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PubMed2005

Major anatomical variations of the tracheobronchial tree: bronchoscopic observation.

Fiberoptic and rigid bronchoscopy are widely used diagnostic and therapeutic tools in pulmonary medicine. Investigators often neglect the bronchial variations; however, bronchial variations may have important implications for bronchoscopy, brachytherapy, pulmonary resections and intubations. It is accepted that anatomic variations of the airways are due to anomalies in the development of the lungs. As a result, lung buds grow to an inappropriate number or arise at atypical sites. In the present study, we tried to determine the incidence of bronchial variations in our region. We investigated 2550 consecutive reports of bronchoscopy retrospectively. Major variations of the tracheobronchial tree were found in 2.6% of patients examined by bronchoscopy. The most frequent finding was a bifurcate pattern in the right upper lobe (47.7%). The variations were localized to the right upper lobe in 71.6% of patients. Male predominance was observed in all anatomic variations except one.

Adolescent↗

PubMedDate not supplied

Anatomic variation in intrahepatic bile ducts: an analysis of intraoperative cholangiograms in 300 consecutive donors for living donor liver transplantation.

OBJECTIVE: To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. MATERIALS AND METHODS: The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. RESULTS: The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). CONCLUSION: The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%).

Bile Ducts, Intrahepatic↗

PubMed2006

The relationship of anatomic variation of pancreatic ductal system and pancreaticobiliary diseases.

The aims of this study were to identify the morphological diversities and anatomical variations of pancreatic ductal system and to define the relationships between pancreatic ductal systems, pancreaticobiliary diseases, and procedure- related complications, including post-ERCP pancreatitis. This study included 582 patients in whom both pancreatic duct (PD) and common bile duct were clearly visible by ERCP. PD systems were categorized into four types according to the relationship between common bile duct and PD. In types A and B, Wirsung duct formed the main PD. In type C, Wirsung duct did not form the main PD. If PD system did not fall into any of these three types, it was categorized as type D. The distribution of types among pancreatic ducts examined was as follows: type A: 491 cases (84.4%), type B: 56 cases (9.6%), type C: 20 cases (3.4%), and type D: 15 cases (2.6%). The anomalous anatomic variations of PD systems were divided into migration, fusion, and duplication anomalies. PD anomalies were noted in 51 patients, of which 19 (3.3%) were fusion anomalies (12 complete pancreas divisum, 7 incomplete pancreas divisum), and 32 (5.5%) were duplication anomalies (5 number variations, 27 form variations). No significant relationships between various PD morphologies and pancreaticobiliary diseases were found. However, post- ERCP hyperamylasemia was more frequently found in types C (41.7%), D (50%) and A (19.8%) than in type B (9.4%). In summary, whether Wirsung duct forms the main PD and the presence or absence of the opening of the Santorini duct are both important factors in determining the development of pancreatitis and hyperamylasemia after ERCP.

Bile Ducts↗

PubMed1995

Pancreatic development and anatomical variation.

The pancreas is formed by the fusion of the ventral and dorsal anlage, and a wide spectrum of anomalies or anatomical variations may appear related to this complicated process of fusion: e.g., agenesis, aplasia of a pancreatic anlage, hypoplasia, annular pancreas, pancreas divisum or nonfusion of the ventral and dorsal duct system, pancreaticobiliary maljunction, etc. Every endoscopist who engages in pancreatography or related diagnostic and therapeutic procedures should always be aware of all sorts of anatomical variations he or she might encounter.

Aged↗

PubMed2005

Anatomical variations of the flexor hallucis longus muscle and the consequences for tendon transfer. A cadaver study.

The aim of this study was to evaluate the occurrence of anatomical variations of the musculotendinous junction of the flexor hallucis longus muscle. Eighty cadaver specimens preserved according to Thiel's method were assessed. Following careful dissection, the distance between the musculotendinous junction and the bone-cartilage border of the distal tibia was determined. Three typical anatomical variations were found: (1) a long lateral and shorter medial muscle belly; (2) equal-length medial and lateral muscle bellies; (3) a long medial and shorter lateral muscle belly. As a special variation in two cases only one lateral muscle belly was found. When planning a flexor hallucis longus transfer, preoperative magnetic resonance tomography (MRT) should be carried out in order to guarantee sufficient coverage of an existing soft tissue defect. These anatomical characteristics have also to be considered when interpreting ultrasonic or MRT findings in this region.

Aged↗

PubMed2005

Anatomical variations of the supraorbital, infraorbital, and mental foramina related to gender and side.

PURPOSE: The aim of the study was to examine the different anatomical variations of the supraorbital, infraorbital, and mental foramina related to gender and side. MATERIALS AND METHODS: Measurements were made on 110 adult skulls without mandibles and isolated mandibles. Gender was determined for each skull. Parameters measured bilaterally included the distances from the supraorbital and mental foramina to midline, from the infraorbital foramen to the anterior nasal spine, from the infraorbital foramen to the inferior orbital rim, and from the mental foramen to the inferior rim of the mandible and the angle between the line linking the infraorbital foramen with the anterior nasal spine and horizontal plane. Comparisons were made between genders and sides and statistical analysis was done where appropriate using Student's t test. RESULTS: There were 70 male and 40 female crania. Nature of the 3 foramina was similar between sides and genders. The average distance from the left supraorbital foramen to midline in females was significantly lower than that in males (2.42+/-0.04 versus 2.56+/-0.05). The mean distances from the bilateral infraorbital foramina to anterior nasal spine in females were also significantly lower relative to those in males (3.28+/-0.03 versus 3.48+/-0.03 right and 3.31+/-0.03 versus 3.50+/-0.03 left). There were also considerable differences between sides in the average angle of the infraorbital foramen in both genders. CONCLUSIONS: Differences in several measurements suggest that gender and side should be considered when applying the anatomical variation data to an individual subject.

Adult↗

PubMed2002

Anatomic variations of the T2 nerve root (including the nerve of Kuntz) and their implications for sympathectomy.

OBJECTIVE: The aim of this study was to clarify the anatomic variations of the intrathoracic nerve of Kuntz, and this should help delineate the resection margins during video-assisted thoracic sympathectomy. METHODS: Sixty-six thoracic sympathetic chains of 39 adult Korean cadavers were dissected on both sides of the thorax in 27 cadavers (54 sides) and on one side in 12 cadavers (12 sides). RESULTS: The intrathoracic nerve was observed in 45 (68.2%) sides and was present bilaterally in 48.1% of cadavers. No intrathoracic nerve or ascending ramus communicans arising from the second thoracic nerve was observed in only 5 (7.6%) sides. The diameter of the intrathoracic nerve was 1.25 plus minus 0.55 mm on average. The arising point of the intrathoracic nerve from the second thoracic nerve was 7.3 mm on average from the sympathetic trunk. Presence of the stellate ganglion was noted in 56 (84.8%) sides, and 6 (9.1%) sides showed a single large ganglion formed by the stellate and the second thoracic sympathetic ganglia. The second thoracic sympathetic ganglion was most commonly located (50%) in the second intercostal space. CONCLUSION: The anatomic variations of the intrathoracic nerve of Kuntz and the second thoracic sympathetic ganglion were characterized in human cadavers. It is hoped that this study will help to improve the recurrence of symptoms caused by the intrathoracic nerve in an upper thoracic sympathectomy for hyperhidrosis.

Female↗

PubMed2003

Radiological evidence of anatomical variation of the inferior vena cava: report of two cases.

The inferior vena cava (IVC) is a retroperitoneal key structure whose location and integrity must be checked in every scan. A number of studies are reported in the literature concerning congenital variations of the inferior vena cava. Anatomical variations of this main venous trunk are relatively infrequent clinical findings during surgery or diagnostic procedures in patients without symptoms such as an aberrant venous drainage or abdominal pain. Among the other imaging techniques, computerized tomography is a non-invasive, effective technique for diagnosing diseases of the retroperitoneal space and, particularly, for detecting anomalies of the main vessels, such as the aorta or IVC, in asymptomatic patients. We present two cases of IVC variation as an incidental finding in patients studied by means of CT scan for the gradation of kidney carcinoma and pancreatic cancer respectively. Two different configurations of the system of the IVC (agenesis of the IVC with hypertrophy of the azygos vein and a double IVC respectively) were found in our cases. The embryological development of the IVC system is discussed, bearing in mind that knowledge of the different variations is important in order to avoid major surgical complications.

Adult↗

PubMedDate not supplied

[Angiographic characteristics of the internal thoracic artery--anatomic variations and their surgical importance].

INTRODUCTION: The internal thoracic artery is considered the graft of choice for surgical revascularization of the ischemic myocardium. The real incidence of anatomic variations of the internal thoracic artery is not known, although it is an extremely important issue, considering surgical strategy, as well as immediate and long-term outcome. MATERIAL AND METHODS: During a period of three months (Jun. 1st-Aug. 31st 1998) we have evaluated the left internal thoracic artery (ITA) in 80 randomly selected patients (62 men, average age being 57.4 +/- 5.2). RESULTS: Typical take-off, side branches, terminal division and absence of any atherosclerotic lesions were noted in 69 patients (86.25%). Angiographically apparent atherosclerotic lesions were not noted; anomalous take-off from the left subclavian artery was noted in 9 cases (11.25%--including one case of aneurysmatic proximal portion of the ITA); there were two cases where the lateral thoracic artery was present (2.5%) and three cases where the distal division was of a trifurcation type, which is not of surgical importance (3.75%). Average diameter of the left ITA was 2.19 +/- 0.24 mm for the entire group (2.20 +/- 0.19 mm for men, and 2.10 +/- 0.21 mm for women, p = NS). DISCUSSION: Results that we have obtained are in accordance with previously published data. We did not find significant (angiographically visible) atherosclerotic lesions of the ITA, however variations in the take-off and branching were found to be frequent (11.25%). Aneurysmatic left ITA is an extremely rare finding in the literature. Angiographically found variations (capable of causing coronary steal) are impossible to be detected during operation. This raises a question of a need for routine angiographic evaluation of the ITA before operation. For some patients, routine angiographic evaluation of the ITA before myocardial revascularization is mandatory: in pts with previous myocardial revascularization, in whom ITA was not used, but could have been damaged; in pts with atherosclerotic lesions of the supraaortic vessels; in pts with previous irradiation of the anterior mediastinum (ITA could be fibrotic); in pts with actual or corrected coarctation of aorta (ITA could be aneurysmatic). CONCLUSION: The incidence of anatomic variations of the ITA (that may be of surgical importance) is not negligible (13.25%). These data indicate that routine angiographic evaluation of the ITA should be considered in all patients in need for myocardial revascularization.

Aneurysm↗

PubMedDate not supplied

Anatomical variation of the tibial plafond: the anteromedial tibial notch.

An investigation of 77 intact foot and ankle specimens (21 fresh frozen and 62 preserved) was conducted to determine normal anatomical variation of the anteromedial region of the tibial plafond. Lower extremity specimens were obtained and carefully disarticulated at the ankle joint. Care was taken to observe anterior joint capsule attachments along with plafond surface anatomy. Specimens that exhibited signs of previous trauma or significant degenerative arthritic changes were not included in the study. All of the specimens were photographed with a millimeter scale, and the photographs were later evaluated to quantify anatomical variations of the anterior medial tibial plafond. The results of this investigation demonstrated a normal variant of articular notching of the anteromedial tibial plafond. The notching appears to function as a joint capsule anchor. In the more well developed notches, a fold, apparently of synovial tissue, was found. The notching increases the surface area for capsular attachment, is variable in size, and may assist in synovial fluid movement across the joint during ambulation. This articular notching, although often encountered arthroscopically, should be considered a normal anatomical variant unless localized degenerative processes are identified.

Aged↗

PubMed1985

Tympanoplasty in children and anatomical variations of the epipharynx.

Short-term results or post-operative check-ups after tympanoplasties in children and adults are compared. There is no higher incidence of recurrent perforations in children. The distribution of air cells in adults and children does not vary, indicating that anatomic variations, rather than disease, are responsible for the sclerosis in the mastoid. Anatomic variations of the epipharynx might influence ventilation. Correlations between the width of the epipharynx and the distance between molars and premolars are shown, as is an inverse relation between the height of the palate and the height of the septum. These observations might be important for a prognosis in patients with ear disease.

Adolescent↗

PubMed1977

Anatomical variations of the stylohyoid complex and their clinical significance.

Anatomical variations of the styloid process and its ligaments may be responsible in some patients for vague symptoms referrable to the throat and neck. On occasions, they result in some diagnostic and therapeutic quandaries. The anatomy is reviewed and five case reports used to illustrate typical and unusual problems.

Aged↗

PubMed2001

The role of the medial wall and its anatomical variations for bimanual antiphase and in-phase movements.

The medial wall of the frontal cortex is thought to play an important role for bimanual coordination. However, there is uncertainty regarding the exact neuroanatomical regions involved. We compared the activation patterns related to bimanual movements using functional magnetic resonance imaging in 12 healthy right-handed subjects, paying special attention to the anatomical variability of the frontal medial wall. The subjects performed unimanual right and left and bimanual antiphase and in-phase flexion and extension movements of the index finger. Activation of the right supplementary motor area (SMA) proper, right and left caudal cingulate motor area (CMA), and right and left premotor cortices was significantly stronger during bimanual antiphase than bimanual in-phase movements, indicating an important function of these areas with bimanual coordination. A frequent anatomical variation is the presence of the paracingulate sulcus (PCS), which might be an anatomical landmark to determine the location of activated areas. Seven subjects had a bilateral, three a unilateral right, and two a unilateral left PCS. Because the area around the PCS is functionally closer coupled to the CMA than to the SMA, activation found in the area around the PCS should be attributed to the CMA. With anatomical variations such as the presence of a PCS or a vertical branch of the cingulate sulcus, normalization and determination of the activation with the help of stereotaxic coordinates can cause an incorrect shift of CMA activation to the SMA. This might explain some of the discrepancies found in previous studies.

Adult↗

PubMed1993

Study of Circle of Willis in 1021 consecutive autopsies: incidence of aneurysms, anatomical variations and atherosclerosis.

Incidence of subarachnoid haemorrhage from aneurysmal rupture is very low in India when compared with that in the Western world and Japan. Either they are not recognised or diagnosed adequately or there may be a true decreased geographical/racial incidence. To have an idea of the true incidence of aneurysms, a study of Circle of Willis with its anatomical variations and incidence of atherosclerosis was carried out in 1021 consecutive autopsies. The incidence of anatomical variations was slightly less than that seen in most of the other studies. Atherosclerosis was seen in 9.2% of the Circles of Willis. There were only two aneurysms, both located at the bifurcation of middle cerebral artery. This incidence of 0.2% is definitely much lower than that seen in other series, thus, suggesting that the incidence of subarachnoid haemorrhage from aneurysmal rupture is likely to be genuinely less in India.

Adult↗

PubMedDate not supplied

Etiologic significance of anatomic variations in the main intrahepatic bile ducts in hepatolithiasis.

Abnormal union of intrahepatic bile ducts has been suggested as a possible etiologic factor in the occurrence of intrahepatic stones. A series of 241 patients were examined by direct cholangiography, and anatomic variations in the intrahepatic bile ducts were classified into four types: Type A-1, normal union having a true right hepatic duct; Type A-2, absence of a right hepatic duct, with a trifurcation; Type B, posterior segmental duct draining into left hepatic duct; Type C, anterior segmental duct draining into left hepatic duct. The most dominant type was Type A-1, which occurred in 58.3 to 66.0 per cent of the cases, followed by Type A-2 with 12.5 to 19.8 per cent. Type B showed the lowest incidence, occurring in 4.5 to 10.4 per cent. No statistical difference existed in the distribution of the type of union of intrahepatic bile ducts on the one hand and the presence or absence of intrahepatic stones on the other. Thus, anatomic variations in the main intrahepatic bile ducts do not seem to be associated with hepatolithiasis, and their etiologic significance seems to be unlikely.

Adult↗

PubMedDate not supplied

Anatomic variations of foramen ovale.

OBJECTIVES: Foramen ovale is of great surgical and diagnostic importance in procedures like percutaneous trigeminal rhizotomy for trigeminal neuralgia, transfacial fine needle aspiration technique in perineural spread of tumour and electroencephalographic analysis for seizure. This study presents the anatomic variations in dimensions, appearance and number of foramen ovale. METHODS: We studied 35 dried human skulls available in the Department of Anatomy, Manipal college of Medical Sciences, Pokhara, Nepal. Variations in appearance and number of foramen ovale were noted. Length and width of foramen ovale was measured. Comparison with other races and differences between right and left sides were also discussed. RESULTS: Out of 70 sides in 35 adult skulls, mean length and width of foramen ovale was 7.46+/-1.41 mm and 3.21+/-1.02 mm on right side and 7.01+/-1.41 mm and 3.29+/-0.85 mm on left side. Shape of foramen ovale was typically oval in 43, (22 on right, 21 on left) almond shape in 24 (Fig.1, arrowhead; 11 right, 13 left), round in 2(1 right, 1 left) and slit-like in 1(Fig.1, arrow). Bilateral oval foramen was observed in 15 and bilateral almond was in 7. Out of 70 sides in 35 adult skulls 3 (2 left, 1 right) sides had spine on the margin of the foramen (Fig.2, arrow), 3 (2 left, 1 right) had tubercle protruding from the margin (Fig. 3, arrow), 2 (1 left, 1 right) sides had bridge like bony spur dividing the foramen into two compartments(Fig. 2, arrowhead), 9 (5 left, 4 right) had bony plate on the margin of foramen ovale (Fig. 4, arrow). Variant foramen ovale was observed in 24.2%. CONCLUSION: Anatomical variations in size and shape of foramen ovale could be explained by developmental reasons. Considering the immense surgical and diagnostic importance of foramen ovale, this study was worthwhile.

Adult↗

PubMed2006

Para-cavernous sinus venous structures: anatomic variations and pathologic conditions evaluated on fat-suppressed 3D fast gradient-echo MR images.

BACKGROUND: The cavernous sinus communicates with several para-cavernous sinus venous structures, receiving blood flow from the superficial middle cerebral vein (SMCV), the sphenoparietal sinus (SPS), and the superior ophthalmic vein, and draining into the superior and inferior petrosal sinuses and pterygoid and basilar plexuses. Anatomic variations of these veins have been previously reported; however, some details, such as the relationship between the SPS and the SMCV, are incompletely characterized. The anatomic variations of para-cavernous sinus veins, especially drainage patterns of the SMCV, were evaluated on MR imaging. MATERIALS AND METHODS: Thirty-seven patients, including those without any lesions affecting the cavernous sinus or para-cavernous veins and patients with carotid cavernous fistulas, were examined by using fat-suppressed contrast-enhanced 3D fast gradient-echo MR imaging. Two neuroradiologists evaluated the images on a viewer, regarding the normal anatomy and the pathologic findings of the para-cavernous sinus veins. RESULTS: The fat-suppressed 3D fast gradient-echo MR images clearly depicted the para-cavernous sinus venous structures in all patients. SMCVs had 4 variations in the drainage patterns. The most frequent pattern was drainage into the SPS (39%), and other types were draining into cavernous sinus, pterygoid plexus, and tentorial sinus. The SPS had 3 variations. The most frequent pattern was drainage into cavernous sinus (72%), and others were the hypoplastic type or those draining into pterygoid plexus. CONCLUSION: The fat-suppressed 3D fast gradient-echo MR image is useful for evaluating the venous structures in the skull base. Knowledge of the variations is important for diagnosis and endovascular treatment of the cavernous sinus lesions.

Adult↗

PubMed1987

Canine AV nodal artery: anatomical variations and a detailed description of cannulation technique.

Cannulation of the atrioventricular (AV) nodal artery for selective perfusion of the AV node is a useful physiological method for evaluating the direct effects of pharmacological agents on the AV node. However, previous reports have not included a detailed description of the technique for AV nodal artery cannulation. Furthermore, successful cannulation is dependent on familiarity with the anatomical variations of the AV nodal artery [i.e., the most superior posterior septal artery (PSA)], which supplies blood to the AV nodal region and the posterior descending artery (PDA). The purpose of this report is to describe in detail the technique for cannulation of the AV nodal artery as well as the common anatomical variations of this artery. The anatomy of the PDA and PSA was studied at postmortem examination with ink injection in 30 dogs. Verification of the anatomical location of the AV nodal artery was aided by the induction of transient AV nodal conduction block following intracoronary administration of acetylcholine in the beating heart, as was done in previous studies. Two main variations and two subtypes of PDA anatomy and three main variations of AV nodal artery were found. Based on the present findings, an improved technique for cannulation of the AV nodal artery was established. Using this technique, we achieved a high rate of successful cannulation.

Animals↗