnar artery trauma.

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INTRODUCTION: Cadaveric studies suggest an increasing prevalence of the persistent median artery (PMA) over a prolonged timeframe. The aim of this retrospective cross-sectional study was to evaluate the PMA prevalence in haemodialysis patients who had computed tomographic fistulograms (CTFs), and if present, their calibres and origins. METHODS: All consecutive adult patients referred for an upper limb CTFs for assessment of arteriovenous fistula (AVF) dysfunction from 2006 to 2021 were included. Patients whose CTF did not include the forearm were excluded. PMA was identified as an artery running alongside the median nerve between flexor digitorum superficialis and flexor digitorum profundus. Patient demographics, presence of PMA including size and origin were recorded. RESULTS: A PMA was found in 91/170 (53.5%) CTFs (7:3 male-to-female ratio, mean age 71-years). When stratified by age, prevalence increased with decreasing age; 51% in >70-year-olds, 54% in 50-70-year-olds and 67% in <50-year-olds. The average PMA diameter was 2.2 mm proximally and 1.8 mm distally. No stenosis was observed in the PMAs. CONCLUSION: The PMA prevalence appears to increase with decreasing age and is a frequently encountered anatomical variant. Radiologists assessing forearm vasculature need to be aware of this anatomical variant and potentially include it in their future reports. Further research into the PMA may make its potential use as arterial conduits for AVF, potential donor grafts for coronary artery bypass surgery or additional vascular access options possible. Whether the reducing prevalence with age reflects an overall increasing prevalence is yet to be determined.

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OBJECTIVES: Thrombosis of the persistent median artery (PMA) is a rare cause of acute carpal tunnel syndrome (ACTS). Existence of a congenitally absent radial artery in this setting has not been described in the literature. METHODS: Computed Tomography Angiography (CTA) and doppler screening were used in pre surgical planning. Open surgical decompression was achieved through the release of the flexor retinaculum in the left hand. A regimen of 100 mg of Aspirin for 3 months time was initiated to encourage clot resolution and recanalization of the thrombosed artery. RESULTS: The PMA was found to be abnormally large measuring approximately 4 mm in diameter. Visible clotting off of the PMA in keeping with the doppler scans with maintenance of distal flow and was left intact with the hopes that it would recanalize over time. At the 3-month post-op review the antiplatelet therapy was ceased and the patient was symptom free, demonstrated no signs of ischaemia in the hand, and had returned to full functionality and physical activity. CONCLUSIONS: Although infrequently encountered, the knowledge of the anatomical variations of the forearm and hand together with doppler screening and CTA is essential to the surgical management of ACTS.

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Carpal tunnel syndrome (CTS) is an upper extremity median nerve entrapment disorder that is rare in children and adolescents. Anatomical variations of the wrist, such as anomalous muscles, persistent median artery (PMA), and bifid median nerves (BMN), are rare etiology of CTS. Coexistence of all three variants combined with CTS in adolescents has been rarely reported. Case description: A 16-year-old right-hand dominant male presented to our clinic with several years of bilateral thenar muscle atrophy and weakness but no paresthesia or pain in his both hands. Ultrasonography showed that the right median nerve become significantly thinner, and the left median nerve was split into two branches by PMA. Magnetic resonance imaging (MRI) revealed that anomalous muscles in the bilateral wrist extending to the carpal tunnel, causing compression of the median nerve. Considering the possibility of CTS clinically, the patient underwent bilateral open carpal tunnel release without resection of anomalous muscles and PMA. The patient has no discomfort after 2 years. This suggests that anatomical variations of the carpal tunnel may contribute to CTS, which can be confirmed by preoperative ultrasonography and MRI, and the possibility of carpal tunnel anatomical variations should be considered when CTS occurs in adolescents. Open carpal tunnel release is an effective treatment for juvenile CTS without the need to resect abnormal muscle and PMA during the operation.

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The superficial palmar arch is an important anatomical structure that contributes to the arterial supply of the palmar side of the hand in the upper extremity. However, there is limited information on the embryological morphological structure of the superficial palmar arch in the literature. We studied the types of the superficial palmar arch and determined their variations by dissecting 80 upper extremities of 40 formalin-fixed human fetuses (19 males, 21 females) 18-37 weeks of age. The types and variations of the superficial palmar arch were examined, and the median artery was imaged. The superficial palmar arch type was complete in 58 hands (72.5%) and incomplete in 22 hands (27.5%). The complete group consisted of type A (47.5%), type B (16.25%), type C (3.75%), type D (1.25%), and type E (3.75%). On the other hand, the incomplete group consisted of type F (15%), type G (8.75%), type H (2.5%), and type I (1.25%). A median artery that originated from the ulnar artery and passed through the carpal tunnel during its course was detected in two hands (2.5%). Knowledge of the superficial palmar arch variations will contribute to hand microsurgery particularly in vascular graft and free flap application interventions for arterial bleeding in the palmar region.

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The superficial palmar arch (SPA) is an important anastomotic network primarily formed by the superficial branch of the ulnar artery with one of the superficial branches of the radial artery. SPA variations were observed in three out of 20 cadaveric hand specimens. Two cases of unilateral incomplete SPA and the third case of a unilateral ulnar-to-median complete SPA were recorded. The incomplete SPA was located superficial to the flexor digitorum tendons and deep to the palmar aponeurosis. SPA in the remaining 17 hands was anatomically normal, with major contributions from the superficial palmar branch of the ulnar artery and minor contributions from the superficial palmar branch of the radial artery. These variations are clinically important, especially during procedures like arterial blood sampling, cardiac catheterization, and hemodialysis. Thus, anatomical variabilities in this region may cause complications with vascular occlusion if not ascertained before the procedure.

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The presence of both a superficial ulnar artery (SUA) and persistent median artery (PMA) of antebrachial type is of both clinical and surgical significance. In an 84-year-old female cadaver received through the Gift Body Program at Saint Louis University School of Medicine, the right brachial artery was seen divided into an SUA and radial artery (RA) slightly below the interepicondylar line of the humerus. At the level of the radial neck, the RA sent out the common interosseous artery that then gave off the radial recurrent artery before bifurcating into anterior interosseous artery (AIA) and posterior interosseous artery. The AIA continued to appear to branch into the anterior ulnar recurrent artery and posterior ulnar recurrent artery, as well as a PMA of the antebrachial type. In the hand, the SUA and RA contributed to the complete superficial palmar arch seemingly equally, and the RA was the dominant contribution to the deep palmar arch. Ninety-one other arms were assessed for this variation, and none were observed. Knowledge of an anatomical variation such as this may lead to decreased complications in the planning of surgical bypass grafting.

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Background: The median artery is an embryonic structure that typically regresses during gestation. Occasionally, the artery remains and is then termed a persistent median artery (PMA). A PMA can be associated with other anatomic anomalies, and has been known to contribute to carpal tunnel syndrome (CTS). Recent literature has observed an increase in PMA prevalence, speculated to indicate microevolutionary change. We performed a prospective observational study to investigate the current prevalence rate of PMA in patients undergoing carpal tunnel release (CTR). Methods: Institutional review board approval was obtained. From October 2020 to January 2021, patients ≥18 years old undergoing open CTR by 9 orthopaedic hand surgeons were included in analysis. Patients undergoing endoscopic CTR were excluded. Intraoperatively, the carpal tunnel was evaluated for the presence of a PMA, median nerve anomalies, or any other anatomic anomalies. If a patient underwent bilateral CTR during the study, only one side was included in analysis as determined randomly. Results: Three hundred and sixty open CTRs in 327 patients were performed during the study. Twenty-seven PMAs were identified, for an overall prevalence rate of 8.3%. The average age of patients with a PMA was 63.6 years (SD 13.3 years), consisting of 15 men and 12 women. There were no statistical differences in age, gender, or laterality between patients that did and did not have a PMA. Thirty-three patients underwent bilateral CTR during the study, with 3 being found to have a PMA unilaterally, and zero having a PMA bilaterally. Two bifid median nerves (0.6%) were also identified. Conclusion: This study represents the highest prevalence rate of PMA directly observed in CTR patients reported to date (8.3%). A PMA is not a rare finding, and it should be recognized and protected during CTR. Occasionally, a PMA can be the cause of an acute presentation of CTS.

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PURPOSE: The purpose of this study is to characterize the division of the median nerve by the persistent median artery (PMA) and highlight the associated clinical implications. Penetration of the median nerve by the PMA is believed to cause compression of the median nerve and affect nerve conduction velocity. This paper explored whether the origin and the pattern of PMA dictate its ability to divide the median nerve. METHODS: Origin, and relationship of the PMA to the median nerve were documented in 60 cadavers donated to the Human Anatomy Program at UT Health San Antonio. Entire path of this artery was followed in the forearm and the hand. RESULTS: Twenty-five cases of a persistent median artery (PMA) were found in the upper limbs (20.83%; 25/120) of these donated cadavers. Most of the persistent median arteries originated from the ulnar artery (48%; 12/25) and the others originated either from the anterior interosseous artery (36%; 9/25) or from the common interosseous artery (16%; 4/25). Sixty percent (15/25) of the persistent median arteries penetrated and divided the median nerve in the forearm. Interestingly, all the persistent median arteries that originated from the ulnar artery (100%; 12/12) divided the median nerve in the forearm and a palmar type of PMA was found to be more likely to divide the median nerve. CONCLUSION: Clinicians performing surgeries in the forearm and hand need to be aware of this anomaly and should screen patients for the presence of this artery prior to surgical intervention.

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Being aware of the variants of upper extremity anatomy is of utmost importance to a surgeon. This case report describes a patient who presented with two separate wrist masses. Operative exploration was planned, and both the structures were investigated. The distal mass was identified as a volar wrist ganglion, and the more proximal mass was identified as the muscle belly of a reversed palmaris longus muscle. Incidentally, it was noted that the patient had a patent, persistent median artery. Although many variants of the palmaris longus have been described, as have been cases of a persistent median artery, both have not been previously documented in a single patient. Although this is rare, having knowledge of possible anatomic variations is valuable for any surgeon operating on the upper extremity.

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BACKGROUND: It is vital to know the anatomical variations of the wrist to avoid iatrogenic injuries during carpal tunnel (CT) surgery. PURPOSE: To determine the anatomical variations of the median nerve (MN) and the prevalence of persistent median artery (PMA) on wrist magnetic resonance imaging (MRI). MATERIAL AND METHODS: A total of 300 wrists evaluated by MRI during 2013-2015 were retrospectively identified. While branching of the MN distal to the CT is accepted as the normal anatomy, proximal to the tunnel and within the tunnel were considered as variations. The prevalence of PMA was also evaluated. The patients were assigned to groups according to age, gender, and wrist side and compared to determine whether there was any significant difference in terms of these variations. All evaluations were assessed with the shared decision of a musculoskeletal radiologist and a radiology resident. RESULTS: Of the 300 wrists, 38 (12.7%) and 34 (11.3%) had a bifid MN proximal to the CT and within the CT, respectively. Only one nerve trifurcation was seen within the CT. The MN exhibited branching distal to the CT in 227 (76%) patients. PMA was observed in 44 (14.7%) patients. Of the 44 PMA cases, 28 (63.6%) also had a coexisting MN variation. There was no significant difference in the prevalence of MN variations and PMA in the subgroups (P > 0.05). CONCLUSION: Nearly one in four patients (24.4%) have MN variations and 14.8% had PMA. Preoperative evaluation of these common anatomical variations with MRI will be protective against postoperative complications of CT surgery.

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