An unusual spontaneous recanalization by multiple palmar arteriovenous connections of a chronically occluded radiocephalic hemodialysis fistula

Preservation of a vascular access is crucial in the management of hemodialysis patients. In this regard, percutaneous transluminal angioplasty (PTA) is an effective tool if performed after an adequate understanding of preliminary fistulograms. The present case showed a chronic dysfunction of a radial-cephalic arteriovenous fistula (AVF) due to arterial occlusion and partially relieved by the spontaneous development of multiple small arteriovenous connections in the palmar region of the hand. This dense network had been so far able to ensure a sufficient retrograde blood flow for an effective hemodialytic performance. The angioplasty of the post-anastomotic stenotic segment of the radial artery was effective in restoring this neoformed AVF patency.

Anatomical variations of the superficial palmar arch in human fetuses

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.

Variations in Superficial Palmar Arch: Case Series with Clinico-anatomical Perspective

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.

A Unique Branching Pattern of the Brachial Artery: Coexisting Superficial Ulnar Artery and Persistent Median Artery

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.

Anatomical variations of the superficial palmar arch and its clinical relevance

Background/Aim. In-depth knowledge of the vascular net-work of the hand is of great importance in modern medicine. The main vessel of the hand is the superficial palmar arch (SPA). As typically described in anatomical textbooks, it arises as a terminal branch of the ulnar artery, which then anastomoses with the superficial palmar branch of the radial artery. However, the SPA is characterized by remarkable variability, which has been the area of interest of many researchers so far. The aim of this study was to exert a comprehensive examination of the anatomy of the SPA. Methods. The research was conducted at the Institute of Anatomy ?Niko Miljanic? on a total number of 14 cadavers. After careful dissection, variations of the modality of formation of the SPA and its distance of the SPA from Kaplan?s cardinal line were observed on the right hands. Collected data were then analyzed statistically in SPSS 11.0 using the Mann-Whitney U test, with the accepted level of statistical significance of p < 0.05. Results. According to Coleman and Anson?s classification, the higher incidence of the incomplete type (57.14%) of the SPA was observed compared to the complete type (42.86%). In addition to this, a statistically significant difference was discovered in the distance of the SPA from Kaplan?s cardinal line between two groups with complete and incomplete types, respectively. The parameter examined in the group with the complete type took the value of 2.13 ? 0.32 cm, while in the group with the incomplete type measured 3.33 ? 0.87 cm. Conclusion. The present study showed a very important complexity in the domain of anatomy of the SPA with numerous clinical implications. For that reason, a thorough evaluation of the hand circulatory system should be considered while planning surgical procedures in order to avoid operative and postoperative complications.

Evaluation of hyperspectral imaging to quantify perfusion changes during the modified Allen test

OBJECTIVES

To evaluate the capability of hyperspectral imaging (HSI), a contact-less and noninvasive technology, to monitor perfusion changes of the hand during a modified Allen test (MAT) and cuff occlusion test. Furthermore, the study aimed at obtaining objective perfusion parameters of the hand.

METHODS

HSI of the hand was performed on 20 healthy volunteers with a commercially available HSI system during a MAT and a cuff occlusion test. Besides gathering red-green-blue (RGB) images, the perfusion parameters tissue hemoglobin index (THI), (superficial tissue) hemoglobin oxygenation (StO2), near-infrared perfusion (NIR), and tissue water index (TWI) were calculated for four different regions of interest on the hand. For the MAT, occlusion (OI; the ratio between the condition during occlusion and before occlusion) and reperfusion (RI; the ratio between the non-occlusion state and the prior occlusion state) indices were calculated for each perfusion parameter. All data were correlated to the clinical findings.

RESULTS

False-color images showed visible differences between the various perfusion conditions during the MAT and cuff occlusion test. THI, StO2, and NIR behaved as expected from physiology, while TWI did not in the context of this study. During rest, mean THI, StO2, and NIR of the hand were 34 ± 2, 72 ± 9, and 61 ± 6, respectively. The RI for THI showed a roundabout threefold increase after reperfusion of both radial and ulnar artery and was thus, distinctly pronounced when compared with StO2 and NIR (~1.25). The OI was lowest for THI when compared with StO2 and NIR.

CONCLUSIONS

HSI with its parameters THI, StO2, and NIR proved to be suitable to evaluate perfusion of the hand. By this, it could complement visual inspection during the MAT for evaluating the functionality of the superficial palmary arch before radial or ulnar artery harvest. The presented RI might deliver useful comparative values to detect pathological perfusion disorders at an early stage. As microcirculation monitoring is crucial for many medical issues, HSI shows potential to be used, besides further applications, in the monitoring of (free) flaps and transplants and microcirculation monitoring of critically ill patients.

Salvage of a Radiocephalic Arteriovenous Hemodialysis Fistula by Percutaneous Angioplasty to Increase Retrograde Flow from the Palmar Arch in Patients with an Occluded Radial Artery

This brief report presents 12 patients who underwent percutaneous transluminal angioplasty (PTA) to increase the retrograde blood flow from the palmar arch. All the patients had radiocephalic arteriovenous fistulas with occluded feeding arteries. The technical success rate was 100%. Three patients (25.0%) underwent surgical repair for restenosis, 2 patients (16.6%) underwent surgical repair for other reasons, 5 patients (41.8%) underwent repeated PTAs for restenosis, and 2 patients (16.6%) had no further treatment. The target lesion primary patency rates at 6, 12, 36, and 60 months were 90.9%, 54.5%, 36.4%, and 18.2%, respectively.

Assessment of collateral hand circulation by modified Allen's test in normal Indian subjects

BACKGROUND

Allen's test (AT) and Modified Allen's Test (MAT) are used as screening methods for assessment of the hand circulation. Few people lack the dual blood supply of hand and are at risk of hand ischemia after any intervention on radial artery. The Purpose of the study was to assess the collateral circulation of hand using MAT in normal Indian subjects and in elderly population to know the prevalence of positivity of Allen's test.

METHODS

900 participants (1800 hands) were divided in two groups. Group I had participants with age <50 years and group II had participants with age ≥50 years. MAT was performed in all participants and results were compared between the two groups.

RESULTS

In group I (n = 450, 900 hands), 313 were males and 137 were females, with mean age of 35.04 years. The relative percentages of a normal, equivocal, borderline and abnormal MAT were 77.8%, 16.6%, 3.7% and 1.6%, respectively. In group II (n = 450, 900 hands), 248 were males and 202 were females, with mean age of 60.4 years. The relative percentages of a normal, equivocal, borderline and abnormal MAT were 69.0%, 18.6%, 6.60% and 5.66%, respectively. A positive/abnormal test was significantly more common (5.66% Vs 1.66%, P < 0.00001) in older group.

CONCLUSION

MAT is simple, time tested and non invasive test to assess collateral circulation of the hand. A negative MAT safely selects patients for radial artery harvest; however, if the test is positive and in older patients then a second objective test may be needed.

Variations in the origins and absence of the common digital arteries of the hand: a cadaveric study

We studied anomalies of the common digital arteries by dissecting 33 fresh cadaver hands under magnification. In the majority of the dissected hands (25 hands), common digital arteries took off from the superficial palmar arch and ran superficial and parallel to the flexor tendons. Variations were found in eight out of 33 hands. In four hands the common digital artery to the second web space was replaced by an atypical vessel, originating from the deep palmar arch, that crossed posterior to the index flexor tendons proximal to the A1 pulley. In eight hands, the common digital artery to the fourth web space was replaced by an atypical deeper vessel, originating from the superficial palmar arch and crossing posterior to the little finger flexors. No nerve anomalies were identified. Unrecognized, these atypical arteries to the second and/or fourth web spaces could lead to vascular complications during surgery, especially pollicization.

Transulnar approach as an alternative to transradial approach in non-coronary intervention: safety, feasibility and technical factors

Purpose

Transulnar access (TUA) has been shown to be an effective alternative to transradial access (TRA) for coronary intervention. This study evaluates the safety and efficacy of TUA in patients undergoing visceral interventions in the setting of contraindication to TRA.

Materials and Methods

Patients who underwent visceral interventions via ulnar approach were included in the study. Outcome variables include technical success, access site and bleeding complications.

Results

From May 2014 to September 2016, TUA was attempted 17 times in 14 patients (mean age: 60 years; range: 27 to 81 years) for whom TRA was planned for visceral intervention, but contraindicated. Contraindication to TRA included Barbeau D waveform (n = 3), radial artery diameter <2 mm (n = 8), known radial loop (n = 2), high takeoff of the radial artery (n = 2), prior radial artery occlusion (RAO) (n = 1), and radiocephalic arteriovenous fistula (n = 1). Interventions included selective internal radiation therapy (SIRT) (n = 4), SIRT mapping (n = 2), chemoembolization (n = 6), renal embolization (n = 1) and bland liver embolization (n = 4). Technical success was achieved in 94.1% (16/17 cases) with the single failure attributed to an inability to cannulate the target vessel due to vessel tortuosity, requiring ipsilateral femoral crossover. There were no major access site or bleeding complications. Minor adverse events include two access site hematomas, which were successfully treated with conservative management.

Conclusions

TUA for visceral interventions is a safe and effective alternative to femoral approach when TRA is contraindicated.