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PubMed1996

Variability of femoral muscle attachments.

Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

Aged↗

PubMed2003

[Anatomical study and three dimensional image characteristic analysis of basicranial artery and its clinical significance].

OBJECTIVE: To observe and measure the inside diameter of basicranial arteries, the angulation of main arteries, the three dimensional image characteristic of internal carotid arteries and the anatomical variation of Willis circle. METHODS: The arteries of 30 formalin-fixed adult heads were injected with latex after which the caliber and characteristic of cerebral arteries were observed and measured. The three dimensional image characteristic of internal carotid arteries and its branches were measured using 3D-DSA. RESULTS: (1) Main artery caliber: origin of internal carotid artery (Left 5.12 +/- 1.48 mm; Right 5.11 +/- 1.42 mm); origin of middle cerebral artery (Left 2.93 +/- 1.44 mm; Right 2.92 +/- 1.46 mm); origin of anterior cerebral artery (Left 2.63 +/- 1.33 mm; Right 2.61 +/- 1.32 mm); origin of vertebral artery (Left 4.37 +/- 1.21 mm; Right 3.22 +/- 1.64 mm); origin of basilar artery (4.45 +/- 1.28 mm); origin of posterior cerebral artery (Left 2.62 +/- 1.36 mm; Right 2.61 +/- 1.22 mm). (2) The angulation of main arteries: C1, 2 of ICA and C4, 5 of ICA (Left 32 +/- 22 degrees; Right 36 +/- 28 degrees ); ICA and ACA (Left 43 +/- 26 degrees; Right 46 +/- 28 degrees). (3) The results show that anatomical and three dimensional image characteristic of internal carotid arteries have no difference (P > 0.05). (4) The anatomical variation of Willis circle: Type O (56.7%); Type A (16.7%); Type P (20.0%); Type AP (6.7%). CONCLUSIONS: It is helpful to measure the inside diameter of basicranial arteries for the selection of various catheter in interventional neuroradiology, to observe the angulation of main arteries and the three dimensional image characteristic of internal carotid arteries for the moulding of various catheter in endovascular therapy and to master the anatomical variation of Willis circle for decreasing complications of endovascular treatment and judging prognosis of cerebrovascular diseases.

Adult↗

PubMed1991

[X-ray computed tomographic study of the ethmoid and middle meatus. II. Radio-anatomy (axial incidence) and morphological variations].

Chronic rhinosinusitis endoscopic surgery needs an accurate evaluation of diseases and paranasal sinus anatomic variations. High resolution CT by thin section (2 mm) allow this pre-operative assessment. An anatomical study of the ethmoid air cell system is always possible in axial plane. The bidimensional CT exploration (axial and coronal plane) displays the anatomic variations of ostiomeatal unit, that have been reported to predispose sinusitis. They are nasal septal deviation, pneumatization and paradoxical curvature of the middle turbinate, pneumatization of unciform process, Haller's cells, prominent agger nasi cell and ethmoid bulla. The endoscopic endonasal surgery landmarks, the individual morphologic variations, the topographic relations to the orbit and to the brain are also well shown by CT.

Ethmoid Bone↗

PubMed1998

[Evaluation of the cystic duct and cysticohepatic junction with MR cholangiography: comparison of various techniques and clinical evaluation with respiratory-triggered three-dimensional multislab technique].

The purpose of this study was to evaluate depiction of the cystic duct and cysticohepatic junction by MR cholangiography (MRC). In 10 volunteers, MR cholangiograms were obtained by breath-hold two-dimensional (2D), respiratory-triggered 2D, respiratory-triggered three-dimensional (3D) single slab, and 3D multislab techniques. The images then were compared qualitatively. MRC using the respiratory-triggered 3D multislab techniques was evaluated as better than the other techniques, and was performed in 35 patients. Depiction of the anatomy of the cystic duct and cysticohepatic junction were evaluated. In 8 of 35 patients, MRC images were compared with those obtained by endoscopic retrograde cholangiography (ERC). The cystic duct and cysticohepatic junction were visualized adequately in 93% of volunteers and patients by the respiratory-triggered 3D multislab technique. Anatomic variations in the cystic duct and cysticohepatic junction were evaluated. The frequency of anatomic variations was the same as previously reported. The anatomic evaluations obtained by MRC were correlated closely with those obtained by ERC in 8 patients. In conclusion, MRC with the respiratory-triggered 3D multislab techniques is useful in evaluation of the cystic duct and cysticohepatic junction.

Adult↗

PubMed2003

[Hepatic artery system variations correlated to split-liver surgery: anatomic study in cadavers].

BACKGROUND: The liver donor shortage and the higher demand on liver transplantation led to advanced liver surgery techniques in order to better utilization of the cadaveric liver donors. That is why the split-liver technique had been applicated in liver transplantation where the liver after been divided into two lobes would be implanted in two recipients. AIMS: This paper has the goal of study both the extra-hepatic arterial distribuition and anatomie of the liver with application on the split-liver transplantation separating the liver in right and left hepatic lobe. PATIENTS AND METHODS: The authors studied 60 livers from fresh cadaver looking at hepatic artery and its main anatomic variations correlating with split-liver surgery. The liver was split into two portions, right and left lobe. RESULTS: The total liver weight was 1536 +/- 361,8 g, right hepatic lobe 890,3 +/- 230,9 g and left hepatic lobe 649,3 +/- 172,6 g. Common hepatic trunk was found in one (1,6%) case and came from superior mesenteric artery and in another one (1,6%), both left hepatic artery and left gastric artery came from the abdominal aorta. The right hepatic artery raised from celiac trunk in 44 (73,3%) cases, and in 15 (25%) from superior mesenteric artery it was acessory in 11 (18,3%) cases and dominant in 4 (6,6%). The left hepatic artery was acessory of left gastric artery in 2 (3,3%) cases. Hepatic artery trifurcation was found in 9 (15%) cases out of this 6 (10%) to segment IV, 2 (3,3%) to segment III and 1 (1,6%) to segment II. Also we found 2 (3,3%) medium hepatic artery to segment IV. CONCLUSION: Hepatic artery variations allowed liver section into right and left hepatic lobe.

Cadaver↗

PubMed1997

Unusual bifurcation-level variation of the left common carotid artery: anatomic presentation of a surgical case.

We report an anatomical variation of the left common carotid artery in a 65 year old patient with larynx carcinoma, that was detected during a radical neck dissection. The bifurcation of the artery was at the level of sixth cervical vertebra that is significantly lower than the commonly accepted normal level. To the best of our knowledge, there is no other report of a similar variation in the medical literature.

Aged↗

PubMed1996

The variations of Sylvian veins and cisterns in anterior circulation aneurysms. An operative study.

The anatomical variations of Sylvian vein and cistern were investigated during the pterional approach in 230 patients with 276 aneurysms of anterior circulation arteries, that were operated on at the Neurosurgical Department of Atatürk University Medical School. Erzurum, Türkiye. All patients underwent radical surgery for aneurysm by the right or left pterional approach. The findings were recorded during surgical intervention and observed through the slides and videotapes of the operations. In our study, we surgically classified the variations of the Sylvian vein, according to its branching and draining patterns. Type I: The fronto-orbital (frontosylvian), fronto-parietal (parietosylvian) and anterior temporal (temporosylvian) veins drain into one sylvian vein. Type II: Two superficial Sylvian veins with separated basal vein draining into the sphenoparietal and Rosenthal's basal vein. Type III: Two superficial Sylvian veins draining into the sphenoparietal and the superior petrosal veins. Type IV: Hypoplastic superficial Sylvian vein and the deep one. Four types of Sylvian vein variations were defined as follows. The Type I was seen in 45% (n = 103), the Type II was found in 29% (n = 67), Type III was recorded in 15% (n = 34) and Type IV, or hypoplastic and deep form was discovered in 11% (n = 26) of patients. The course of the Sylvian vein was on the temporal side (Temporal Coursing) in 70 percent of the cases (n = 160), on the frontal side (Frontal Coursing) in 19% of the patients (n = 45) and in 8 percent of the cases (n = 18) in the deep localization (Deep Coursing). Only 3 percent of the cases (n = 7) showed a mixed course. The variations of the Sylvian cisterns were classified into three types, according to the relationships between the lateral fronto-orbital gyrus and the superior temporal gyrus. In Sylvian Type, the frontal and temporal lobes are loosely (Sylvian Type A, Large) or tightly (Sylvian Type B, Close and Narrow) approximated on the surface thereby covering the area of the Sylvian cistern. In frontal type, the proximal, part of the lateral fronto-orbital gyrus herniated into the temporal lobe. In temporal type, the proximal part of the superior temporal gyrus hemiated into the lateral fronto-orbital gyrus. The variations of the Sylvian cisterns in 230 patients were as follows: in 31% (n = 71) Sylvian Type A, in 21% (n = 48) Sylvian Type B, in 34% (n = 78) Frontal Type, and in 14% (n = 33) Temporal Type. We concluded that venous perfusion disorder of the brain is the most important factor during the pterional approach. Careful intraoperative assessment and protection of the Sylvian vein, which is a surgical pitfall, is an indispensable part of the operation. The recognition of the anatomical variations of the Sylvian vein and cistern, and the detailed knowledge of the microvascular relationships at that level will allow the neurosurgeon to construct a better and safter microdissection plan, to save time and can prevent postoperative neurological deficits.

Adolescent↗

PubMed1998

Morphometry of paranasal sinus anatomy in chronic rhinosinusitis: a pilot study.

OBJECTIVES: To test the null hypothesis that there is no relationship between anatomical variations around the ostiomeatal complex and a predisposition to chronic rhinosinusitis and to define such variations with increased precision. DESIGN: Case-control study of anatomical variations in diseased and normal sinuses. Eight homologous landmarks defining the ostiomeatal complex were located on coronal computed tomographic scans, and their x and y coordinates were digitized using image analysis. SUBJECTS: Ten patients with unilateral sinus disease and 10 subjects without sinus disease (scanned for facial pain) who were selected retrospectively by case-note analysis. RESULTS: Logistic regression showed that the only significant spatial change predictive of a person with rhinosinusitis was the vertical position of the middle turbinate (P=.04), although this was not confirmed by Wilcoxon testing (P>.10). When examined by sinus, however, the horizontal position of the uncinate process was more laterally placed in persons with rhinosinusitis (P=.01), confirmed on Wilcoxon testing (P=.04), but there was no significant difference when compared with sinuses in persons without rhinosinusitis. CONCLUSIONS: Our findings suggest that there are no anatomical differences within the ostiomeatal complex between patients with and without rhinosinusitis. Patients with rhinosinusitis, however, are more likely to develop it in the side with a more laterally positioned uncinate process. Further studies, with more patients and more advanced techniques, including thin-plate spline analysis, are indicated.

Case-Control Studies↗

PubMed1997

Variations of the flexor digitorum superficialis tendon of the little finger.

Seventy cadaveric hands were dissected to study variations of the flexor digitorum superficialis tendon (FDS) to the little finger. Anatomical variations were present in 13% of hands and 10% of the hands showed an anatomical variation that would preclude independent FDS function in the little finger. The distance of the decussation from the metacarpophalangeal joint was measured. A ratio of this distance to proximal phalangeal length was calculated. The ratio indicated that decussation position was independent of phalangeal size.

Cadaver↗

PubMed2006

Circle of Willis variation in a complex stroke presentation: a case report.

BACKGROUND: The impact of circle of Willis anatomical variation upon the presentation of stroke is probably underrecognized. CASE PRESENTATION: A 63-year-old right-handed woman developed a left hemiparesis and right leg weakness sequentially following a road traffic accident (RTA). Despite initial concern about the possibility of cervical spinal cord injury, the final diagnosis was bilateral artery-to-artery embolic cerebral infarction with dominant right internal carotid artery. CONCLUSION: The case illustrates the complex presentation of stroke as a pseudo-cervical cord lesion and the impact of circle of Willis anatomical variation upon the expression of large vessel cerebrovascular disease.

Accidents, Traffic↗

PubMed2006

Right ovarian vein drainage variant: is there a relationship with pelvic varices?

OBJECTIVE: To correlate right ovarian vein (ROV) variations that drain into the right renal vein (RRV) with the presence of pelvic varices. MATERIALS AND METHODS: Routine abdominal multidetector-row computed tomography scans of 324 women were analyzed for the presence and type of ROV variations in this retrospective study. The subjects were divided into 2 groups: those with ROV variations and those without such variations. The diameters of the subjects' ROV, left ovarian vein (LOV), and parauterine veins were measured. Pelvic varices and the presence and degree of ovarian vein reflux were noted and compared between the 2 groups. The chi2-test and the Pearson correlation test were used for statistical analysis. RESULTS: Thirty-two (9.9%) of 324 women studied exhibited ROV variant that drained into the right renal vein, and the remaining subjects (90.1%) exhibited a normal pattern of ROV drainage that flowed directly into the inferior vena cava. Pelvic varices were identified in 59 (18%) of the subjects. Reflux was not observed in any patient without pelvic varices. Fifty-seven of 59 women exhibited ovarian vein reflux. In 56 of those 57 individuals, reflux occurred only in the LOV, and in 1 subject, reflux was noted predominantly in the ROV. No significant relationship between the presence of an ROV that drained into the right renal vein and pelvic varices was noted. CONCLUSION: Although right-sided pelvic varices associated with right ovarian vein drainage variations are rare, anatomic variations of the right ovarian vein are not. This study did not find an association between the presence of right ovarian vein and pelvic varices.

Adult↗

PubMed1998

[Ostium of maxillary sinus in endoscopic sinus surgery].

OBJECTIVE: To determine the clinical significance and operative method of maxillary sinus ostium in the treatment of chronic sinusitis and nasal polyps. METHODS: Fifty-six patients (112 sides) undergone endoscopic sinus surgery were studied. RESULTS: The patency rates of the maxillary ostia in patients with enlarged and unchanged maxillary ostia were 92.9% and 80.4% respectively. Fifty-one patients (64 sides) undergone Caldwell-Luc operations were retrospectively studied. The patency rate of inferior antrostomy was 40.6%. CT scans of the sinuses of 38 cases with unilateral sinisitis or nasal polyps were reviewed. The scaled values of the maxillary hiatus on CT images showed no difference between the normal group and the diseased group. Pneumatization and proliferation of middle turbinate and bent uncinate process were the most common anatomic variation in the diseased group. CONCLUSION: The results suggest that management of anatomic variations surrounding the ostia is very important in the treatment of maxillary ostium.

Adolescent↗

PubMed2006

Common celiaco-mesenterico-phrenic trunk and renal vascular variations.

The knowledge of vascular variations like other anatomical variations, is important during the operative, diagnostic, and endovascular procedures in abdomen. This report describes multiple variations in the upper abdominal vessels as found during the routine dissection in a 60-year-old male cadaver. The variations found were; presence of a celiaco-mesenterico-phrenic trunk, a common inferior phrenic trunk, 2 right renal arteries originating from abdominal aorta, 2 suprarenal arteries originating from the lower right renal artery, 3 right renal veins opening separately into inferior vena cava, and termination of right testicular vein into the lowest vein among the 3 right renal veins. The existence of a celiaco-mesenterico-phrenic trunk has not been reported yet. Although, other variations reported in this case exist as individual variations, a concomitant variation of them has not been reported yet. The knowledge of such variations is quite useful in planning any upper abdominal surgery.

Abnormalities, Multiple↗

PubMed1986

The double puncture: an effective percutaneous technique for removing complex, multiple renal calculi.

Percutaneous nephrostolithotomy, which can require a double puncture, is presently the method of choice in our institution for the removal of renal stones. Patients that underwent this procedure were evaluated to identify the possible reasons for the double puncture. Of 200 patients evaluated, 14 needed a second tract. The three variables that determined whether a second puncture was needed, in order of importance, were number and size of the stones, with second tracts needed in patients with multiple stones and staghorn calculi; anatomical variations of the renal collecting system itself, with bifid systems the most significant anatomic variation; and the dexterity of the radiologist in performing the puncture and the ability of the urologist to extract the stone. Second tracts were needed more frequently in patients who presented with stones in both the lower and middle poles of the collecting systems.

Humans↗

PubMed2003

[Comparison of low dose and standard dose CT in the evaluation of inflammatory diseases of paranasal sinuses].

PURPOSE: The aim of this study was to investigate the diagnostic value of low dose CT (LDCT) by comparing the identification of sinonasal anatomical structures, anatomic variations and detectability of inflammatory changes at low and standard dose CT (SDCT). MATERIALS AND METHODS: A total of 30 patients who were referred to CT scan for the assessment of paranasal sinuses underwent CT examinations at both standard [110 mA, 120 kV, 5 mm collimation (3 mm collimation at the level of the ostiomeatal unit)] and low dose [22 mA, 120 kV, 5 mm collimation (3 mm collimation at the level of the ostiomeatal unit)]. All images were photographed at identical window settings (window width, 4000 HU; window level, 50 HU) on laser film. Ten sinonasal anatomical structures (five on the right and five on the left) and inflammatory mucosal changes were recorded for each patient. The detectability and conspicuity levels were scored for each finding. RESULTS: A total of 297 sinonasal anatomical structures were identified at SDCT, whereas 296 structures were detected at LDCT. Inflammatory mucosal changes and anatomical variations were equally identified at both SDCT and LDCT (p > 0.05). There was no statistically significant difference between SDCT and LDCT in the detection on of anatomical structures, variations and inflammatory changes (p > 0.05). CONCLUSION: The low dose CT protocol used in this study provided images of adequate quality, and proved to be reliable in the evaluation of normal and diseased paranasal sinuses.

Adolescent↗

PubMed2000

Do maxillary sinus retention cysts reflect obstructive sinus phenomena?

OBJECTIVE: To determine the relation of maxillary sinus retention cysts (RCs) to ostiomeatal complex (OMC) obstruction and anatomic variation of the paranasal sinuses. METHODS: The results of 410 computed tomographic scans of the sinuses ordered by otolaryngologists in an academic center during a 1-year period were reviewed. Computed tomographic scans with maxillary sinus RCs were studied to determine cyst characteristics, the Lund score, OMC size and patency, and the presence of anatomic variations. Statistical analysis was conducted to determine the relation of RCs to these factors. RESULTS: The incidence of RCs was 12.4% (51 cases). The mean patient age was 41.3 years, with a female-male ratio of 2.4:1. Nine cases demonstrated bilateral cysts, allowing 42 unilateral cases to be analyzed with the nondiseased side as a control. The mean cyst size was 1.56 cm, and cysts were most commonly located inferiorly (30 [50%]) and were solitary (45 [88%]). The RC side had a higher mean Lund score than the control side (2.62 vs 1.93; P =. 008, Wilcoxon signed rank test). Of the cyst sides, 18 (43%) demonstrated OMC occlusion, vs 15 (36%) for the control side (P =.55, McNemar test). The mean OMC size was smaller for the cyst side vs the control side (0.77 vs 1.35 mm; P =.13). No association was found between RCs and concha bullosa or Haller cells (P =.45 and P =.39, respectively). CONCLUSIONS: Maxillary sinus RCs do not reflect persistent obstructive pathology of the OMC, and are not associated with potentially obstructive anatomic sinus variations. Consideration should be given to not scoring RCs as positive disease during Lund staging.

Adult↗

PubMed2006

Bilateral accessory thoracodorsal artery.

The subscapular artery arises from the third part of the axillary artery and gives off the circumflex scapular and the thoracodorsal arteries. Although anatomical variations of the axillary artery are very common, the existence of a unilateral accessory thoracodorsal artery has been described in the literature only once. There are no reports of bilateral accessory thoracodorsal artery, in the literature. In the present study, a bilateral accessory thoracodorsal artery, originating on either side of the third part of the axillary artery, is described in a 68-year-old female cadaver. All the other branches of the axillary artery had a typical origin, course, distribution and termination. This extremely rare anatomical variation apart from the anatomical importance also has clinical significance for surgeons in this area. Especially, during the dissection or mobilization of the latissimus dorsi that is partly used for coverage problems in many regions of the body and also in dynamic cardiomyoplasty, any iatrogenic injury of this accessory artery may result in ischemia and functional loss of the graft.

Aged↗

PubMed2003

Litigation and the lingual nerve.

PURPOSE: A "malpractice crisis" exists in the United States. Litigation analysis helps to understand the causes and may be useful in prevention of suits. This study reviews litigation regarding the lingual nerve. MATERIALS AND METHODS: Jury verdict reports were obtained from a computerized legal database for the years 1987 through 2000. The study reviews all state and federal civil trials in the United States. Reviews compile information on plaintiffs and defendants, allegations of wrong-doing, reasons for litigation, anatomic sites of injuries, specialties of expert witnesses, verdict results, and awards received. RESULTS: Thirty-three suits from 12 states were obtained. Dentists or oral surgeons were involved in 87%, and otolaryngologists were involved in 13% of suits. Tooth extractions were involved in 79%, and 50% of these resulted in financial awards. Lack of informed consent was alleged in 52% of suits overall and in 46% of tooth extraction suits. Expert witnesses were of the same specialty for both sides in 81%. Inadequate training and selection of the wrong surgical approach were alleged in 18% and 15%, respectively. Anatomic variations were thought to be present in 15%. CONCLUSIONS: Surgeons must be aware of anatomic variations and regions in which injury to the lingual nerve frequently occurs. Written informed consent may help decrease litigation in known risk regions.

Compensation and Redress↗