N. O. Ajayi

Multiple Variations of the Branches of the Brachial Plexus with Bilateral Connections between Ulnar and Radial Nerves

Fueron observadas durante una diseccion de rutina de los miembros superiores de un cadaver caucasico masculino, multiples variaciones de los ramos del plexo braquial. En el lado izquierdo, el nervio musculocutaneo estaba ausente y los musculos del compartimento anterior del brazo estaban inervados por el nervio mediano. El nervio mediano se encontraba formado de tres raices dos provenientes del fasciculo lateral y uno del fasciculo medial del plexo braquial. En el lado derecho, en la mitad distal del brazo, el nervio musculocutaneo genero un largo ramo comunicante con el nervio mediano. Ademas, en el brazo, en ambos miembros superiores existian ramos comunicantes entre los nervios ulnar y radial. La coexistencia de estas variaciones aparece ser unica y no ha sido relatada en la literatura consultada. Son discutidas la significancia anatomica y clinica de estas variaciones.

Anatomic study of the morphology of the right and left coronary arteries

Arising from the aorta, the right (RCA) and left (LCA) coronary arteries provide the arterial supply to both the atria and the ventricles of the heart. An extensive literature review revealed that most studies have either evaluated the morphology of the RCA or the LCA independently. This study aimed to document the relationship between the morphology of the RCA and LCA using coronary angiograms. In addition, variations such as split or double RCA and an absent LCA was documented. A review of 500 coronary angiograms was conducted and the RCA and LCA were classified according to their branching patterns and arterial dominance. The most prevalent branching pattern of the LCA was bifurcation [in 65.8% (³²⁹/₅₀₀)], while trifurcation and quadrifurcation occurred in 20.4% (¹⁰²/₅₀₀) and 1.6% (⁸/₅₀₀), respectively. The LCA was absent in 11.8% (⁵⁹/₅₀₀) of cases with the bifurcation and trifurcation of its branches in 10.8% (⁵⁴/₅₀₀) and 1.4% (⁷/₅₀₀), respectively. The splitting of the RCA occurred in 4.2% (²¹/₅₀₀) of the angiograms. A split RCA with concomitant absent LCA was documented in 1.2% (⁶/₅₀₀) of the angiograms. The RCA and LCA were dominant in 77.2% (³⁸⁶/₅₀₀) and 9.8% (⁴⁹/₅₀₀) of cases respectively, whereas co-dominance occurred in 13% (⁶⁵/₅₀₀) of the sample examined. In most cases where a split RCA was present, the RCA was found to be non-dominant. With the advent of coronary arteriography, a comprehensive understanding of coronary arterial anatomy and their anomalies has become essential.

Arterial Supply to the Rotator Cuff Muscles

El suministro arterial a los musculos del manguito rotador generalmente es proporcionado por las arterias subescapular, circunfleja escapular, circunfleja humeral posterior y supraescapular. Se realizo la diseccion bilateral de la region escapulo humeral de 31 especimenes cadavericos adultos y 19 fetos. El musculo subescapular estaba irrigado por las arterias subescapular, supraescapular y circunfleja escapular. Por otra parte, la arteria supraescapular irrigaba a los musculos supra e infraespinoso. Observamos que los musculos infraespinoso y redondo menor fueron irrigados por la arteria circunfleja escapular. Ademas de las arterias de origen y sus ramas, observamos que los musculos del manguito rotador son irrigados por la arteria escapular dorsal y las arterias toracica lateral, toracodorsal y circunfleja humeral posterior. Las variaciones en la irrigacion de los musculos del manguito rotador registrados en este estudio son unicos y no existe una descripcion referente a ellos en la literatura revisada. Debido a la mayor frecuencia de los procedimientos quirurgicos en la region escapulohumeral, el conocimiento de las variaciones de la irrigacion de los musculos del manguito rotador puede ser de importancia practica para cirujanos y radiologos.

Anthropometry of the Black Adult Tibia: A South African Study

NAIDOO, N.; LAZARUS, L.; AJAYI, N. O. & SATYAPAL, K. S. Anthropometry of the Black Adult tibia: A South African study. Int.J. Morphol., 33(2):600-606, 2015.SUMMARY: The tibia is the medial long bone of the leg and is characterized by a shaft and two expanded extremities. Despitethe recent advent of tibial bone graft harvesting, the tibia has also been confirmed to be of great forensic significance. As t his appears tobe the only tibial dry bone study done in Southern Africa, this study aimed to investigate morphological and morphometric parametersthat are of clinical and anthropometric importance. Morphological and morphometric examination of 302 adult tibial bone specime ns ofBlack South Africans obtained from the osteological bank of the Discipline of Clinical Anatomy at the University of KwaZulu-Nat al wasperformed. The sample consisted of 168 males and 134 females with an age range of 15 to 87 years old. The number of nutrient fo raminawere: (a) One (male: 98.2%; female: 99.3%); (b) Double (male: 1.8%; female: 0.7%); Relationship of nutrient foramen to the sole al line:(a) infero-medial (male: 0.6%; female: 1.5%); (b) inferior but directly opposite the middle of the bone (male: 8.2%; female: 2.2%); (c)infero-lateral (male: 81.8%; female: 88.9%); (d) infero-lateral, along interrosseous crest (male: 4.1%; female: 3.0%); (e) supe ro-medial(male: 4.7%; female: 3.7%); (f) supero-medial, along interrosseous crest (male: 0.6%; female: 0%); (g) supero-lateral (male: 0% ; female:0.7%). Statistically significant differences were recorded in tibial morphometric parameters between males and females. The rel ationshipbetween the number of nutrient foramina and the soleal line was of statistical significance (p= 0.002). The greater prevalence of a singleforamen observed in this study compared favorably with that reported in previous literature. The recognition of the regional di stributionof the nutrient foramina may prevent injury during tibial bone graft procedures. A thorough understanding of the tibial anatomy may alsoassist with the provision of demographic data required in forensic investigation.KEY WORDS: Tibia; Nutrient Foramen; Soleal Line; Morphometry.

Trigeminal Cave and Ganglion: An Anatomical Review

El cavo trigeminal (CT) de la duramadre es un conducto especial que se extiende desde la fosa craneal posterior a la parte posteromedial de la fosa craneal media en la base del craneo. El CT contiene las raices motoras y sensoriales del nervio trigemino (NT), ganglio trigeminal (GT), asi como la cisterna trigeminal. Este estudio tuvo como objetivo examinar la anatomia del CT y GT y para determinar algunos parametros del CT. El estudio se realizo en dos etapas: A) la diseccion anatomica de 30 cabezas seccionadas sagitalmente y B) la inyeccion para estimar volumen. Fueron encontrados tres capas distintas de duramadre asociadas al CT. El CT se relaciono con la arteria carotida interna, el seno cavernoso, el seno petroso superior, el vertice de la porcion petrosa del hueso temporal y la dura endosteal de la fosa craneal media. El volumen medio del CT fue de 0,14 ml. La longitud media y la amplitud del GT fueron 18,3 mm y 7,9 mm, respectivamente. La media del ancho y alto del poro trigeminal fueron 7,9 mm y 4,1 mm, respectivamente; la longitud media de las ramas terminales del GT al salir del craneo fue variable. El conocimiento preciso de la formacion del CT, GT, NT y sus relaciones es necesario para realizar procedimientos quirurgicos exitosos o el bloqueo nervioso localizado en la region del CT.

The impact of left main coronary artery morphology on the distribution of atherosclerotic lesions in its branches.

BACKGROUND Atherosclerotic occlusion of a coronary vessel is the commonest cause of ischaemic heart disease. The distribution of atherosclerotic lesions is not random,with stenoses preferentially situated at branch ostia, bifurcation points, and the proximal segments of daughter vessels. The aim of this study was to determine the effect of the intrinsic anatomical properties of the left main coronary artery(LMCA) on the distribution of atherosclerotic lesions in its branches. MATERIALS AND METHODS A retrospective review of 170 consecutive coronary angiograms obtained from the cardiac catheterisation laboratories of private hospitals in the eThekwini Municipality area of KwaZulu-Natal, South Africa was performed. The LMCA was absent in 19/170 (11.2%). The remaining angiograms(n = 151) were divided into two groups: normal 63/151 (41.7%) and those with coronary artery disease (CAD) 88/151 (58.3%). The CAD group was sub-divided into proximal 42/88 (47.7%), mixed (proximal and distal) 26/88 (29.6%) and distal20/88 (22.7%) sub-groups based on the location of atherosclerotic lesions in the branches of the LMCA. RESULTS AND CONCLUSIONS The mean length, diameter and angle of division of the LMCA were as follows: Total angiograms: 10.4 mm, 3.8 mm and 86.2o; normal group:10.5 mm, 3.9 mm and 85.7o, CAD group: 10.2 mm, 3.7 mm and 86.3o; proximal sub-group: 10.9 mm, 3.7 mm and 91.6o, mixed sub-group - 9.8 mm, 3.7 mm and 85o and distal sub-group - 9.1 mm, 3.8 mm and 79.4o, respectively. The vessels with proximally located lesions were recorded to have longer lengths and wider angles of division than vessels with distal lesions. Coronary angiographic delineation of the LMCA anatomy may be predictive of a coronary arterial arrangement that may favour the progression of proximally located lesions.

Absent Left Main Coronary Artery with Variation in the Origin of its Branches in a South African Population

Coronary artery anomalies are traditionally classified into anomalies of origin, course and termination. One of the anomalies of origin is absence of the left main coronary artery (LMCA), where the left anterior descending (LAD), the circumflex (Cx) and the ramus medianus (RM) (when present) arteries originate directly from the left aortic sinus. The study aimed to document the prevalence of absent LMCA, discuss its possible embryogenesis and clinical relevance. A review of 407 coronary angiograms performed by cardiologists of three private hospitals in the eThekwini Municipality area of KwaZulu‐Natal, South Africa, was performed. The LMCA was absent in 9.6% (39/407) of the coronary angiograms. The LAD and Cx arteries originated directly from the left aortic sinus with a single ostium in 8.6% (35/407) and separate ostia in 1% (4/407) of the angiograms. In four of the angiograms with absent LMCA, a RM artery was recorded originating directly from the left aortic sinus in addition to the LAD and the Cx arteries. Angiographic detection of the anomalies of the coronary arteries is essential in the determination of the significance of such findings and their management.

The intramyocardial left anterior descending artery : prevalence and surgical considerations in coronary artery bypass grafting : vascular surgery

BACKGROUND Major coronary arteries usually have a subepicardial course and only dip into the myocardium near or at their termination. However, occasionally a segment of the epicardial artery may have an intramural course, and it is often referred to as a myocardial bridge. The left anterior descending (LAD) artery is the most commonly bridged vessel. Its prevalence has been evaluated at both autopsy and angiography. However, in the literature reviewed it is apparent that there are no reports of the prevalence of the intramyocardial LAD (IMLAD) artery in coronary artery bypass graft (CABG) series. OBJECTIVES To document the prevalence of the IMLAD artery in a series of CABGs and to describe the surgical techniques used in these cases. METHODS A retrospective analysis of 1349 surgical reports of consecutive CABGs performed over a period of 23 years was conducted. RESULTS An IMLAD artery was present in 293 patients (21.7%). The prevalence was 20.2% (51/253) in females and 22.1% (242/1096) in males. The IMLAD arteries extended into the interventricular septum in 3.8% (11/293) of the patients. CONCLUSION An intramyocardial course of the LAD artery is relatively common in patients undergoing CABG and poses a challenge in bypass grafting. Techniques are described to address this anatomical variation when it is encountered at surgery.

Arterial Variations of the Subclavian-Axillary Arterial Tree: Its Association with the Supply of the Rotator Cuff Muscles

** * * * SUMMARY: The subclavian-axillary arterial tree is responsible for the arterial supply to the rotator cuff muscles as well as other shoulder muscles. This study comprised the bilateral dissection of the shoulder and upper arm region in thirty-one adult and ni neteen fetal cadaveric specimens. The variable origins and branching patterns of the axillary, subscapular, circumflex scapular, thoracodors al, posterior circumflex humeral and suprascapular arteries identified in this study corroborated the findings of previous studies. In additi on, unique variations that are unreported in the literature were also observed. The precise anatomy of the arterial distribution to the ro tator cuff muscles is important to the surgeon and radiologist. It will aid proper interpretation of radiographic images and avoid injury to this area during surgical procedures.

Determination of the median nerve safe-zone in the carpal tunnel using the distal forearm bony prominences

BACKGROUND The compression of the median nerve (MN) in the carpal tunnel (CT) is one of the most common aetiologies of entrapment neuropathy syndromes in clinical practice. The aim of this study was to investigate the relationship of the palpable bony prominences of the distal forearm (radial styloid process [RSP] and ulnar styloid process [USP]) with MN in the CT, in order to determine a safe-zone of the MN during carpal tunnel procedures. MATERIALS AND METHODS This study involved the bilateral dissection of the CT region of 30 adult cadaveric specimens (n = 60). RESULTS The mean distance between the RSP and USP was 49.34 mm. The mean distance of the MN from the RSP and the USP were 22.44 mm and 26.66 mm, respectively. The mean diameter of the MN within the CT deep to the flexor retinaculum was 5.93 mm. In addition, the MN was located postero-lateral and postero-medial to palmaris longus tendon (PLT) in 78.33% and 21.67% of specimens, respectively. CONCLUSIONS This study found that the MN was located less than 60% of the RSP-USP distance from the RSP. Furthermore, the MN was mostly located postero-lateral to the PLT. Therefore, injection or surgical incision made at/medial to a point 60% of the RSP-USP distance from the RSP will be outside the safe-zone of the MN. The knowledge of this surface anatomical relationship of the MN may be useful during decompression for CT syndrome.