Multiple Anatomical Variations Research Articles

Anterior ethmoidal artery at ethmoidal labyrinth: Bibliographical review of anatomical variants and references for endoscopic surgery

IntroductionThe anterior ethmoidal artery (AEA) has a trajectory with multiple anatomical variations. In addition, there are no clear references to locate it, so it is easy to produce an iatrogenic lesion. The goal of this study was to carry out a bibliographical review to analyse variants and endoscopic reference reports in the scientific literature. Material and methodsA review in Medline and Embase data bases was carried out, looking for AEA-related anatomical and radiological studies. After the revision, the principal study results, together with several distances and angles useful for locating the AEA, are presented in this study. ResultsThere were 13 main articles that analysed a total of 1388 AEA. It was absent from 2% to 14%. It was identifiable in computed tomography (CT) between 95% and 100%. It was located between the second and third ethmoidal lamella in 74.2% and at the skull base level in 66.6%. Ethmoidal sinuses pneumatisation was related to AEA location at the skull base. Between 83% and 85.3%, it was found at the suprabullar recess. ConclusionsCT is useful for presurgery planning. AEA are more frequent between the second and third lamella and at skull level. Ethmoidal pneumatisation and Keros grades could be predictive factors for AEA relationship with the skull base level. The AEA, the axilla of the middle turbinate and the superomedial edge of the nose are in a straight line, being a simple and useful reference in endoscopic sinus surgery.

Subarachnoid bleeding into the superior cerebellopontine cistern after radiofrequency trigeminal rhizotomy: case report

Sir, We would like to report an unusual case of a patient suffering from trigeminal neuralgia, who underwent percutaneous radiofrequency trigeminal rhizotomy (RF-TR), and complicated with subarachnoidal bleeding in the superior cerebellopontine cistern. A 68-year-old woman had been suffering from medically intractable trigeminal neuralgia. She had a 6-year history of trigeminal neuralgia at the ophthalmic and maxillary branches of the left trigeminal nerve. Cranial magnetic resonance imaging scans revealed no structural or vascular abnormality. Routine preoperative analyses, including coagulation studies, were normal. The patient underwent RF-TR under intravenously administered sedation and analgesia. The localization was confirmed within the nerve by electrical stimulation at 0.5 V (100 Hz, 0.2 m); and a lesion was made at a temperature of 70°C for 60 s. After the procedure, the patient’s pain resolved completely. However, 12 h after the procedure, sudden onset of severe headache, vomiting and neck stiffness occurred. The initial cranial computed tomography (CT) scan was normal. Lumbar puncture examination revealed bloody cerebrospinal fluid (CSF); the lymphocyte and monocyte proportions were normal. The control cranial CT scan showed subarachnoidal bleeding in the left superior cerebellopontine cistern (Fig. 1). The patient underwent conservative treatment, and neck stiffness and headache improved. She was discharged 7 days after the procedure. Trigeminal RF-TR is an effective and commonly performed procedure for control of medically refractory pain. Surgical procedures, such RF-TR, microvascular decompression, etc, may lead to serious complications. Anesthesia dolorosa, painful dysesthesia, absence of corneal reflex, corneal keratitis, masseter paralysis, septic-aseptic meningitis, cranial nerve palsy (cranial nerves III, IV, VI, VII, and VIII), blindness, carotid puncture, and carotidcavernous fistulae are all potential complications of the RFTR procedure [2]. Thus, all surgeons should be aware of these risks and not consider any of these methods as easy and safe. Meckel’s cave and root entry zone, which are the focus of these intervention methods, are at the same time the areas where multiple anatomic variations and vital structures are located [3]. Meckel’s cave opens through a porus into the cerebellopontine cistern. Meckel’s segment of the trigeminal nerve, which begins at the porus and extends to the trigeminal ganglion, is differentiated from the cavernous segment in the wall of the cavernous sinus. Meckel’s segment is narrower adjacent to the porus and fans out as it approaches the posterior edge of the gasserian ganglion, which is embedded in the dura just anterior to the anterior edge of Meckel’s cave. The superior petrosal sinus extends medially through the upper edge of the porus of Meckel’s cave and above the trigeminal nerve to join the cavernous sinus [1]. Some superior petrosal veins may join the sinus on the medial side of the trigeminal nerve. The SCA A. Savas Department of Neurosurgery, School of Medicine, Ankara University, Ankara, Turkey

Assessment of Mitral Valve Anatomy and Geometry With Multislice Computed Tomography

The purpose of the present study was to assess the anatomy and geometry of the mitral valve by using 64-slice multislice computed tomography (MSCT). Because it yields detailed anatomic information, MSCT may provide more insight into the underlying mechanisms of functional mitral regurgitation (FMR). In 151 patients, including 67 patients with heart failure (HF) and 29 patients with moderate to severe FMR, 64-slice MSCT coronary angiography was performed. The anatomy of the subvalvular apparatus of the mitral valve was assessed; mitral valve geometry, comprising the mitral valve tenting height and leaflet tethering, was evaluated at the anterolateral, central, and posteromedial levels. In the majority of patients, the anatomy of the subvalvular apparatus was highly variable because of multiple anatomic variations in the posterior papillary muscle (PM): the anterior PM had a single insertion, whereas the posterior PM showed multiple heads and insertions (n = 114; 83%). The assessment of mitral valve geometry demonstrated that patients with HF with moderate to severe FMR had significantly increased posterior leaflet angles and mitral valve tenting heights at the central (44.4 degrees +/- 11.9 degrees vs. 37.1 degrees +/- 9.0 degrees, p = 0.008; 6.6 +/- 1.4 mm/m(2) vs. 5.3 +/- 1.3 mm/m(2), p < 0.0001, respectively) and posteromedial levels (35.9 degrees +/- 10.6 degrees vs. 26.8 degrees +/- 10.1 degrees, p = 0.04; 5.4 +/- 1.6 mm/m(2) vs. 4.1 +/- 1.2 mm/m(2), p < 0.0001, respectively), as compared with patients with HF without FMR. In addition, a more outward displacement of the PMs, reflected by a higher mitral valve sphericity index, was observed in patients with HF with FMR (1.4 +/- 0.3 vs. 1.2 +/- 0.3, p = 0.004). Mitral valve tenting height at the central level and mitral valve sphericity index were the strongest determinants of FMR severity. MSCT provides anatomic and geometric information on the mitral valve apparatus. In patients with HF with moderate to severe FMR, a more pronounced tethering of the mitral leaflets at the central and posteromedial levels was demonstrated using MSCT.

Ultrasound‐guided umbilical nerve block in children: a brief description of a new approach

The most popular peripheral nerve blocks used in umbilical hernia repair are rectus sheath block and paraumbilical block. However, multiple anatomic variations have been described and some complications may occur. Ultrasonographic guidance of peripheral nerve blocks has reduced the number of complications and improved the quality of blocks. This case series describes a new ultrasound-guided puncture technique of the 10th intercostal nerve in pediatric umbilical surgery. Ten children (age range: 2-5 years) scheduled for umbilical hernia repair were included. Following the induction of general anesthesia, the ultrasonographic anatomy of the umbilical region was studied with a 10-MHz linear probe. An ultrasound-guided peripheral block of the 10th intercostal nerve in the lateral edge of both rectus abdominis muscles (RMs) was performed (total of 20 punctures). Surgical conditions, intraoperative hemodynamic parameters, and postoperative analgesia by means of the modified CHEOPS scale were evaluated. Umbilical anatomy was clearly identified by ultrasound in all cases. The epigastric vessels were identified--above the umbilicus--within the depth of the muscular mass of the RM. The spread of local anesthetic was ultrasound-controlled in all cases. However, the intercostal nerve could not be visualized. All blocks were effective during the surgery. Postoperative analgesia was only required in two children in the second postoperative hour. There were no complications. Ultrasound guidance enables performance of an effective umbilical block in the lateral edge of RM. Further studies should be carried on to visualize the intercostal nerve and to compare this technique with the classical ones.

Anterior Cervical Approach for Stellate Ganglion and T2 to T3 Sympathetic Blocks: A Novel Technique

Stellate ganglion block is used for the diagnosis and treatment of sympathetically maintained pain syndromes. Multiple anatomic variations and inaccurate sympathetic block may mislead the diagnosis and prevent patients from receiving potentially beneficial interventions. We describe a novel approach to blockade of the sympathetic chain at C7 and at T2 to T3 with a single-needle injection. With the patient in supine position, the uncinate process of C7 is identified fluoroscopically as a target for insertion of a catheter through a Touhy needle. The catheter is directed caudally to the junction of T2 and T3. Contrast injection confirms the spread to the appropriate levels before injection of local anesthetic. This novel approach to blockade of the upper extremity sympathetic innervation may enhance diagnostic accuracy and therapeutic benefit as compared with traditional approaches to the stellate ganglion alone. This approach may be expected to decrease the risk of pneumothorax when compared with the posterior approach to T2 to T3.

Topographical anatomy of the penile arteries.

To determine the relationship of the penile arteries to anatomical landmarks and thus ease their identification, so avoiding injury during surgery. The penile arteries in 12 formalin-preserved adult male cadavers were dissected and the distances measured between the cavernosal arteries and both the endopelvic fascia and distal attachment of the crura to the ischial bones. The distance between the origins of both bulbar and cavernosal arteries, their length and the length of the cavernosal bodies and crural attachments were also measured. Several anatomical variations, e.g. accessory pudendal arteries, multiple cavernosal and bulbar arteries, irrigation of cavernosal bodies by contralateral branches, anastomosis of cavernosal arteries with accessory pudendal branches, dorsal artery or bulbar artery as main branches of accessory pudendal arteries, were observed in 13 of the 24 specimens. The mean distances between the anterior attachment of the crura to the ischial rami and the site on the tunica albuginea where the cavernosal arteries penetrated the cavernosal bodies were 1.26 cm on the right and 0.69 cm on the left. The corresponding measurements between the cavernosal arteries and the endopelvic fascia were 5.68 cm (right) and 4.85 cm (left). The mean extracavernosal lengths of the right and left cavernosal arteries were 2.47 and 2.2 cm, respectively. Multiple anatomical variations of the arterial penile anatomy occur frequently. Surgery at the penile hilum may easily damage the cavernosal arteries, which lie medially to the dorsal nerves and arteries of the penis, have an extracavernosal length of about 2.3 cm and perforate the tunica albuginea about 1 cm distally to the anterior attachment of the crura to the ischial ramus.

Management of the resected root end: a clinical review

Careful management of the resected root end during endodontic surgery is critical to the overall success of the case. After resection, the root structure presents with multiple anatomical variations and considerations at both a macroscopic and microscopic level. These include root outline, canal anatomy, dentinal tubule configuration, presence of a smear layer and root canal filling material. Proper assessment of these variables will dictate the best methods for root-end management, along with the attainment of an anatomically compatible root face for optimal healing of the periradicular tissues.