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PubMed2005

[Internal carotid artery loop: an uncommon cause of parapharyngeal tumor].

The parapharyngeal space-occupying lessions may develop from any of the structures located inside it. Uncommon although possible ethiologies for them are anatomic variations of the course of the internal carotid artery. These anatomic variants mainly arise from degenerative, mostly age-amplified, causes and lead to elongations, angulations, kinking and tortuosities in the course of the vessel that appear as impressions or protusions of the pharyngeal wall. Utherly unfrecuently lead to loops that may show as large parapharyngeal tumors. This fact should be noticed previously to any invasive procedure to be performed on the patient specially when evidenced in concommitance with an infectious process at the moment of diagnosis. A case of an impressive internal carotid artery loop that conditioned an important parapharyngeal mass in a patient with an associated pharyngeal infection is reported to warn about this rare parapharyngeal space-occupying condition and its potential danger.

Aged↗
PubMed1999

Clinical significance of an extensor tendon anomaly to the little finger--a new finding.

A new anatomical variation of extensor digiti minimi (EDM) was discovered during our anatomical studies. The EDM usually gives one tendon to the little finger to extend the metacarpophalangeal joint (MPJ) independently from the other fingers. The EDM in our cadaver had three tendon slips. It supplied the MPJ of the little finger with two tendon slips. Along with the extensor digitorum communis (EDC), the EDM also had an additional slip to the ring finger MPJ extensor hood apparatus. The little finger also received a separate tendon from EDC.

Finger Injuries↗
PubMed1979

Rhinoplasty record and retrieval system.

The rhinoplastic surgeon must vary technique to fit the anatomic variations of nose and face. Our system to record and correlate preoperative findings with surgical methods could help accomplish this. It includes three forms to record pertinent findings of the history and physical examination, operative findings and techniques, and postoperative evaluations. These forms are numerically coded, and data can be transferred to a punch card system or computer cards for quick and easy retrieval and statistical analysis. The system tries to simplify the many anatomic and surgical variations, yet remain complete. We hope that this system, which has been used in other disciplines, can be applied to rhinoplasty. In this way, more scientific statistical data can be used to support surgical approaches.

Adult↗
PubMed1997

Variations of the middle and inferior right hepatic vein: application in hepatectomy.

We evaluated the anatomic variations of the middle right hepatic vein (MRHV) and inferior right hepatic vein (IRHV) and their clinical application to the possibility of right subtotal hepatectomy. In 400 of normal livers studied with ultrasound, the IRHV was found to drain segment 6 of the liver and flow into the inferior vena cava (IVC) in 72 (18%) cases. In 22 (5.5%) cases, the MRHV was found to drain segment 5 of the liver and flow into the IVC. The size of the IRHV ranged from 0.1 cm to 0.8 cm with an average of 0.46 cm. For the MRHV, the sizes ranged from 0.1 cm to 0.9 cm with an average of 0.34 cm. In 10/79 (12.6%) cases the IRHV and in 4/ 22 (18.1%) cases the MRHV were bigger than the right hepatic vein (RHV). The distance between the RHV and IRHV ranged from 3 cm to 5 cm with an average of 3.7 cm. The distance between the RHV and MRHV ranged from 3 cm to 3.3 cm with an average of 3.1 cm. A hyperechoic edge, similar to that of the portal vein, was observed at the wall of the hypertrophic IRHV and was 0.3 cm or larger in size. Preoperative delineation of this complex venous anatomy is very important. It provides vital information in the preoperative evaluation needed before performing a right subtotal hepatectomy with preservation of segment 6 or segment 5 of the liver, and with RHV resection. Prior to undertaking a right hepatectomy, clamping the hypertrophic MRHV and IRHV electively may minimize intra-operative blood loss and extrahepatic spread of the malignancy.

Adolescent↗
PubMed1996

Variations of the left and middle hepatic veins: application in living related hepatic transplantation.

The anatomic variations of the middle hepatic vein (MHV) and left hepatic vein (LHV) in 200 patients with normal liver function were analyzed using ultrasonography to clarify the feasibility of resecting the left lobe or left lateral segment in living subjects for living related hepatic transplantation (LRHT). The MHV and LHV form a common trunk in 70% of cases but drain independently into the inferior vena cava (IVC) in 30%. In 7% of cases, the left median vein (LMV) drains into the MHV, in 32% of cases the anterior superior segmental vein (ASSV) that drains segment 8 flows into the MHV. The distance between the two confluence points (LHV flows into MHV or IVC and LMV flows into the MHV) ranged from 0.3 cm to 2.5 cm with an average of 0.75 cm. The diameter of the LMV at the point that flows into MHV ranged from 0.3 cm to 0.9 cm. with an average of 0.61 cm. The distance from the IVC to the confluence of the MHV and LHV ranged from 0 cm to 3.5 cm with an average of 1.5 cm in those cases whose MHV and LHV presented as common trunks. Preoperative delineation of this complex venous anatomy is of paramount importance because the hepatic veins have to be transected in the cutting plane of the liver. The location of this plane is determined by the optimal graft volume required, and both the graft and the remnant liver have to retain perfect function. The venous anatomy would change the cutting plane in the living donor and the surgical method of anastomosis for the recipient.

Adult↗
PubMed1994

Heubner's artery variations in anterior communicating artery aneurysms.

This study attempts to analyse the intra-operative anatomical findings of the recurrent artery of Heubner in 48 patients with Anterior Communicating Artery Aneurysm who were operated on at the Neurosurgical Department of Atatürk University Medical School, Erzurum, Türkiye. All patients underwent radical surgery for aneurysm by the right pterional approach. The findings were recorded during surgical intervention and through the dias and videotapes of the operations. The artery of Heubner originated from the junction of the A1 and A2 segments of the anterior cerebral artery (ACA) in 58%, from the A2 segment of ACA in 23%, and from the A1 segment of ACA 4%. It was asymmetrically taking off in 13% and hypoplastic in 2% of the cases. Three types of recurrent artery courses were defined. The type I or the superior course was seen in 71%, the type II or the anterior course was found in 25% and type III or the posterior course was recorded in 4% of patients. We concluded that the recognition of the anatomical variations of the recurrent artery of Heubner and the detailed knowledge of the microvascular relationships of the anterior communicating artery (ACoA) complex, will allow neurosurgeons to construct a better and safer microdissection plan, to save time, and so prevent postoperative neurological deficit.

Adolescent↗
PubMed2006

Extralaryngeal bifurcation of the recurrent laryngeal nerve: a common variation.

Extralaryngeal bifurcation and trifurcation of the recurrent laryngeal nerve (RLN) is not well described in anatomical texts. This significant anatomical variation is important because prevention of vocal cord paralysis requires preservation of all branches of the RLN. The aim of this study was to examine the prevalence of extralaryngeal bifurcation of the RLN seen during thyroid/parathyroid surgeries. All patients undergoing total thyroidectomy, hemithyroidectomy and parathyroidectomy (excluding all minimally invasive procedures) carried out by a single endocrine surgeon from November 2003 to December 2004 were included. Operative data obtained prospectively included the location of the nerve, number of branches and the distance in millimetres from the inferior border of the cricothyroid to the point of bifurcation. A total of 213 (right = 114, left = 99) RLN in 137 patients were studied. Seventy-seven (36%) nerves bifurcated or trifurcated before entry into the larynx. Bifurcations were more common on the right (43%) than on the left (28%) (P = 0.05). Trifurcations were seen in eight nerves, seven on the right and one on the left (P = 0.05). Bilaterally branched RLN were observed in 14 (18%) of 77 patients undergoing a bilateral procedure. One non-RLN was identified on the right. The median distance from the cricothyroid to the point of division was 18 mm on the right and 13 mm on the left. Extralaryngeal division of the RLN is a common anatomical variant occurring more frequently on the right. Unseen branches of the RLN are at risk of injury during surgery. Therefore, great care is required following presumed identification of the RLN to ensure that there are no other unidentified branches.

Adolescent↗
PubMed2000

Surgical anatomy of the bile duct branches of the medial segment (B4) of the liver in relation to hilar carcinoma.

In some patients, hilar bile duct carcinoma can easily spread to the bile duct branches of the caudate lobe (B1) as well as to the bile duct branches of the medial segment (B4), and resection of the inferior portion of the medial segment (S4a) is then required. It is therefore important to understand the detailed anatomy of the B4, its confluence patterns, and its relation to the B1 in order to be able to identify such patients. The confluence pattern of the B4 was studied in 141 specimens (68 adult cadavers and 73 liver casts) and the distance between the left bile duct branches of the caudate lobe (B11) and the B4 was measured in 56 of the 73 casts in which both B11 and B4 were present. Two main gross types of B4 were recognized: type I, in which B4 joined the left hepatic duct (LHD) close to the hilar confluence (35.5%), and type II, in which B4 joined the LHD far from the hilar confluence (54.6%). Analysis of the relationship between B11 and B4 revealed a mean distance between B11 and B4 of 8 mm in type 1, and 17 mm in type II. When the distance is less than 10 mm, B11 and B4 are considered to be located very close to each other, and in such individuals hilar bile duct carcinoma can infiltrate the B4 easily, thereby necessitating the resection of S4a, together with a caudate lobectomy for curative resection. Also, the confluence pattern of the B4 often creates a problem when the LHD is divided and reconstructed during hepatectomy, because of the numerous anatomical variations of the B4 itself. We therefore concluded that a good anatomical knowledge of the B4 and its relation to the B11 is essential in making the decision to perform S4a resection in selected patients with hilar bile duct carcinoma with the aim of curative resection.

Adult↗
PubMed1999

Arterial ring encircling the bile duct with coexisting anomalous liver irrigation.

Analysis of the arterial system of the liver in a 64-year-old male cadaver revealed an anomaly of the branching of the proper hepatic artery. The right branch of the hepatic artery was missing, replaced by two segmental arteries, so that a 'trifurcation' occurred, consisting of two segmental arteries, anterior segmental and posterior segmental, and the left branch of the hepatic artery. These segmental arteries formed an arterial ring around the common hepatic duct, completely encircling it. A single cystic artery unusually originated from the posterior segmental artery. An extremely rare anatomical variation of the dorsal liver segment irrigation proves the fact that anatomical anomalies are usually multiple. The arterial blood supply for the dorsal liver segment is through four separate vessels ('quadruple type'), two originating from the left branch of the hepatic artery and two from the posterior segmental artery. These four arteries presented numerous anastomotic bridges among themselves.

Abnormalities, Multiple↗
PubMed2001

Major variation in carotid bifurcation anatomy: a possible risk factor for plaque development?

BACKGROUND AND PURPOSE: Why is carotid plaque often so strikingly asymmetrical within individuals, and why does the extent of disease vary so considerably between individuals with similar systemic risk factors? Variability of carotid bifurcation anatomy is a possible explanation. Flow models suggest that vessel anatomy, in particular vessel diameter and area ratios, affects plaque formation at arterial bifurcations. However, carotid bifurcation anatomy could only be a major risk factor for plaque formation if it was sufficiently variable. Since very few data exist on the extent of interindividual and intraindividual variability of bifurcation anatomy, we studied 5395 angiograms from the European Carotid Surgery Trial. METHODS: To minimize changes in bifurcation anatomy secondary to atherosclerosis, we excluded vessels with >/=30% stenosis. We measured arterial diameters at disease-free points and calculated the following ratios: internal to common carotid (ICA/CCA), external to common carotid (ECA/CCA), external to internal carotid (ECA/ICA), and outflow/inflow area. For intraindividual asymmetry, we compared the ratios on both sides. RESULTS: Each ratio varied markedly between individuals. The 95% ranges were as follows: ICA/CCA, 0.44 to 0.86; ECA/CCA, 0.34 to 0.80; ECA/ICA, 0.55 to 1.33; and outflow/inflow area, 0.38 to 1.28. The results were very similar in 407 bifurcations with no disease. Among the 755 patients with <30% stenosis bilaterally, side differences of >/=25% were present in 17% (95% CI, 15% to 20%) for the ICA/CCA ratio, 27% (95% CI, 24% to 30%) for the ECA/CCA ratio, 32% (95% CI, 28% to 35%) for the ECA/ICA ratio, and 42% (95% CI, 38% to 45%) for the outflow/inflow area ratio. CONCLUSIONS: We found large interindividual differences in carotid bifurcation anatomy. For example, there was 4-fold variation of the ratio of outflow to inflow area. Intraindividual variation was also considerable. These data highlight the potential importance of anatomic variation as a risk factor for atheroma and provide a firm basis for flow modeling studies.

Carotid Arteries↗
PubMed2003

Stapedectomy and variations of the facial nerve.

The aim of the study was to analyze the incidence of anatomical variations and abnormalities of the facial nerve found during stapedectomy. Specific management in the case of an anomalous course of the facial nerve was also described. A retrospective analysis of clinical records of 316 stapedectomies was carried out in search for facial nerve anomalies. In 25 (7.9%) patients the facial nerve had an abnormal course. Twenty patients exhibited partial and two total overhang of the nerve over the oval window. In two of them the facial nerve was dehiscent in the tympanic segment and in three patients an obliterative type of the disease was also noted. The facial nerve dehiscence without the protrusion was found in two more patients. Another individual demonstrated otosclerotic bone over the facial nerve. In one case a duplicated facial nerve was found. Two branches of the nerve were almost covering the oval window (Fig. 1B). The piston was placed in the footplate between the branches of the duplicated nerve. The patient developed slight facial weakness (grade III in H-B scale) after the surgery. The function of the facial nerve returned to normal within 5 months. Anomalies of the course of the facial nerve can be found in about 8% of stapedectomies and they require specific management. The knowledge of the possible abnormalities and relevant procedures is crucial for safe and successful stapedectomy.

Adolescent↗
PubMed1982

[The surgical consequences of topographical variations of the implantation of the papilla in the duodenum].

The Authors underline the importance of anatomical variations concerning the location of the duodenal papilla. In roughly 75% of cases this structure pierces the duodenal mucosa at D2 and at the level of the lower flexure, in 20% at D3 and in about 6% at D1. Intraoperative cholangiography is most useful to spot the papilla, its position is fundamental from an anatomo-surgical point of view both when this structure is placed at a high level (when performing a gastro-duodenal resection), and when located at D3 level, if sphincterotomy is required. In this latter case the usual incision at 12 hours should be carried out at 9 hours instead in order to avoid surgical damage to the canal of Wirsung running vertically and along the common bile duct.

Ampulla of Vater↗
PubMed2004

A rare anomaly of the extensor digitorum longus.

We encountered the absence of the tendon to the fourth toe of the extensor digitorum longus muscle of the right leg in the body of a 73-year-old Japanese woman during the course of educational dissection at Nagoya City University Medical School. The tendon to the fourth toe of the extensor digitorum longus muscle was solely absent. To our knowledge, this anatomical variation has never been cited in the medical literature. We document the precise gross anatomical findings with some morphometric measurements. Moreover, we discuss the morphology of this anomaly in relation to previously described variations and anomalies of the extensor digitorum longus muscle.

Aged↗
PubMedDate not supplied

Variations of the ophthalmic and middle meningeal arteries: relation to the embryonic stapedial artery.

Recognition of the anatomic variations of the ophthalmic and middle meningeal arteries may be pertinent in tailoring the angiographic study to resolve a given clinical problem. An understanding of these anomalies is based on knowledge of the normal embryology. Unfortunately some early aspects of vascular development remain obscure. Fragmentary observations gleaned from the embryologic literature were correlated with selective and/or subselective angiography performed in 42 patients with such anomalies. This analysis has provided the basis for a tenable scheme for development of the ophthalmic and middle meningeal arteries as they relate to the embryonic stapedial artery. A classification for anomalies of these arteries is proposed based on deviation from this normal embryologic mechanism.

Aorta↗
PubMed1994

Skull-base foramina of the middle cranial fossa: reassessment of normal variation with high-resolution CT.

PURPOSE: To evaluate by means of high-resolution CT the anatomic variations of the middle cranial fossa foramen. METHODS: We examined 123 CT studies of the temporal bone in patients with no evidence of disease that might alter foraminal anatomy. A checklist of known variants and suspected structures was used as each case was systematically examined for the presence or absence of these foramina; variations in size, shape, and location; and relationship of structures to each other. Inclusion criteria were established to eliminate error. RESULTS: The foramen rotundum had a constant appearance. We identified the inferior rotundal canal in 16% of patients and the lateral rotundal canal in 8%. The foramen of Vesalius was present, at least unilaterally, in 80% of our cases. Asymmetry of the foramen of Vesalius did not indicate disease in our patient group. We did not find an inverse relationship between the size of the foramen of Vesalius and that of the ipsilateral foramen ovale. We found variations in the size and shape of the foramen ovale and its confluence with the foramen spinosum (n = 2) and the foramen of Vesalius (n = 8). We did not find an inverse relationship between the size of the foramen ovale and that of the foramen spinosum. The canaliculus innominatus for the lesser superficial petrosal nerve was identified in 16.3% of our patients. Variations of the foramen spinosum that we found include a medial bony defect (26.8%) and absence (3.2%). CONCLUSION: Although it is unlikely that well-formed foramen will be misinterpreted as diseased, it is nonetheless important to recognize foraminal variants and associated neurovascular anatomy.

Adolescent↗
PubMed1997

Mandibular spine: a case report.

This is a brief review of the origin and normal variations of the genial tubercles, and specifically, a mandibular spine as an anatomical variation or abnormality. The case presented is that of abnormal genial tubercles observed during dissection of the floor of the mouth. A review and description on the morphology of the genial tubercles are given.

Aged↗
PubMed2004

Computational anatomy: shape, growth, and atrophy comparison via diffeomorphisms.

Computational anatomy (CA) is the mathematical study of anatomy I in I = I(alpha) o G, an orbit under groups of diffeomorphisms (i.e., smooth invertible mappings) g in G of anatomical exemplars I(alpha) in I. The observable images are the output of medical imaging devices. There are three components that CA examines: (i) constructions of the anatomical submanifolds, (ii) comparison of the anatomical manifolds via estimation of the underlying diffeomorphisms g in G defining the shape or geometry of the anatomical manifolds, and (iii) generation of probability laws of anatomical variation P(.) on the images I for inference and disease testing within anatomical models. This paper reviews recent advances in these three areas applied to shape, growth, and atrophy.

Algorithms↗