Focal compression of the upper left thoracic intersegmental arteries as a potential cause of spinal cord ischemia.

BACKGROUND AND PURPOSE: This study was prompted by recurrent angiographic observations of focal stenoses involving the proximal segment of the left upper thoracic intersegmental arteries, a few centimeters distal to their origin. The purpose was to investigate the nature and prevalence of this anomaly. MATERIALS AND METHODS: The existence of non-ostial thoracic intersegmental artery stenoses was evaluated in 50 angiograms; the contribution of stenosed branches to the anterior spinal artery was recorded. Angiograms performed in 3 patients with right-sided aortas were also reviewed. The topographic relationships of the upper thoracic intersegmental artery with surrounding structures were investigated in 3 cadavers. RESULTS: Thirty-seven non-ostial stenoses were found in 26 patients (52%), predominantly on the left side (92%), between T3 and T8, most frequently at T4 and T5 (54%). Severe lesions were observed in 10% of cases. Patients with stenoses had fewer detectable anterior radiculomedullary arteries between T3 and T5 (35% versus 54%). Upper intersegmental artery stenoses, documented on the left side of all 3 specimens, appeared to be caused by the recurrent path of these intersegmental arteries related to the leftward position of the thoracic aorta, and by their course around reinforced paramedian longitudinal strands of the endothoracic fascia. CONCLUSIONS: Upper thoracic intersegmental artery stenoses are frequent. They result from the leftward deviation of the descending aorta and the existence of a fixed point along the course of the intersegmental arteries related to the endothoracic fascia. Because contributors to the spinal vascularization often originate at similar levels, these stenoses may play a role in the susceptibility of the upper and midthoracic spinal cord to ischemia.

Injury to the axillary nerve after reverse shoulder arthroplasty: an anatomical study.

BACKGROUND: Subclinical neurological lesions after reverse shoulder arthroplasty are frequent, mainly those involving the axillary nerve. One of the major reported risk factors is postoperative lengthening of the arm. The purpose of this study was to evaluate the anatomical relationship between the axillary nerve and prosthetic components after reverse shoulder arthroplasty. The study hypothesis was that inferior overhang of the glenosphere relative to glenoid could put this nerve at risk. MATERIAL AND METHODS: Eleven fresh frozen shoulder specimens were dissected after having undergone reverse shoulder arthroplasty using a classic deltopectoral approach. RESULTS: The mean distance from the inferior border of the glenoid to the inferior edge of the glenosphere was 6.0±4.3mm (range, 1.0 to 16.2mm). The axillary nerve was never closer than 15mm to the glenosphere. The main anterior branch of the axillary nerve was in close contact with the posterior metaphysis or humeral prosthetic implant. The mean distance between the nerve and the humeral implants was 5.2±2.1mm (range, 2.0 to 8.1mm). CONCLUSIONS: The proximity of the axillary nerve to the posterior metaphysis or humeral implants may be a risk factor for axillary nerve injury after reverse shoulder arthroplasty. CLINICAL RELEVANCE: This study quantifies the proximity of the axillary nerve to the implant after reverse shoulder arthroplasty. LEVEL OF EVIDENCE: Basic science study, cadaver study.

A critical inventory of preoperative skull replicas.

INTRODUCTION: Physical replicas of organs are used increasingly for preoperative planning. The quality of these models is generally accepted by surgeons. In view of the strong trend towards minimally invasive and personalised surgery, however, the aim of this investigation was to assess qualitatively the accuracy of such replicas, using skull models as an example. METHODS: Skull imaging was acquired for three cadavers by computed tomography using clinical routine parameters. After digital three-dimensional (3D) reconstruction, physical replicas were produced by 3D printing. The facsimilia were analysed systematically and compared with the best gold standard possible: the macerated skull itself. RESULTS: The skull models were far from anatomically accurate. Non-conforming rendering was observed in particular for foramina, sutures, notches, fissures, grooves, channels, tuberosities, thin-walled structures, sharp peaks and crests, and teeth. CONCLUSIONS: Surgeons should be aware that preoperative models may not yet render the exact anatomy of the patient under consideration and are advised to continue relying, in specific conditions, on their own analysis of the native computed tomography or magnetic resonance imaging.

3D for D3: role of imaging for right colectomy in a case with congenital superior mesenteric vein aneurysm and co-existing anomalous irrigation.

BACKGROUND: The D3 right colectomy for cancer requires dissection in the vicinity of the superior mesenteric vessels, which requires preoperative 3D imaging in these patients. CASE REPORT: We present a patient with a caecum adenocarcinoma cancer which underwent D3 resection of the right colon, preceded by pre-operative MDCT with 2D multiplanar reconstruction and 3D volume rendering. RESULTS: The dataset analysis revealed a rare congenital aneurysm of the superior mesenteric vein below the spleno-mesenteric confluence and a co-existing anomalous irrigation in the form of an ileo-mesenteric trunk. The surgical procedure was carried out as planned and the patient presents no signs of recurrence of the disease one year after the intervention. CONCLUSIONS: The case presented - with a rare and complicated vascular situs - illustrates particularly well that multimodal post-processing of the CT dataset for volume rendering allows proper assessment of the arrangement of pertinent blood vessels, and, consequently in the planning, setup and accomplishing the delicate operation, avoiding the surgical pitfalls and iatrogenic injuries.

Gastric varices without portal hypertension: role of left inferior vena cava?

A variant vascular anatomy was detected during regular analysis of multidetector computed tomography angiography of the abdomen in a 70 year-old female patient, referred to the department of surgery for laparoscopic right colectomy for colon cancer. The anomalous vessel was located left to the aorta, and was consistent with a persistent left inferior vena cava. It was connected by two retroaortic rootlets to the dorsal surface of the regular right inferior vena cava and had four notable tributaries - an anastomosis with the iliolumbar trunk, ovarian vein, renal vein and the inferior phrenic vein. In the upper abdomen, the left inferior vena cava took a tortuous course, passing at first between the spleen and the diaphragm, then curving below the inferior splenic border and terminating in an irregular network in the posterior region of gastric fundus and cardia, close to the splenic hilum, without supradiaphragmatic continuation. Despite this extraordinary termination, there were no signs of portal hypertension or data on previous occurrence of this condition.

Unilateral hypoplasia of the rostral end of the superior sagittal sinus.

BACKGROUND AND PURPOSE: Hypoplasia of the rostral third of the SSS is a well-known variant and constitutes the most frequent variation of the SSS after preferential drainage to one of the transverse sinuses. Our aim was to describe unilateral hypoplasia of the rostral end of the SSS. MATERIALS AND METHODS: CTA performed in 100 consecutive patients studied for conditions other than dural sinus thrombosis was reviewed for the presence of a unilateral or bilateral hypoplastic rostral SSS. Associated dural venous sinus anomalies were recorded as well. The angiographic anatomy of unilateral hypoplastic rostral SSS was illustrated by 2 cases further imaged with DSA. RESULTS: Unilateral hypoplastic rostral SSS was found in 7 patients (7%). In all cases, compensatory drainage occurred through a large superior frontal vein that joined the SSS in the region of the coronal suture. Three of the 7 patients with a unilateral hypoplastic rostral SSS had at least another dural venous sinus anomaly. Complete or bilateral hypoplastic rostral SSS was noted in 3 patients (3%). CONCLUSIONS: Unilateral hypoplastic rostral SSS is more than twice as frequent as bilateral hypoplastic rostral SSS. It is the most frequently encountered variation of the SSS. Knowledge of this anatomic variation is important to avoid diagnostic pitfalls and to avoid erroneously mistaking it for a thrombosis. Four types of variations of the rostral SSS may be identified: 1) classic anatomy with a fully developed rostral SSS; 2) duplication of the rostral SSS; 3) complete or bilateral hypoplastic rostral SSS; 4) unilateral hypoplastic rostral SSS. The 4 types of rostral SSS variations can be explained by studying the embryologic development of the SSS.

Kaposi's sarcoma after repeated surgical procedures in an immunocompetent patient: the lymphatic hypothesis.

A 63-year-old Swiss patient developed acquired nodules on his right palm after 3 localized surgeries, called 'needle fasciotomy', for Dupuytren's disease. Kaposi's sarcoma (KS) was diagnosed in a biopsy of a nodule. A positive immunolabeling and serology for human herpesvirus 8 has been found, but human immunodeficiency virus and hepatitis C identification remained negative. The nodules were limited to the surgically traumatized area. This first report of a nonimmunocompromised patient developing a KS after repeated surgeries in a unique peculiar localized area with a dense lymphatic network sustains the hypothesis that tissue alterations involving the lymphatic system could play a central role in the occurrence of KS.

Arteria lusoria: developmental anatomy, clinical, radiological and surgical aspects.

The left aortic arch with an aberrant right subclavian artery, or arteria lusoria, is the most common aortic arch anomaly, occuring in 0.5-2.5% of individuals. Four vessels arise sequentially from the aortic arch: the right common carotid artery, the left common carotid artery, the left subclavian artery and the aberrant right subclavian artery, which crosses upwards and to the right in the posterior mediastinum. It results from a disruption in the complex remodelling of the paired branchial arches, typically of the right dorsal aorta distal to the sixth cervical intersegmental artery. The diagnosis and differentiation of arch anomalies is based on findings at chest radiography in association with those at esophagography. It is usually asymptomatic. When symptomatic, it produces dysphagia lusoria or dyspnea and chronic coughing. Treatment is indicated for symptomatic relief of dysphagia lusoria and for prevention of complications due to aneurysmal dilatation.

The risk of injury to neurovascular structures from distal locking screws of the Unreamed Humeral Nail (UHN): a cadaveric study.

When performing distal interlocking of an intramedullary humeral nail, there is risk of iatrogenic injuring to the neurovascular structures. Our cadaveric study with frozen sections through the distal humerus presents the anatomic relationship of the different neurovascular bundles and the trajectories used for the implantation of the three distal interlocking screws of the AO-UHN. The middle lateromedial pin was in direct contact with the radial nerve in 3 out of 10 cases, with the ulnar nerve in 3 out of 10 cases and with the brachial artery in 1 out of 10 cases. We recommend using only the two anteroposterior screws for distal interlocking, avoiding the lateromedial locking option. If this lateromedial locking screw is needed to gain adequate stability, it should be introduced under visual control.

Developmental anatomy of the distal vertebral artery in relationship to variants of the posterior and lateral spinal arterial systems.

BACKGROUND AND PURPOSE: A certain number of anatomic variants involving the distal vertebral artery (VA) are explained by variations in size and connection of the lateral spinal artery (LSA). This study examined the possible role of another branch of the VA, the posterior spinal artery (PSA), in the development of similar vascular variations. MATERIALS AND METHODS: Four types of variations in the distal VA, including the C1 and C2 origins of the posterior inferior cerebellar artery (PICA), the duplication of the distal VA, and the aberrant course of the distal VA, are illustrated by 9 angiographic observations. RESULTS: For each type of VA variant listed above, examples resulting from variations in size and connection of the LSA and PSA could be matched. CONCLUSION: Variation in size and connection of the PSA is at the origin of a set of anatomic variations of the distal VA similar, but not identical, to the vascular variants linked to the LSA.

Vascular invasion in pancreatic cancer: evaluation of endoscopic ultrasonography, computed tomography, ultrasonography, and angiography.

PRINCIPLES: Current methods for detecting vascular invasion in pancreatic cancer can be inaccurate, invasive, and expensive. The aim of this study is to assess the value of current imaging modalities in determining vascular invasion by pancreatic cancer. METHODS: The results of Endoscopic Ultrasonography (EUS), Computed Tomography (CT), Ultrasonography (US), and Angiography performed in 170 patients, suffering from pancreatic cancer, were retrospectively studied and correlated with intra-operative findings and surgical anatomopathological diagnosis after resection. We assessed sensitivity, specificity, positive and negative predictive values, and accuracy for detecting vascular invasion. RESULTS: EUS turned out to be the most reliable imaging technique for detecting vascular invasion in pancreatic cancer, with a sensitivity of 55%, specificity of 90%, positive predictive value of 61.1%, negative predictive value of 87.5%, and accuracy of 82.2%. CT results were 39.4%, 90%, 52%, 84.4%, and 79.1% for the respective categories, with however, better results with multislice CT. The US results were 3.7% for the sensitivity, 96.3% for the specificity, 25% for the positive predictive value, 75.2% for the negative predictive value, and 73.4% for the accuracy. For angiography, the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy were 52.6%, 72.3%, 43.5%, 79.1%, and 66.7% respectively. CONCLUSION: In this study, EUS was the most valuable imaging modality in assessing vascular invasion (especially for venous invasion) for pancreatic cancer, with an accuracy of more than 80%. A further prospective study should be carried out to evaluate the combination of imaging modalities for the detection of vascular involvement, especially with multi-slice CT which almost reached the performances obtained by EUS.

[Meaning of stylopharyngeal fascia in intraoral block techniques]. / Die Bedeutung der Fascia stylopharyngea bei intraoralen Blockadetechniken.

BACKGROUND: The almost unknown stylopharyngeal fascia may be one of the reasons for unsuccessful therapy of the trigeminal neuralgia by a transoral block of the superior ganglion of the sympathetic trunk. We investigated the anatomy of the fascia to show the efficiency of the block for this therapy. MATERIALS AND METHODS: 103 halves of human heads were investigated. The stylopharyngeal fascia was dissected by a lateral approach. We classified three groups. Group A was formed by fascias without perforation, group B by perforated fascias and group C by all halves without a developed fascia. RESULTS: We found a fully developed fascia in 86 cases. 13 halves had perforated fascias; in 4 cases the fascia was not developed. CONCLUSION: The stylopharyngeal fascia may inhibit the distribution of opoids into the infratemporal fossa associated with a consecutive block of the mandibular nerve and lower the rate of pain relief.

Anomalous intracranial drainage of the nasal mucosa: a vein of the foramen caecum?

The existence of the vein of the foramen caecum (VFC) in humans is still controversial. We present 2 patients with intracranial drainage of the nasal mucosa by a frontal cortical vein into a superior sagittal sinus, demonstrated by digital subtraction angiography. In both, the position of the intracranial passage was found to be slightly paramedian. An analogy to the VFC is made.

Anatomy of the anterior cruciate ligament.

The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. When the knee is extended, the ACL has a mean length of 32 mm and a width of 7-12 mm. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB). They are not isometric with the main change being lengthening of the AMB and shortening of the PLB during flexion. The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. The complex ultrastructural organization and abundant elastic system of the ACL allow it to withstand multiaxial stresses and varying tensile strains. The ACL is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the middle genicular artery.

[Sonography of the hand and wrist]. / Hand- und Handwurzel-Ultraschall.

In the recent years US has gained wide diffusion as a useful imaging tool in the evaluation of musculoskeletal disorders. Recognized advantages of US over the other imaging modalities are low costs, non-invasiveness, possibility to perform a dynamic examination and readiness. Unfortunately, US has a long learning curve and allows good results only when performed by well-trained and experienced examiners. Specifically, utilization of the recent small transducers allows to perform dynamic examination of the hand during flexion-extension movements of the fingers, while their high frequency (till 15 MHz) have increased the possibility to evaluate small anatomic structures of the hand and wrist as well as to detect subtle pathologic changes. The purpose of this article is to present first the normal basic anatomy and US appearance. Then the main pathological conditions including joint and tendon disorders, foreign bodies and other traumatic lesions, entrapment neuropathies and expansible lesions will be presented.

Human tibia bone marrow blood perfusion by non-invasive near infrared spectroscopy: a new tool for studies on microgravity.

Human tibia bone marrow (BM) and tibialis anterior muscle (TA) perfusion index (PI) was assessed non-invasively by near infrared spectroscopy. A decrease in the postis-chaemic reperfusion capability of the human tibia BM and TA muscle was observed for increasing age i.e., PI increases linearly as a function of age, starting from 30 years, both for BM (0.062 %/year, from -4.185 to -0.967 %/s) and TA muscle (0.046 %/year, from -5.760 to -3.883 %/s). The results define a "normal" baseline and demonstrate the sensitivity of the method to PI changes. The present technique should allow one to investigate physio-pathological effects induced by microgravity on tibia BM blood perfusion.

Anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbé: an angiographic study.

We studied the anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbé in 57 consecutive angiograms. Patients with pathology in intracranial venous structures or with inadequate image quality of the venous system were excluded. Arachnoid granulations were found in 12 of the 57 patients (21.1%), always at the junction of the vein of Labbé and the transverse sinus; the vein of Labbé was present in 55 patients (96.5%), most often without associated arachnoid granulations; the latter, however, were not observed in the absence of a vein of Labbé. This study confirms the close, constant anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbé. This observation may help to differentiate arachnoid granulations from pathologic conditions involving the transverse sinus such as dural sinus thrombosis. The constant character of this relationship suggests a developmental role of afferent veins in the formation of arachnoid granulations.

Endoscopic neck dissection in human cadavers.

OBJECTIVE: To evaluate the feasibility and efficacy of endoscopic neck dissection (END) in human cadavers. STUDY DESIGN: Experimental self-controlled study. METHODS: END on five human cadavers through three openings: one for the camera, one for the dissecting instrument, and one for a grasping one. The tissue specimens removed were divided into traditional neck groups (I to V). After the completion of END, open neck dissection was performed using standard surgical techniques and the remaining tissue within each neck group was retrieved. The important neck structures (carotid artery, internal jugular vein, cranial nerves X, XI, and XII, phrenic nerve) were evaluated for lesions. A pathologist evaluated each specimen, without knowing its exact origin in terms of neck group or side, and type of surgical technique used. For each specimen, the number of retrieved lymph nodes and their anatomic integrity was analyzed. RESULTS: Ten neck dissections were performed on 5 cadavers, without any major difficulty. An injury of the internal jugular vein occurred twice and once the phrenic nerve was cut. Little tissue was usually left for open surgical dissection. The average number of retrieved lymph nodes by endoscopy was 4.9 +/- 2.7 (mean +/- standard deviation). Completion open neck dissection retrieved an additional 0.5 +/- 0.5 lymph nodes. Efficacy of END was 92 +/- 10%. The majority of retrieved lymph nodes were intact but exhibited important postmortem autolysis artifacts. CONCLUSIONS: Endoscopic neck dissection is possible in human cadavers and is free of lesions to major structures. The majority of neck lymph nodes can be removed endoscopically.

Angiographic anatomy of the laterocavernous sinus.

BACKGROUND AND PURPOSE: The laterocavernous sinus (LCS) has recently been recognized as one of the major drainage pathways of the superficial middle cerebral vein (SMCV). Our purpose was to investigate the drainage pattern of the SMCV, with special emphasis on the angiographic anatomy of the LCS. METHODS: The drainage pathways of the SMCV were evaluated prospectively on 100 selective carotid angiograms obtained in 65 consecutive patients. RESULTS: The SMCV was absent in 19% of cases. A classic termination into the cavernous sinus (CS) was found in 20%, a paracavernous sinus in 39%, and an LCS in 22%. The LCS drained toward the pterygoid plexus (27%), the superior petrosal sinus (18%), the posterior aspect of the CS (32%), or a combination of these pathways (23%). A complete absence of connection between the LCS and CS was observed in 63.5% of the patients. CONCLUSION: The LCS is a laterosellar venous space that is anatomically and angiographically distinct from the CS. Secondary small anastomoses between the LCS and CS may make it difficult to differentiate the two structures. Appreciation of the course and connection pattern of the LCS is important, particularly when planning an endovascular approach to treatment of lesions in the region of the CS.