SEARCH · PubMed Health

Results for “Anatomic Variation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources

PubMed2000

Our experience with surgical dissection of the facial nerve in parotid gland tumours. (A preliminary report).

Conservative parotidectomy is a primary method in the surgical treatment of parotid gland tumours. The classic parotid gland surgery uses the styloid process as a landmark for dissection of the facial nerve. The anatomical variations of the styloid process, however, prevent it from being always used as a reference landmark in this operative approach. This requires finding reliable invariable anatomical landmarks to be applied in the facial nerve dissection. The author presents his experience from the surgical treatment of 37 patients (25 females and 12 males) with tumours of the parotid gland. Adenoma was verified in 31 patients and 6 patients had a low malignancy carcinoma stage I. The mean age of the patients was 52 +/- 2.4 years. Conservative parotidectomy was performed in 28 patients (75.67%) and lateral parotidectomy in 9 patients (24.32%). The insertion of the posterior belly of digastric muscle on the mastoid process and tympanomastoid fissure were the primary landmarks used in the conservative parotidectomy. The proposed surgical technique was assessed as more reliable and less traumatic. Transient paralysis of the facial nerve occurred in 7 patients (18.9%) and subsided without treatment within 6-8 months. Based on his experience the author finds these anatomical landmarks easily recognizable and reliable start-points in facial nerve dissection that reduce the risk of traumatic injury of the facial nerve.

Adenoma↗

PubMed2003

[Occipital sinus as a potential differential diagnosis in patients suspect of dural sinus thrombosis--a case report].

INTRODUCTIONS: The diagnosis of dural sinus thrombosis despite of using modern imaging techniques still remains a difficult problem. For satisfactory interpretation of CT and MR scans it is indispensably important the knowledge of anatomical variations and possible imaging artifacts. One of the relatively rare developmental variations--giving chance for making false positive diagnosis--is the occipital sinus with hypoplasia or agenesis of transverse sinus. CASE REPORTS CONCLUSION: The incidence, the anatomical classification, the importance and the possibility of differentiation from sinus thrombosis are reviewed based on case reports of four patients.

Adult↗

PubMed2005

Atypical course of nervus axillaris.

OBJECTIVES: Aberrations observed during surgical therapy has inspired us to investigate the variations of nervus axillaris formation. MATERIAL: 100 brachial plexuses in 50 cadavers were examined for the incidence the variations of nervus axillaris. RESULTS: In 1 case (2%) we observed the aberration of nervus axillaris formation. CONCLUSION: This study identifies and describes an exceptional anatomical variation--beginning n. axillaris as the continuance of the posterior branch of the upper trunk (Fig. 1, Ref. 2).

Arm↗

PubMed2005

Ethnic variation in sinonasal anatomy on CT-scanning.

Computed tomography (CT) scanning of the paranasal sinuses provides valuable information in assessing extent of disease and fine detailed anatomy prior to endoscopic sinus surgery. Awareness of the different anatomic variants of the bony sinonasal anatomy will help the rhinologic surgeon's orientation during the procedure. We conducted a study to look at the incidence of the anatomic variation within the lateral wall of the nose and sinuses and to determine if there is any ethnic difference in these variants between a cohort of 100 Caucasian patients undergoing endoscopic sinus surgery in London and 100 Chinese patients treated in Hong Kong. We compared the two groups with chi-square test and the significant areas are those with p value of less than 0.05. The results show a higher incidence of pneumatisation of the middle turbinate (concha bullosa) and paradoxical bending of the middle turbinate in the Caucasian population. The infraorbital and suprabullar cell development was greater in the Caucasian population though the incidence of sphenoethmoidal cells was much greater in the Chinese population. When asymmetry of the anterior ethmoidal roof was considered, the left was consistently the highest in both groups, though there was no difference in the depth of the cribiform niche between right and left or between Caucasian and Chinese. The incidence of bent uncinate process and of complete absence of a sinus was higher in the Chinese population. There was no difference in the presence of pneumatisation of the agger nasi, of the uncinate process, or of the anterior clinoid process. There was no difference in the presence of septation adjoining the carotid in the lateral wall of sphenoid or in the exposure of the optic nerve within sphenoid or posterior ethmoid sinuses. Although there is no evidence that variants of the sinonasal anatomy seen on CT Scan have a causative effect in the disease process; a knowledge of their presence is paramount in minimising the potential for surgical complications.

Adolescent↗

PubMed2003

Preoperative assessment of anterolateral thigh flap cutaneous perforators by colour Doppler flowmetry.

An anterolateral thigh flap is very useful in head and neck reconstruction because of its long and large-caliber vascular pedicle, large skin territory and elevation simultaneous with tumour resection. However, the number and locations of cutaneous perforators vary individually, and thus, it is not widely used because flap elevation is often complicated and time-consuming owing to unexpected anatomical variations. To overcome this disadvantage, we assessed the number and locations of cutaneous perforators preoperatively by colour Doppler flowmetry. These data were compared with the intraoperative anatomical findings and their reliability evaluated. A total of 48 cutaneous perforators were found by preoperative colour Doppler flowmetry scanning of 17 anterolateral thigh flaps. All the perforators except two were found intraoperatively. Doppler scanning failed to detect four perforators. Colour Doppler flowmetry assessment therefore has a 92% true-positive rate and a 95.8% positive predictive value. All the flaps except one included multiple perforators, and sufficient blood circulation was observed in all cases. No flaps were unexpectedly changed to anteromedial thigh flaps or contralateral anterolateral thigh flaps because of inappropriate cutaneous perforators or the absence of perforators. Though this investigation is relatively time-consuming (30-40 min) and requires skill, it is very useful for preoperative flap planning and increases the reliability and safety of elevating an anterolateral thigh flap.

Adult↗

PubMed2004

Use of optical coherence tomography in delineating airways microstructure: comparison of OCT images to histopathological sections.

An ideal diagnostic system for the human airways should be able to detect and define early development of premalignant pathological lesions, to facilitate optimal curative treatment and prevent irreversible and/or invasive lung disease. There is great need for exploration of safe, repeatable imaging techniques which can run at real-time and with high spatial resolution. In this study, optical coherence tomography (OCT) was utilized to acquire cross-sectional images of upper and lower airways using fresh pig lung resections as a model system. Obtained OCT images were compared with parallel tissue characterization by conventional histological analysis. Our objective was to determine whether OCT differentiates the composite structural layers and inherent anatomical variations along different airway locations. The data show that OCT can clearly display the multilayered structure of the airways. The subtle architectural differences in three separate anatomical locations including trachea, main bronchus and tertiary bronchus were clearly delineated. Images of the appropriate anatomical profiles, with depth of up to 2 mm and 10 microm spatial resolution were obtained by our current OCT system, which was sufficient for recognition of the epithelium, subepithelial tissues and cartilage. In addition, the relative thickness of individual structural components was accurately reflected and comparable to histological sections. These data support OCT as a highly feasible, optical biopsy tool, which merits further exploration for early diagnosis of human airway epithelial pathology.

Animals↗

PubMedDate not supplied

Lateral condyle fractures in children: evaluation of classification and treatment.

OBJECTIVE: To compare intra-operative findings of fractures of the lateral condyle of the humerus in children with existing pre-operative radiographic classification. DESIGN: Prospective, consecutive. SETTING: Large urban hospital. PATIENTS: 25 consecutive displaced lateral condyle (humerus fractures) in 25 children diagnosed on biplanar radiographs. INTERVENTION: Open reduction and internal fixation through a lateral approach to the elbow. MAIN OUTCOME MEASUREMENTS: Anatomic variations of the lateral condyle of the distal humerus based upon intra-operative observations; comparison of findings with pre-operative radiographic classification. RESULTS: Three anatomic types were identified: 1) nine fractures exited on the medial side of the capitellum in the capitello-trochlear groove (36%), 2) eleven fractures exited beyond the capitello-trochlear groove through the trochlear epiphysis (44%), and 3) five fractures extended across the physis medially (20%). No fracture appeared to transverse the ossified portion of the capitellum (Milch Type I). The Milch anatomic classification was found to be inaccurate in 52% of the fractures. CONCLUSION: Intraoperative findings did not correlate with the presumed preoperative radiographic diagnosis in the majority of cases. A heightened awareness of the limitations of this traditional classification system is required for operative decision.

Child↗

PubMed2005

A morphometric study and variations on the lumbar arteries of human fetuses.

Lumbar arteries are in series with the posterior intercostal arteries. The aim of this study has been to investigate the morphometric data on the abdominal aorta of the human fetus and define different types of origin variations of the lumbar artery. Initially, the latex solution colored with red ink was injected into the thoracic aorta. The abdominal aorta and its branches were dissected and examined bilaterally in 120 fetuses (ranging between 16 and 32 post-menstrual weeks) and the anatomic variations recorded. Fourteen fetuses with variations were studied and photographed. The origins and morphologic variations of the lumbar arteries were defined and classified. The morphological relationship of the lumbar arteries to the abdominal aorta and the length and width (diameter) of the vessels were investigated by performing measurements using a digital calliper (mm). The frequency and the types of the different variations determined in the present study have been listed. Abdominal aortic branches and Lumbar artery aneurysms are rare lesions with potentially life-threatening consequences and they are difficult to access anatomically and formidable to manage operatively. During the performance of conventional or open surgical replacement of an abdominal aortic aneurysm with prosthetic grafts, the surgeon needs precise knowledge of the anatomy of the abdominal aortic branches and immediate retroperitoneal structures. The variations on the lumbar arteries may have clinical importance. When this region is under diagnostic and/or surgical investigation using computed tomography scan or diagnostic angiography, the possibility of these variations should be take into consideration to avoid complications.

Aorta, Abdominal↗

PubMedDate not supplied

The low skull base: an invitation to disaster.

BACKGROUND: Knowledge of anatomy including variations observed with endoscopy or computerized tomography scan is vital to the performance of safe endoscopic sinus surgery. The lower-than-normal skull base/cribriform plate is an anatomic variation, which if not noted preoperatively, can lead to entrance into the brain causing major injury. METHODS: Four case studies of chronic rhinosinusitis are reviewed in which either the whole anterior skull base or the cribriform plate is lower than usual and major complications occurred. RESULTS: All four cases had unilateral or bilateral entrance into the skull base/cribriform plate of the brain in the biopsy specimen, postoperative cerebrospinal fluid leak, and/or brain hemorrhage. One patient died from the injury, three patients had marked neurological sequelae. The low skull base and its meaning for the surgeon is discussed at length. CONCLUSION: The preoperative anatomy as determined by endoscopy and computerized tomography scanning has to be identified. Variations or abnormalities should be noted and taken into consideration for preoperative and operative planning. Failure to note skull base or cribriform anatomy variations may lead to brain entrance, injury, and death.

Adult↗

PubMed2004

The cystic artery in human foetuses.

The cystic artery varies in origin, course and number and it is important to recognise it during operative procedure. Insufficient recognition of its anatomical variation may contribute to a dangerous situation, especially during laparoscopic cholecystectomy. To prevent iatrogenic injuries of the vessels and bile ducts, correct preparation with clear identification of the anatomic structures is essential. Special attention must be given to the course of the cystic artery through the hepato-billiary triangle (Calot's triangle). The assumption of the present study was recognition of the vasculature of the gallbladder in human foetuses. The purpose of this investigation was to determine the origin of the cystic artery and its relation to Calot's triangle. In this study the cystic artery was most often (97.06%) a single vessel and only in one case (2.94%) was it a double vessel. It arose most often (82.34%) from the right proper hepatic artery, rarely from its trunk (8.82%) or its left branch (5.88%) and most rarely (2.94%) from the gastroduodenal artery. In all but one case the cystic artery coursed within Calot's triangle. Its exceptional course out of Calot's triangle concerned a cystic artery originating from the gastroduodenal artery (2.94%). The cystic artery most frequently (67.66%) runs behind the common hepatic duct, rarely (29.40%) over the common hepatic duct and most rarely (2.94%) on the left side of the cystic duct. In the material examined the cystic artery was not observed running in front of the common hepatic duct. The short type of cystic artery trunk (52.93%) was observed more frequently than the long one (44.13%).

Fetus↗

PubMed2003

Persistent left superior vena cava and central venous catheter position: clinical impact illustrated by four cases.

Variations in the course of the blood vessels are often incidental findings during clinical examination. A persistent left superior vena cava (LSVC) is really not rare (healthy individuals, 0.3-0.5%; patients with congenital heart disease, 4%) and serious complications have been described during catheterization in adults with LSVC (shock, cardiac arrest, angina). Therefore variations of the superior vena cava should be considered, especially when central venous catheterization via the subclavian or internal jugular vein is difficult. We describe the embryogenesis and the anatomic variations of persistent LSVC. Subsequently we suggest a classification of superior vena cava according to the positioning of a central venous catheter on the chest radiograph: type I, normal anatomy; type II, only persistent left superior vena cava; type IIIa, right and left superior vena cava with connection; type IIIb, right and left superior vena cava without connection. This classification is illustrated by four clinical cases.

Adult↗

PubMed1991

[Negligence of the physician's duty to care during "therapeutic local anesthesia"].

Therapeutic local anaesthesia, although a seemingly simple procedure, requires informed consent by the patient as well as proper indication and careful execution. Four cases selected from a medico-legal experience illustrate some severe complications. Nausea, dyspnoea and respiratory arrest (anaphylactic shock) occurred in a 34-year-old woman shortly after injection of 0.5% Bupivacaine into the paravertebral musculature for the treatment of acute neck pain. She had to be hospitalized for 18 days, at times requiring mechanical ventilation. Three other patients (women aged 40, 43 and 52 years, respectively) developed a pneumothorax after supposedly intramuscular injection of a local anaesthetic. They were hospitalized for 7 to 12 days for treatment by drainage. Anatomical variations were excluded by ultrasound in the 40- and 43-year-old patients. These case reports demonstrate that doctors performing such procedures do not always possess the necessary anatomical knowledge, and the possible occurrence of complications is underestimated.

Adult↗

PubMed1998

[Anatomic variants of the cystic duct and cysticohepatic junction: diagnosis with MR cholangiography].

The cystic duct are variable in length, course and site of termination. A knowledge of the variable anatomy of the cystic duct and cysticohepatic junction is important in biliary surgery, because failure to recognize anatomic variations may result in a significant ductal injury. Magnetic resonance cholangiography (MRC) is a recently developed technique that demonstrates the biliary tree noninvasively and without injection of contrast material. Anatomic variants of the cystic duct and cysticohepatic junction that may increase the risk of bile duct injury in biliary surgery are frequently identified with MRC. MRC will be a noninvasive and a useful technique in the diagnosis of anatomic variants of the cystic duct and cysticohepatic junction.

Cystic Duct↗

PubMed1995

Correlations between radial-maze learning and structural variations of septum and hippocampus in rodents.

Large, but non-pathological, individual differences in neuroanatomy of the brain exist in rodents, which have been shown to covary with behavioral traits. In the present review, we explore the relationship between variations in the extent of the intra- and infrapyramidal mossy fiber projection of the hippocampus and spatial and non-spatial learning capacities in mice and rats. Preliminary data concerning anatomical variation in the septo-hippocampal cholinergic system and its consequences for individual behavior are also presented. We conclude that the hippocampal intra- and infrapyramidal mossy fiber projection is intimately involved in the regulation of spatial, but not of non-spatial learning capabilities. Although lesion studies have shown that a well-functioning cholinergic system is a prerequisite for performance in spatial learning tasks, our preliminary data suggest that individual differences in the cholinergic system do not explain individual differences in learning.

Animals↗

PubMed2000

Coronary arteries from a single coronary ostium in the right coronary sinus: a previously unreported anatomy.

The coronary circulation originating from a single coronary ostium is rare. All possible anatomical variations were the basis of a recent classification. This case report describes a previously unreported IID(1) pattern, comprising a solitary coronary ostium in the right coronary sinus with an anatomical course of the right coronary artery. The left circumflex coronary artery arises from the proximal right coronary artery coursing behind the aorta to the left. The left anterior descending coronary artery arises from the proximal right coronary artery coursing to the left side anterior to the right ventricle.

Aortic Dissection↗

PubMed1999

Shoulder arthroplasty. Indications, contraindications and complications.

Prosthetic substitution of the glenohumeral joint, begun at the end of the last century, has developed greatly in recent years. Today the most widely used shoulder prostheses are defined as "modular" because of their extensive adaptability. The capacity to adapt to anatomic variations must be incorporated within their structure, and normal articular biomechanics must be respected. The choice of prosthesis must be based on the condition of the joint surfaces, on the anatomic and functional condition of the rotator cuff. So endoprosthesis of the shoulder is indicated for avascular necrosis of the head of the humerus, fractures and pseudoarthrosis of the extreme proximal end of the humerus, arthropathy following rotator cuff rupture. Total shoulder prosthetization is indicated for glenohumeral osteoarthritis, rheumatoid arthritis and outcomes of endoprosthesis. The principal contraindications for shoulder replacement include an infection in progress, Charcot's arthropathy and severe neurological pathologies. The complications of shoulder prostheses include infection, dislocation, loosening of a component, periprosthetic humeral and glenoid fractures, nerve injuries, fractures of a prosthetic component and ectopic ossification. At present prosthetic substitution of the glenohumeral joint offers good results. Indispensable conditions for these results include anatomic and functional integrity of the musculature, good bone quality, correct positioning of the prosthetic components and a proper rehabilitation program.

Arthroplasty, Replacement↗

PubMed1977

A criss-cross heart. Detailed anatomic description and discussion of morphogenesis.

Hearts with criss-cross atrioventricular connections are rare. Reports in the literature describe great anatomic variations with regard to the atrioventricular connections, spatial relationships of the ventricles, and connections and spatial relationships of the great arteries. In the example described in this report, the basic anatomic picture was that of transposition of the great arteries, but the criss-cross atrioventricular valves had resulted in atrioventricular discordance; hemodynamically, therefore, the situation resembled congenitally corrected transposition. One hypothesis for this anatomic configuration is that pronounced counterclockwise rotation (as viewed from below) brought the ventricular septum into a frontal plane and altered the respective positions of the pulmonary and aortic valves from those usually seen in congenitally corrected transposition and thereby resulted in crossed atrioventricular connections. An alternative hypothesis is that in this case one of the atrioventricular valves (the anteriorly positioned valve) may represent an anomalous communication that developed early in embryogenesis and connected the left atrial appendage to the right ventricular infundibulum.

Child↗

PubMed1993

Variations of the arterial anatomy of the foot.

Reconstruction of the arteries of the foot in patients with severe chronic arterial occlusive disease has become a routine and valuable procedure. However, it is frequently difficult to select the optimal site for the distal arterial anastomosis. In order to determine the most important anatomic variations of foot arteries and the relationship of the dorsalis pedis artery to crossing tendons, the following study was performed in 30 cadaver limbs of 17 persons (9 men and 8 women). Their mean age at death was 69.8 years (range: 42 to 93 years). Methods to evaluate anatomy included anatomic dissection, arteriography, and preparation of corrosion cast models. The latter was performed by injection of liquid plastic and catalyst into the tibial arteries followed by chemical débridement of the soft tissue of the foot. Photographs of the corrosion cast models were taken at various stages of soft tissue dissolution. The dorsalis pedis artery was absent in 6.7% of the cases, and the arcuate artery was absent in 33%. The dorsalis pedis artery arose from the peroneal artery in 6.7%. The dorsalis pedis artery crossed under the extensor hallucis longus tendon at the ankle in 54%, above the ankle in 43%, but below the ankle in only 3%. Our study suggests that the optimal site for the dorsalis pedis artery anastomosis on the foot is the segment distal to the ankle.

Adult↗