Anatomical considerations and surgical manipulation of the rhomboid lip in microvascular decompression for hemifacial spasm.

BACKGROUND: In microvascular decompression (MVD) procedures for hemifacial spasm (HFS), surgeons often encounter a rhomboid lip which may obscure the root exit zone (REZ) of the facial nerve. This study aims to explore the anatomical variations of rhomboid lips and their surgical implications to improve safety and effectiveness in MVD surgeries. METHODS: A retrospective analysis was conducted on 111 patients treated for HFS between April 2021 and March 2023. The presence of a rhomboid lip was assessed through operative video records, and its characteristics, dissection methods, and impact on nerve decompression outcomes were further examined. Preoperative magnetic resonance imaging (MRI) scans were reviewed for detectability of the rhomboid lip. RESULTS: Rhomboid lips were identified in 33% of the patients undergoing MVD, with a higher prevalence in females and predominantly on the left side. Two distinct types of rhomboid lips were observed: membranous and cystic variations. The membranous type was noted for its smaller size and position ventral to the choroid plexus. In contrast, the cystic variation was distinguished by its larger size and a thin membrane that envelops the choroid plexus. Preoperative MRI successfully identified rhomboid lips in only 21% of the patients who were later confirmed to have them in the surgical procedures. Surgical approaches primarily involved incisions on the dorsal wall and along the glossopharyngeal nerve root, with only limited need for extensive dissection from lower cranial nerves. Immediate spasm relief was observed in 97% of the patients. One case exhibited a lower cranial nerve deficit accompanied by brainstem infarction, which was caused by the dissection from the lower cranial nerves. CONCLUSIONS: Recognizing the two variations of the rhomboid lip and understanding their anatomical structures are essential for reducing lower cranial nerve injuries and ensuring effective nerve decompression.

Developing a grading scale for the evaluation of degenerative changes in uncovertebral (Luschka) joints.

The study aimed to develop a grading scale for evaluating degenerative changes in uncovertebral joints (UVJs) found on computed tomography (CT) scans, and assess the intra- and inter-rater reliability of this scale. The study included 50 subjects (average age 55.12 ± 13.76 years) referred for CT examinations due to cervical complaints. Three researchers developed a reading protocol using a semiquantitative grading scale of UVJ degenerative changes. CTs were read and reread several times to refine the protocol. Subsequently, the reader read and reread 20 CTs (C3-C7 bilateral, altogether 200 UVJs) 2 weeks apart in order to assess the intra-rater reliability. The second reader, after the training, read the same 20 CTs (yet, C4-C6 bilateral, altogether 120 UVJs) in order to assess the inter-rater reliability. The additional 30 CTs were evaluated to analyze the prevalence and associations between the studied parameters. The final grading scale included joint space narrowing, osteophyte, subchondral sclerosis, subchondral cyst, hypertrophy, cortical erosion, and vacuum phenomenon. The intra-rater agreement ranged from very good in joint space narrowing (k = 0.757), osteophyte grade (k = 0.748), subchondral cyst (k = 0.716), hypertrophy (k = 0.728), vacuum phenomenon (k = 0.712) to good (k = 0.544) in subchondral sclerosis, and fair in cortical erosion (k = 0.36). For the overall UVJ degeneration grade, the intra-rater agreement was very good (k = 0.616) and the inter-rater reliability was good (k = 0.468). 77.6% of the evaluated UVJs exhibited some degenerative changes. Our grading scale is the first to evaluate UVJs presenting good-very good intra-rater and inter-rater reliability which can be utilized in further clinical studies and assess degenerative changes in UVJs.

Preliminary results in anterior cervical discectomy and fusion with the uncovertebral joint fusion cage in a goat model.

OBJECTIVE: To preliminarily evaluate the safety and efficacy of the uncovertebral joint fusion cage in a goat model of cervical spine interbody fusion. METHODS: Twenty-four healthy adult goats were randomly assigned to one of the two following groups: Group A, goats were implanted with an uncovertebral joint fusion cage combined with a local autograft and Group B, goats were implanted with a non-profile cage filled with a local autograft. The goats were prospectively evaluated for 24 weeks and then were sacrificed for evaluation. X-rays, CT and micro-CT scanning, and undecalcified bone histological analysis were used for the evaluation of fusion. RESULTS: 75.0% (9/12) of the goats in Group A were evaluated as having fusion at 12 weeks, compared to 41.7% (5/12) in Group B. 83.3% (10/12) of the goats in Group A were evaluated as having fusion at 24 weeks compared to 58.3% (7/12) in Group B. The fusion grading scores in Group A were significantly higher than that in Group B both at 12 weeks and 24 weeks (P < 0.05). Micro-CT scanning and undecalcified bone histological analysis showed that new bone formation can be obviously found in the bilateral uncovertebral joint. The bone volume fraction (BV/ TV) in Group A (23.59 ± 4.43%) was significantly higher than Group B (16.16 ± 4.21%), with P < 0.05. CONCLUSIONS: Preliminary results of this study demonstrated that uncovertebral joint fusion cage is effective for achieving early bone formation and fusion without increase of serious complications.

The Legend of the Luschka Tubercle and Its Association With Snapping Scapulae: Osseous Morphology of Snapping Scapulae on CT Images.

OBJECTIVE: The purpose of this article is to determine the osseous morphology of snapping scapulae on CT images. MATERIALS AND METHODS: Retrospectively, 2D and 3D CT images of the scapulae of 35 patients with snapping scapula were compared with 35 age-matched control group subjects. Two observers analyzed the following parameters: presence of the Luschka tubercle; abnormalities of the bones and periscapular soft tissues; shape, thickness, and length of the superior angle of the scapula; craniocaudal length of the scapula; minimum distance between the scapula and rib cage; depth of the subscapular fossa; and the superomedial angle. RESULTS: In patients with snapping scapulae, observer 1 did not find any Luschka tubercles, whereas observer 2 detected one; in the control group both observers found two Luschka tubercles (p > 0.49). One scapular osteochondroma was found in the group with snapping scapulae. No further abnormalities of the rib cage or periscapular soft tissues were found in that group. The superior angle of the scapula was significantly thicker in the snapping scapula group compared with the control group (4.8 ± 1.3 mm vs 4.0 ± 1.0 mm, p < 0.012). The subscapular fossa was significantly deeper in patients with snapping scapula than in control group subjects (25.7 ± 5.2 mm vs 21.8 ± 5.0 mm, p < 0.005). The remaining parameters did not differ significantly between the groups. CONCLUSION: The Luschka tubercle was rarely observed and not associated with a snapping scapula. However, the superior angle of the scapula was significantly thicker and the subscapular fossa was significantly deeper in patients with snapping scapula than in control group subjects.

Morphometry and microsurgical anatomy of Bochdalek's flower basket and the related structures of the cerebellopontine angle.

BACKGROUND: Bochdalek's flower basket (Bfb) is the distal part of the horizontal segment of the fourth ventricle's choroid plexus protruding through the lateral aperture (foramen of Luschka). The microsurgical anatomy of the cerebellopontine angle, fourth ventricle and its inner choroid plexus is well described in the literature, but only one radiological study has investigated the Bfb so far. The goal of the present study was to give an extensive morphometric analysis of the Bfb for the first time and discuss the surgically relevant anatomical aspects. METHOD: Forty-two formalin-fixed human brains (84 cerebellopontine angles) were involved in this study. Photomicrographs with scale bars were taken in every step of dissection to perform further measurements with Fiji software. The lengths and widths of the Bfb, rhomboid lip and lateral aperture of the fourth ventricle as well as the related neurovascular and arachnoid structures were measured. The areas of two sides were compared with paired t-tests using R software. Significance level was set at p < 0.05. RESULTS: Protruding choroid plexus was present in 77 cases (91.66%). In 6 cases (7.14%), the Bfb was totally covered by the rhomboid lip, and in one case (1.19%), it was absent. The mean width of the Bfb was 6.618 mm (2-14 mm), the mean height 5.658 mm (1.5-14 mm) and mean area 25.80 mm2 (3.07-109.83 mm2). There was no statistically significant difference between the two sides (p = 0.1744). The Bfb was in contact with 20 AICAs (23.80%), 6 PICAs (7.14%) and 39 vestibulocochlear nerves (46.42%). Arachnoid trabecules, connecting the lower cranial nerves to the Bfb or rhomboid lip, were found in 57 cases (67.85%). CONCLUSIONS: The Bfb is an important landmark during various surgical procedures. Detailed morphology, dimensions and relations to the surrounding neurovascular structures are described in this study. These data are essential for surgeons operating in this region.

Morphometric analysis of the uncinate processes of the cervical vertebrae.

BACKGROUND: Uncinate processes (UPs) are distinct features unique to cervical vertebrae. They are consistently found on posterolateral aspect of the superior end plate of 3rd to 7th cervical vertebrae. In this study, we investigated the morphology of the UPs with a particular emphasis on the regional anatomy and clinical significance. MATERIALS AND METHODS: The study included 63 vertebrae. The width, height and length of UPs were measured with a digital calliper. We also assessed inclination angle of UP relative to sagittal plane, angle between medial surface of UP and superior surface of vertebra, angle between long axis of the UP and frontal plane, angle between long axis of UP and sagittal plane. RESULTS: Average width of the UPs ranged from 4.25 mm at C3 to 6.33 mm at T1; average height ranged from 4.88 mm at T1 to 7.54 mm at C4; and average length ranged from 6.88 mm at T1 to 11.46 mm at C4. We measured the inclination angle of UP relative to sagittal plane, and found it to be relatively constant with T1 having the largest value. The average angle was 41.39°, and the range was 17° to 85°. The angle between the long axis of the UP and the sagittal plane was increasing signifi-cantly from C5 to T1. The average angle was 20.74° and the range was 6° to 65°. CONCLUSIONS: Anatomy of UPs is significant for surgeon who operates on the cervical spine. Hopefully, the information presented herein would decrease complications during surgical approaches to the cervical spine.

Biliary leakage from gallbladder bed after cholecystectomy: Luschka duct or hepaticocholecystic duct?

Anatomic variations in the biliary tract are common and can cause difficulties when a cholecystectomy is performed. One of the most common ones are hepaticocholecystic ducts and Luschka ducts, connecting the gallbladder or its bed to the bile ducts but distinction between these two types of ducts can be difficult. We do discuss here the differences between these anatomical variations, their origin and their clinical implications. These aberrant ducts may go unnoticed and may require further complementary procedures in case of postoperative biliary leakage. In addition to a careful surgical procedure and an examination of the cystic bed in the end of the intervention, an intraoperative cholangiography should be performed as often as possible.

Anatomy and clinical significance of the uncinate process and uncovertebral joint: A comprehensive review.

INTRODUCTION: The uncinate process and its associated uncovertebral articulation are features unique to the cervical spine. This review examines the morphology of these unique structures with particular emphasis on the regional anatomy, development and clinical significance. MATERIALS AND METHODS: Five electronic databases were utilized in the literature search and additional relevant citations were retrieved from the references. A total of 74 citations were included for review. RESULTS: This literature review found that the uncinate processes and uncovertebral articulations are rudimentary at birth and develop and evolve with age. With degeneration they become clinically apparent with compression of related structures; most importantly affecting the spinal nerve root and vertebral artery. The articulations have also been found to precipitate torticollis when edematous and be acutely damaged in severe head and neck injuries. The uncinate processes are also important in providing stability and guiding the motion of the cervical spine. CONCLUSION: This review is intended to re-examine an often overlooked region of the cervical spine as not only an interesting anatomical feature but also a clinically relevant one.

A rare case of bile leak due to type 2 duct of Luschka injury post open cholecystectomy: a case report.

Bile leak is an uncommon complication post cholecystectomy. The bile may originate from the cystic duct stump and less commonly from the aberrant ducts of Luschka. Such complications may occur when anatomical variations in the biliary tree go unnoticed. This case report presents a 24-year-old otherwise healthy female who presented with abdominal pain and distension that began 3 days after she underwent open cholecystectomy for symptomatic cholelithiasis. Imaging revealed choledocholelithiasis in the distal common bile duct, and free intrabdominal fluid collection. Endoscopic retrograde cholangiopancreatography done showed contrast leak from the duct of Luschka to the gall bladder bed. The biliary tree has many anatomic variations. These variations have clinical significance for surgical treatment of patients with biliary pathology. Surgeons should be aware of such variations to decrease the risk of bile leak post cholecystectomy.

Hepatobiliary-Specific MRI Contrast Agent Detection of Subvesical Duct (Luschka's) Injury Post-Laparoscopic Cholecystectomy: A Case Report.

Post-laparoscopic cholecystectomy bile duct injuries, especially involving Luschka's duct, are concerning. Biliary tree anomalies and the efficacy of intravenous administration of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in detecting bile leakage are reported based on a case. Teaching Point: Hepatobiliary-specific MRI-contrast agents prove valuable for noninvasive assessment of bile leakage after cholecystectomy.

Confronting the uncommon: Cholecystitis and cholangitis in a young adult arising from a bilobed gallbladder with subvesicle duct - A case report and review of literature.

INTRODUCTION AND IMPORTANCE: Bilobed gallbladder is a rare congenital anomaly characterized by the duplication of the gallbladder. It presents a unique challenge for surgeons due to its infrequency and the potential for perioperative complications. Anatomical variations, including the presence of the subvesicle duct of Luschka, should be suspected in these cases. CASE PRESENTATION: In our case report, we present the clinical details of a **23-year-old male** who presented with symptoms of acute cholecystitis and cholangitis. Preoperative imaging revealed a bilobed gallbladder, and incidentally, intraoperative evidence of the subvesicle duct/duct of Luschka was also observed during a successful laparoscopic cholecystectomy. Importantly, the patient experienced no postoperative complications. CLINICAL DISCUSSION: This case highlights considering bilobed gallbladder as a differential diagnosis in patients with cholecystitis or cholangitis is crucial. Surgeons should be vigilant about this anomaly when evaluating patients with gallbladder-related symptoms. CONCLUSION: We understand precise imaging plays a pivotal role in guiding surgical planning. Detecting bilobed gallbladder preoperatively allows for better assessment of biliary structures and helps prevent bile leaks during surgery. Although rare, awareness of bilobed gallbladder and its associated anatomical variants is essential for optimal patient management and successful surgical outcomes. Surgeons should remain attentive to such anomalies to ensure safe and effective procedures.

Duct of Luschka diagnosed by sonography in a patient with bile duct carcinoma and intrahepatic bile duct dilatation.

The bile duct of Luschka (BDL) is an anatomic anomaly that is an important cause of bile leakage after bile duct surgery. We report a case of bile duct carcinoma with dilated BDL that was diagnosed by ultrasonography (US). An 83-year-old man presented with an obstructive jaundice. US on admission revealed the presence of a solid hypoechoic mass in the bile duct at the hepatic duct confluence and a branch of the bile duct, about 2-4 mm in diameter, distinct from the dilated right anterior hepatic duct slightly upstream of the tumor. This branch had a spiral structure, extended along the gallbladder bed on the surface of segment 5 (S5) of the liver, and emanated small branches that entered the hepatic parenchyma. There has been no previous report of delineation of BDL by preoperative US.

Cerebellopontine angle meningioma originating from choroid plexus of the foramen of Luschka: An extremely rare entity and overlook of literature.

INTRODUCTION AND IMPORTANCE: Meningiomas without dural attachments are quite a novelty, with such meningiomas in the posterior fossa being even more far and few between. The authors describe an extremely rare cerebellopontine angle (CPA) meningioma lacking a dural attachment arising from the choroid plexus of the foramen of Luschka (CPFOL). CASE PRESENTATION: A 35-year-old male presented to our center complaining of a generalized and progressive headache for 10 months. A 3 cm × 4 cm well-defined lesion in the left CPA, hypointense in T1 and hyperintense in T2-weighted magnetic resonance imaging (MRI), was noted with no evident dural base or dural attachment. CPFOL was appreciated right at the point where the tumoral base was detected, which implied that the tumor originated from CPFOL. A gross total resection (GTR) was achieved, with the postoperative period remaining uneventful. The histopathologic investigation confirmed a transitional meningioma World Health Organization (WHO) grade I with no atypical features. CLINICAL DISCUSSION: Meningioma without dural attachment remains a rare phenomenon, with few available in English literature, and such pathology in the posterior fossa is even more unusual. Discriminating between CPFOL and another kind of CPA meningioma is mandatory when dealing with intracranial meningioma surgeries. CONCLUSION: While managing a space-occupying lesion around CPA, although extremely rare, a meningioma originating from CPFOL is suggested to be included in the differentials with necessary imaging analysis and advised to be imperatively pursued before proceeding for surgical intervention.

Bile Leakage From the Luschka Duct After Laparoscopic Sleeve Gastrectomy and Cholecystectomy: A Case Report.

Bile leakage may develop as a result of traumatic or iatrogenic injuries of bile ducts during laparoscopic cholecystectomy (LC). The frequency of Luschka duct injuries during LC is extremely rare. In this case, we present a case of bile leakage due to Luschka duct injury during sleeve gastrectomy (SG) and LC. The leakage was not noticed during the surgery, and on postoperative day 2, bilious drainage was seen from the drain. Magnetic resonance imaging (MRI) was helpful to determine Luschka duct injury. Biliary leakage resolved after endoscopic retrograde cholangiopancreatography (ERCP) with stent placement.

Identification and management of subvesical bile duct leakage after laparoscopic cholecystectomy: A systematic review.

Bile leak is a rare complication after Laparoscopic Cholecystectomy. Subvesical bile duct (SVBD) injury is the second cause of minor bile leak, following the unsuccessful clipping of the cystic duct stump. The aim of this study is to pool available data on this type of biliary tree anatomical variation to summarize incidence of injury, methods used to diagnose and treat SVBD leaks after LC. Articles published between 1985 and 2021 describing SVBD evidence in patients operated on LC for gallstone disease, were included. Data were divided into two groups based on the intra or post-operative evidence of bile leak from SVBD after surgery. This systematic report includes 68 articles for a total of 231 patients. A total of 195 patients with symptomatic postoperative bile leak are included in Group 1, while Group 2 includes 36 patients describing SVBD visualized and managed during LC. Outcomes of interest were diagnosis, clinical presentation, treatment, and outcomes. The management of minor bile leak is controversial. In most of cases diagnosed postoperatevely, Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is the best way to treat this complication. Surgery should be considered when endoscopic or radiological approaches are not resolutive.

Unveiling the Hidden Culprit: A Case of Bile Leakage Post-Cholecystectomy Caused by a Luschka Duct.

Teaching Point: Recognize anatomical bile duct anomalies as a potential etiology of bile leakage post-cholecystectomy, and emphasize the importance of adequate radiological evaluation for correct management.

Computed Tomography Osteoabsorptiometry Evaluation of Cervical Endplate Subchondral Bone Mineral Density.

STUDY DESIGN: Basic Science. OBJECTIVE: Poor subchondral bone mineral density (sBMD) has been linked with subsidence of cervical interbody devices or grafts, which are traditionally placed centrally on the endplates. Considering that sBMD reflects long-term stress distributions, we hypothesize that the cervical uncovertebral joints are denser than the central endplate region. This study sought to investigate density distributions using computed tomography osteoabsorptiometry (CT-OAM). METHODS: Twelve human cervical spines from C3-C7 (60 vertebrae, 120 endplates) were imaged with CT and segmented to create 3D reconstructions. The superior and inferior endplates were isolated, and the sBMD of the whole endplate, endplate center, and uncus was evaluated using CT-OAM. Density distributions were compared across the subaxial cervical spine. RESULTS: The uncinate region of the inferior and superior endplates was significantly denser than the central endplate across all vertebral levels (P < .01). When comparing sBMD of the whole inferior and superior endplates, the superior endplate was significantly denser than the inferior endplate (P < .0001). However, the inferior uncus was denser than the superior uncus (P = .035). When assessing sBMD by vertebral level, peak densities were observed at C4 and C5, while C7 was, on average, significantly less dense than all other vertebrae. CONCLUSION: The subchondral bone of the cervical uncovertebral joints is significantly denser than the central endplates. While the superior endplate in its entirety is denser than the inferior endplate, the inverse was true for the uncovertebral joints. This study serves as a basis for future investigations of new implant designs and their implications on subsidence.

Bile Leak Due to Luschka Duct Injury After Laparoscopic Cholecystectomy: A Case Report.

Bile leak is a common complication after laparoscopic cholecystectomy. Anatomical variations in the biliary tree can go unnoticed by the surgical team and cause complications such as this. This case report presents a patient admitted to the emergency department a week after a laparoscopic cholecystectomy due to abdominal pain and nausea. After a computed tomography, the patient was brought to the operating room for an exploratory laparoscopy, where an injured Luschka duct was found. The biliary tree has many variations that the surgeon should be aware of to minimize the risk of complications of this nature after laparoscopic cholecystectomy. There are imagining techniques with various grades of effectiveness, but in the end, the surgeon's expertise and experience are the main factors in avoiding these complications.

Meningioma Originating From Choroid Plexus of Foramen of Luschka: A Rare Case Report and Tip of Differential Diagnosis.

Meningiomas are the most common benign brain tumors, and most of them originate from the dura mater. However, in some cases, they can originate from the choroid plexus, and they are rarely found in the posterior cranial fossa. A 63-year-old female patient presented with dizziness and swallowing difficulty and was found to have a homogeneously enhancing mass in the right posterior cranial fossa. Mass removal was performed through retrosigmoid suboccipital craniotomy, and the mass was confirmed to originate from the choroid plexus. The pathological diagnosis was meningothelial meningioma. The patient had temporary swallowing difficulty but recovered without any neurological sequelae. We report a rare case of a lower cerebellopontine angle meningioma without dural attachment originating from the choroid plexus of the foramen of Luschka.

Magnetic Resonance Imaging of Unusual Neoplasms Related to Foramen of Luschka: A Review for Differential Diagnosis.

There are many types of neoplasms in or around the foramen of Luschka (FL), and definitive diagnosis in some cases requires knowledge of imaging findings. The uncommon and challenging neoplasms with FL involvement considered in this study are exophytic brainstem glioma, primary glioblastoma of the cerebellopontine angle (CPA), primary anaplastic ependymoma of the CPA, choroid plexus papilloma of the FL, solitary FL choroid plexus metastasis, extraskeletal myxoid chondrosarcoma of the jugular foramen, paraganglioma of the jugular foramen, exostosis of the jugular foramen, psammomatous meningioma in the lateral cerebellar medullary cistern, epidermoid tumor of the fourth ventricle, and a hypoglossal schwannoma. These neoplasms may have overlapping clinical and imaging features, but some have relatively distinct imaging features. Knowledge of the key clinical and magnetic resonance imaging features of these unusual lesions with FL involvement is important for radiologists to improve diagnostic ability and to assist the referring physician in the appropriate management of the patient.