Fenestration of the facial nerve by the stylomastoid artery

BACKGROUND

Anatomic landmarks such as the tympanomastoid suture line, posterior belly of the digastric muscle, tragal pointer, and styloid process can assist the parotid surgeon in identifying and preserving the facial nerve. Vascular structures such as the posterior auricular artery and its branch, the stylomastoid artery, lay in close proximity to the facial nerve and have been proposed as landmarks for the identification of the facial nerve. In this case report, we describe an anatomic variation in which the stylomastoid artery has fenestrated the main trunk of the facial nerve, dividing it in two.

METHODS

Two patients underwent parotidectomy (one for a pleomorphic adenoma, the second for a parotid cyst) through a standard anterograde approach with identification of the usual facial nerve landmarks.

RESULTS

The appearance of the main trunk of the facial nerve was unusual in both patients due to its being fenestrated by the stylomastoid artery. The stylomastoid artery was divided, and the remainder of the facial nerve dissection was performed uneventfully with subsequent resection of the parotid mass in both patients.

CONCLUSIONS

In rare instances, the stylomastoid artery can penetrate through the common trunk of the facial nerve. This is an important anatomic variant for the parotid surgeon to be aware of, as it can increase the difficulty of facial nerve dissection.

Case Report: Incidental finding of an atresia of the inferior vena cava-a challenge for cardiac surgery

Inferior vena cava atresia is a rare and usually asymptomatic condition. However, when these patients undergo cardiac surgery, it can present an unexpected and challenging situation for the surgeon. Specifically, adequate venous drainage during cardiopulmonary bypass (CPB) is a critical issue here and may require an extension of cannulation strategies. Adequate preoperative diagnostics, ideally with imaging modalities such as CT angiography or MRI, are required for optimal surgical planning. Here, we describe a rare case of thoracic ascending aortic aneurysm with concomitant inferior vena cava atresia that was successfully operated on. With adequate preoperative planning, we were able to perform an operation without unforeseen complications with standard initialization of CPB.

Presence of anomalous flexor carpi radialis brevis (FCRB) in Madelung's deformity

An anomalous flexor carpi radialis brevis (FCRB) muscle was present in four of nine patients undergoing surgery for Madelung's deformity. This disproportionately frequent finding suggests an embryologic dysgenesis of forearm formation rather than a developmental tethering of Vicker's ligament.Level of evidence: IV (case series).

Imaging findings of arrested pneumatisation and differentiation from other skull base lesions

OBJECTIVES

Arrested pneumatisation (AP) is an anatomic variant of the sphenoid sinus. Since AP remains underrecognised, otolaryngologists and radiologists may mistake AP for a lesion and perform follow-up imaging studies. We investigated the imaging findings of CT, MRI, and F-18 fludeoxyglucose (FDG)-positron emission tomography (PET) for AP, and discussed the differences between AP and other skull base lesions.

METHODS

We reviewed multidetector low CT imaging of 442 patients (285 men and 157 women; age range, 19-93 years; mean age, 67.8 years) who underwent FDG-PET/CT for head and neck tumours between January 2019 and December 2019. The imaging findings of AP were reviewed on CT, MRI, FDG-PET/CT, and compared with those of fibrous dysplasia, chordoma, chondrosarcoma, multiple myeloma, and bone invasion of nasopharyngeal carcinoma.

RESULTS

AP was identified in 22 patients (14 men and 8 women; age range, 24-93 years; mean age, 67.0 years) based on criteria from previous reports. AP manifested with well-circumscribed sclerotic margins on CT, without evidence of expansion. AP showed high-signal intensity on T1-/T2 weighted MRI. FDG-PET revealed non-significant uptake [maximum standardised uptake value (SUVmax): 0.85 (range, 0.4-1.27)] in AP. Contrastingly, skull base lesions showed expansion, poorly circumscribed boundaries without osteosclerotic margins, and moderate-to-severe FDG uptake (SUVmax: 1.8-8.4).

CONCLUSIONS

The characteristic imaging findings of AP, namely non-expansile on CT and non-uptake on FDG-PET, may aid in its differentiation from other skull base lesions.

Unilateral Anomalous Origin of Dorsalis Pedis Artery From Peroneal Artery in a Cadaver

In normal anatomy, the anterior tibial artery is typically the first branch of the popliteal artery before it becomes the tibioperoneal trunk. The normal course of the anterior tibial artery includes piercing through the interosseus membrane and continuing through the anterior compartment. It then continues onto the dorsum of the foot as the dorsalis pedis artery at the level of the malleoli. We describe a unique case of an anomalous origin of the dorsalis pedis artery from the peroneal artery. It is important for vascular surgeons to be aware of this variant while interpreting arteriograms of the lower extremity. It can be easily misinterpreted as an occluded distal anterior tibial artery with reconstitution of the dorsalis pedis artery from the collaterals.

Vieussens' Arterial Ring: Historical Background, Medical Review and Novel Anatomical Classification

In coronary artery disease, the presence of Vieussens' arterial ring (VAR), a ring-shaped anastomosis between the conus branch of the right coronary artery with the left anterior descending artery (LAD), will allow blood flow to return to the obstructed coronary system. We have conducted a literature review, aiming to collect all the existing information about the documented VAR cases and any related pathological conditions. A total of 54 studies entered the review, including 56 patients. The mean age of the patients was 56.12 ± 16.2 years. Angina was present in 53.6% of the patients, with 7.2% of the cases being asymptomatic. Coronary artery disease outweighed (58.9%) as the patients' most frequent diagnosis. We propose a novel VAR anatomical classification, based on the sites of origin and termination of its course, with six distinct types, for a better understanding and surgical management of VAR. Type IA, originating from the conus branch and terminating in the proximal segment of the LAD was most frequently reported (51.8%). The recognition and the subsequent evaluation of the ring's anatomy and course are crucial for a customized clinical intervention. When right and left coronary angiographies fail to reveal any collateral circulation, selective conus artery catheterization should be in order. The proposed classification offers a manageable and comprehensive context for the assessment, evaluation and planning of therapeutic strategies of VAR and sets a new terminology frame for treatment guidelines.

Anomalous duplication of the portal vein with prepancreatic postduodenal portal vein

Objective: We report a case of unusual anomalous duplication of the portal vein. Patient: A 40-year-old man with portal vein duplication. One portal vein is derived from the superior mesenteric vein and splenic vein and enters the caudate lobe of the liver. Another portal vein, known as the prepancreatic postduodenal portal vein, is derived from the superior mesenteric vein and courses anterior to the pancreas and posterior to the duodenum. Conclusion: Duplication of the portal vein is an extremely rare developmental anomaly, and in previous reports, the superior mesenteric and splenic veins entered the liver separately. We present a previously unreported case of anomalous duplication of the portal vein, one of which was the prepancreatic postduodenal portal vein.

The Intraseptal Course of the Superficial Peroneal Nerve: An Anatomic Study

BACKGROUND

Anatomic and clinical studies show many variants of the superficial peroneal nerve (SPN) course and branching within the compartments and at the suprafascial layer. The anatomy of the transition zone from the compartment to the subcutaneous layer has been occasionally described in the literature, mainly in studies reporting the intraseptal SPN variant in 6.6% to 13.6% of patients affected by the SPN entrapment syndrome. Despite the little evidence available, the knowledge of the transition zone is relevant to avoid iatrogenic lesions to the SPN during fasciotomy, open approaches to the leg and ankle, and SPN decompression. Our anatomic study aimed to describe the SPN transition site and to evaluate the occurrence of a peroneal tunnel and of an intraseptal SPN variant.

METHODS

According to the institutional ethics committee requirements, 15 fresh-frozen lower limbs were dissected to study the SPN course and its branching, focusing on the transition site to the suprafascial layer.

RESULTS

The SPN was located in the anterior compartment in 2 cases and in the lateral in 13. An intraseptal tunnel was present in 10 legs (66%), at a mean distance of 10.67 cm from the lateral malleolus. Its mean length was 2.63 cm. The tunnel allowed the passage of the main SPN in 8 cases and of its branches in two. In the remaining 5 legs (33%), the SPN pierced a crural fascia window.

CONCLUSION

In our sample a higher rate than expected of intraseptal SPN variants was found.

CLINICAL RELEVANCE

The knowledge of the anatomy of the SPN course and intraseptal variant is relevant to avoid iatrogenic lesions during operative dissection. Further studies are needed to evaluate the effective prevalence of an intraseptal tunnel, independently from the SPN entrapment syndrome, and how to avoid associated iatrogenic complications.

Middle Cerebral Artery Duplication: A Near Miss for Stroke Thrombectomy

Middle cerebral artery (MCA) duplication is a rare anatomical arrangement where an anomalous MCA arises from the distal end of the internal carotid artery. If occluded, a duplicated MCA can present with significant deficits comparable to an occlusion of the M2 vessel without obvious findings on vessel imaging via computed tomography angiography (CTA) or magnetic resonance angiography. A female in her 30s with no past medical history presented with suspected acute stroke 8 hours after last known normal-featuring new-onset right-sided weakness, facial droop, and slurred speech, which corresponds to a National Institutes of Health Stroke Scale score of 13. Head CTA was interpreted as preserved patency of intracranial vessels. CT perfusion was suggestive of a large area of penumbra. Emergent cerebral angiography demonstrated MCA duplication on the left side with proximal occlusion of the M1 branch supplying the traditional M2 territory. Mechanical thrombectomy achieved grade TICI 2b reperfusion. Throughout her hospital stay, her aphasia started to resolve, and the patient was discharged to inpatient rehabilitation. This case presents a diagnostic challenge and learning point in identifying similar patients in the future. We suggest the clinician, given a high clinical suspicion for large vessel occlusion, even if CTA is negative, to continue with CT perfusion to not miss stroke in patients with MCA duplication. If CT perfusion shows substantial deficit in an MCA distribution, one must consider that the patient may have an MCA duplication.

Prevalence of Morphological Variations Associated With Femoroacetabular Impingement According to Age and Sex: A Study of 1878 Asymptomatic Hips in Nonprofessional Athletes

Background:

Radiographic findings related to the cam and pincer variants of femoroacetabular impingement (FAI) include measurements of the alpha angle and lateral center-edge angle (LCEA). The function of these radiographic findings has been put into question because of high heterogeneity in reported studies.

Purpose:

The aim of this study was 3-fold: (1) to determine the prevalence of cam and pincer variants according to sex and age on anteroposterior (AP) pelvic radiographs from an asymptomatic nonathletic population, (2) to identify the most common radiographic signs of cam- and pincer-type variants, and (3) to determine if there are variations in the prevalence of these radiographic signs according to sex and age.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

There were 3 independent observers who retrospectively analyzed the 939 AP pelvic radiographs (1878 hips) of patients aged 18 to 50 years who did not have hip symptoms and who were not professional athletes. The prevalence of the cam and pincer variants according to the alpha angle and LCEA, respectively, and the presence of other radiographic signs commonly associated with these variables were determined in the overall population and by subgroup according to sex and age group (18-30, 31-40, and 41-50 years). Descriptive and inferential statistics were used to analyze the study sample.

Results:

The mean age of the included population was 31.0 ± 9.2 years, and 68.2% were male. The prevalence of the cam-type variant was 29.7% (558/1878), and that of the pincer-type variant was 24.3% (456/1878). The radiographic signs that were most associated with the cam and pincer variants were a pistol-grip deformity and the crossover sign, respectively. Significant differences (P < .001) in the prevalence of these variants were identified between men and women in both variants. No differences were observed in the alpha angle or LCEA according to sex or age.

Conclusion:

Radiographic findings suggestive of FAI had significant variations with respect to sex and age in this study sample. This study provides information to determine the prevalence of these anatomic variants in the general population.

Malignant right coronary artery origin from the left sinus of Valsalva: Complementary role for transesophageal echocardiography upon the cath-lab diagnosis

Anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva is a rare but clinically relevant congenital anomaly, since the RCA may be subjected to cyclical compression due to its interarterial course. At least in the past, most patients experienced bad outcomes before being diagnosed with a malignant variant. Chronic (often subclinical) myocardial ischemia and possible arrhythmias are common complications. Once symptoms or electrocardiographic signs of myocardial ischemia become apparent, a quick diagnosis is mandatory. We report the case of a late symptomatic woman in whom RCA originated from the opposite sinus of Valsalva. The malignant variant was confirmed at transesophageal echocardiography directly in the catheterization laboratory, soon after angiographic diagnosis of aberrant origin.

Managing uncommon and unexpected findings during neuromuscular ultrasound

One barrier to widespread adoption of neuromuscular ultrasound by clinical neurophysiologists is concern over how to identify and manage non-neuromuscular findings. This review addresses this concern by describing the sonographic appearance of a variety of commonly observed pathologies and anatomic variants in dermal, subcutaneous, bony, glandular, lymphatic, vascular, and other superficial tissues. Additionally, it outlines techniques to ensure proper clinical and ultrasound evaluation of unexpected or uncommon findings. Finally, it highlights strategies to manage unexpected findings, including how to best communicate findings to patients and referring clinicians to avoid unnecessary testing and ensure appropriate follow-up. Ultrasound extends the ability of the neuromuscular sonographer-clinician to contribute to patient care.

Artery of Percheron as a Rare Feeder of Hemorrhagic Thalamic Arteriovenous Malformation: A Case Report and Literature Review

Arteriovenous malformation (AVM) fed by the artery of Percheron (AOP) is extremely rare, with only one case described in the literature to date. We herein present a case of a 43-year-old female with hemorrhagic thalamic AVM mainly supplied by the AOP, who subsequently underwent conservative management and recovered well except for mild right hemiparesis. This case highlights that the AOP is a rarely recognized but clinically significant entity and should be identified when dealing with AOP-associated neurovascular disorder as described.

A Case of Polymetatarsia Without Polydactyly

Polymetatarsia is an atavistic anomaly characterised by one or more additional metatarsals. Usually found with a supernumerary digit (polydactyly), polymetatarsia without polydactyly is a rare variant. We report a case of a 34-year-old male with polymetatarsia within the first intermetatarsal spaces of both feet without polydactyly. Clinically, moderate dorsal spur formation was visible, and compressive pain from ankylosed additional metatarsals within the first intermetatarsal spaces was exhibited. Treatment involved resection of his additional metatarsals with concomitant correction of his hallux valgus deformities and bilateral second brachymetatarsia. He reported a reduction in pressure and pain that was maintained until his discharge appointment at six weeks postoperatively. Resection of additional metatarsals may provide effective pain relief in symptomatic patients.  

Anomalous Origin of the Anterior Choroidal Artery Proximal to an Ipsilateral Fetal Posterior Cerebral Artery: Case Report of an Extremely Rare Anatomic Variant and Discussion of its Clinical Implications

The anterior choroidal artery (AChA) supplies important cerebral structures such as the internal capsule, optic tract, and lateral geniculate body. It is normally a branch of the communicating segment of the internal carotid artery (ICA) with significant neurological symptomatology if injured. Typically, the AChA originates distal to the posterior communicating artery (PCoA), but rare variants have previously been described. Such anatomical differences are particularly important entities, especially in the context of neuroendovascular procedures, as inadvertent damage to these arteries can have devastating consequences. In this case report, we present an unusual anatomical pattern of the right AChA arising proximal to an ipsilateral fetal PCA.

Cutaneous Branch of the Obturator Nerve Extending to the Medial Ankle and Foot: A Report of Two Cadaveric Cases

The area of skin supplied by the cutaneous branch of the obturator nerve (CBO) is highly variable. Although most introductory anatomy texts describe the CBO as innervating only a portion of the medial thigh, there are numerous reports in the literature of CBOs passing the knee to innervate the proximal, middle, or even distal leg. There are no previous reports of CBOs extending to the ankle and foot. Herein we describe 2 cases of CBOs extending at least to the medial foot. Both cases were discovered incidentally, during routine cadaver dissections by osteopathic and podiatric medical students in the anatomy laboratory of Western University of Health Sciences in California. In both instances, the anomalously long CBOs shared several characteristics: (1) they arose as direct branches of the anterior division of the obturator nerve, not from the subsartorial plexus; (2) they coursed immediately posterior to the great saphenous vein from the distal thigh to the distal leg, only deviating away from the saphenous vein just above the medial malleolus; and (3) they terminated in radiating fibers to the posterior half of the medial ankle and foot. In both cases, the saphenous branch of the femoral nerve was present but restricted to the area anterior to the great saphenous vein. It is likely that the variant CBOs carried fibers of the L4 spinal nerve and thus provided cutaneous innervation to the medial foot and ankle, a function most commonly reserved for the saphenous branch of the femoral nerve distal to the knee. Saphenous neuropathy is a common postoperative complication of saphenous cutdowns for coronary artery bypass grafts, so the potential involvement of a long CBO can add additional complexity to regional anesthetic blocks for foot and ankle surgery and procedures such as vein harvesting for coronary artery bypass grafts.

Treatment of an aberrant inferior temporal artery aneurysm arising off the proximal cavernous segment of the internal carotid artery

We report the clinical details, imaging findings, and management of a 41-year-old female who presented with 6^th cranial nerve palsy from a right proximal cavernous segment internal carotid artery aneurysm arising distal to the branch point of an aberrant inferior temporal artery. Although rare, aberrant branches arising off the proximal ICA may supply the cerebral cortex. Careful evaluation prior to surgical intervention in this setting may reduce the incidence of ischemic complications.

May-Thurner Syndrome in Operative Ankle Fracture Dislocations: A Case Report

May-Thurner syndrome (MTS) is a rare condition in which patients develop iliofemoral deep venous thrombosis owing to an anatomic variant in which the right common iliac artery overlies and compresses the left common iliac vein against the lumbar spine. Data regarding lower extremity trauma in patients with previously diagnosed MTS are rare. We discuss the operative approach for ankle trauma occurring 3 weeks after endovascular surgery for the treatment of MTS.

Case Report of Diagnostic Evidence Depicting Palmaris Longus Origin Reversal: Ultrasound and MRI Evaluation

INTRODUCTION

The palmaris longus (PL) is very prone to anatomical variance. It may exhibit agenesis, reversal, and duplication. The reversal variant presents with the PLtendinous aspect proximally and the muscle belly distally. It is an important finding, and it is important to consider when making a differential diagnosis. This is the only reported case of a left distal forearm PLmuscle variant with ultrasound and magnetic resonance imaging (MRI) in a Caucasian adult male.

CASE REPORT

A 28-year-old Caucasian male presented to the clinic with an abnormal ultrasound finding of a left wrist mass. The patient was instructed to get an MRI, which demonstrated and further confirmed the reversed Plmuscle.

CONCLUSION

Although rare, anatomic muscle variance may occur in many places of the body leading to symptoms that need attention. These variants should be considered in orthopedic differential diagnosis and ruled out appropriately with proper diagnostic techniques. By making the correct diagnosis, it leads to improved patient outcomes and satisfaction both conservatively and surgically.

Cross-over type of supernumerary digastric muscle

A cross-over type asymmetric anomaly of the anterior belly of the right digastricmuscle was observed during a cadaveric dissection of the submental region.Three irregularly-shaped supernumerary muscle bundles were found between theanterior bellies of the digastric muscles. Although the anomalies of the digastricmuscles are often observed, this complicated pattern has not been previouslyreported. Our findings and previous reports illustrate the morphogenetic complexityof the anterior belly of the digastric muscle, and their potential importancein confounding clinical evaluation or complicating surgical procedures in thesubmental region.

Insertion of a totally implantable venous access port in a patient with persistent left superior vena cava (PLSVC)

Persistent left superior vena cava (PLSVC) is a rare congenital variant, but it is the most common venous thoracic malformation, occurring in 0.3-0.5% of the general population. PLSVC is caused by the persistence of the embryological left anterior cardinal vein which normally obliterates and persists as the Marshall ligament. We present the case of a 74-year-old male lung cancer patient, who already underwent an uncomplicated right-hand sided pacemaker insertion in 2006. During implantation of a subcutaneous central venous access port through puncture of the left subclavian vein, a PLSVC was discovered. A venography and computed tomography confirmed the anomaly. The catheter of the central venous access port was positioned in the PLSVC with adequate drainage and flushing of blood, rendering it useful for administration of systemic chemotherapy. The patient underwent his chemotherapy cycles without major complications.

Intrathyroidal carotid artery and nonrecurring right recurrent laryngeal nerve: A case report

BACKGROUND

When performing thyroidectomy, knowledge of normal anatomy and variants is vital to avoid injuring nearby structures. Typically, the bilateral carotids course posterolateral to the thyroid gland. We describe a rare variant of an intrathyroidal carotid artery, not previously described in the literature.

METHODS

A 23-year-old woman with a strong family history of thyroid cancer presented with a left thyroid nodule, and a fine-needle aspiration biopsy revealing papillary thyroid carcinoma. She underwent total thyroidectomy.

RESULTS

Intraoperatively, the carotid was found coursing centrally through the right lobe parenchyma, associated with an ipsilateral nonrecurrent recurrent laryngeal nerve (NRLN) entering the cricothyroid joint superolaterally.

CONCLUSION

This is, to our knowledge, the first report of such an anatomic variant in the medical literature. Aberrant carotid artery anatomy may potentially cause life-threatening surgical complications and should be considered preoperatively. Furthermore, recognition of concurrent recurrent laryngeal nerve (RLN) anomalies with vascular variations allows identification of nonrecurrent nerves.

Radiographic characterization of the retroantral ethmoid cell

BACKGROUND

The retroantral ethmoid cell (RAEC) is defined as a posterior ethmoid cell that pneumatizes inferolaterally behind the posterior wall of the maxillary sinus. The RAEC can present a challenge to otolaryngologists during endoscopic ethmoidectomy due to its concealed location. It is also encountered during the endoscopic transpterygoid approach to the skull base, which requires dissection behind the posterior wall of the maxillary sinus. Because the RAEC is not described in the literature, this study aims to better characterize this anatomic variant.

METHODS

This is a retrospective review of 58 consecutive patients who underwent revision functional endoscopic sinus surgery (FESS) within a 2-year period at a tertiary referral center. Sinus computed tomography (CT) scans for this cohort (116 sides total) were reviewed independently by 3 authors to determine the incidence of the RAEC and the degree of surgical dissection during prior surgery.

RESULTS

Of the 116 sides included in the study, RAEC was identified in 19 (16%). Furthermore, 14 of 19 (74%) cells were diseased with evidence mucosal thickening or neo-osteogenesis. Of the 12 sides with RAEC that had evidence of previous posterior ethmoidectomy, 4 (33%) cells were not opened, 6 (50%) were partially opened, and only 2 (17%) were completely opened.

CONCLUSION

This study demonstrates the relatively high prevalence of the RAEC in our patient population. The majority of RAECs showed both evidence of disease and that they were not completely opened during previous surgery. Recognition of this anatomic entity may allow for more thorough ethmoidectomy.