Petar Bosnjakovic

Characteristics of a pMOSFET suitable for use in radiotherapy

The paper describes dose response and signal fading of Al-gate p-channel (metal oxide semiconductor field effect transistors) MOSFETs in the range of gamma radiation doses used in radiation therapy. MOSFETs with thicknesses of the gate oxide layer of 1 μm and 400 nm were used. The response was characterized by the threshold voltage shift and was studied as a function of the absorbed dose and time after irradiation. The dosimeters with the 1-μm-thick oxide layer can be effectively used for measuring doses in the 0.1-5 Gy range. The dosimeters with 400-nm-thick oxide layer are suitable for measuring doses above 5 Gy. Both types of the dosimeters retain dosimetric information for long periods of time.

Multichannel fenestration of the petrous and cavernous segments of the internal carotid artery associated with two small carotid canals.

A fenestration is defined as a division of the arterial lumen into distinctly separate channels, each with its own endothelial and muscularis layers, while the adventitia may be shared. Duplication, by contrast, is defined as two distinct arteries with separate origins and no distal arterial convergence. Fenestrations can range from a small focus of divided tissue to long segment duplications. They are the result of partial failure of fusion of paired primitive embryologic vessels or incomplete obliteration of different anastomosis in a primitive vascular network [1]. Fenestration, or duplication, of the internal carotid artery (ICA) is considered as an extremely rare anatomic variant. The prescens of greater than two channels in a long segment of the ICA has not been previously described. We report a case of multichannel fenestrations of the petrous and cavernous segments of the ICA associated with two small carotid canals. A 58-year-old man with no remarkable medical history was admitted to the Department of Neurology for transient ischemic attack involving the right upper extremity. At admission, his general and neurologic examinations were normal. Brain CT findings were unremarkable expect for narrow right carotid canal (Fig. 1). The inferior part of the carotid canal was divided by a bony septum into two smaller canals. CT angiography revealed hypoplastic cervical segment of the right ICA and multiple vessels in the petrous canal, and parasellar area converging to the intradural paraclinoid segment of the ICA (Fig. 2). Digital subtraction angiography (DSA) was performed. Right carotid angiogram (Fig. 3a, b) demonstrated small caliber of ICA, including the first (cervical) and second (ascending petrous) segment. Distally, four tortuous vessels with a diameter of 1–2 mm were found along the course of the third (horizontal intrapetrous), fourth (ascending intrapetrous and in foramen lacerum) and fifth (horizontal segment of the carotid siphon) segments. These vessels converged to the sixth (clinoid) segment. The seventh (supraclinoid) segment of ICA and medial cerebral artery were normal. There was hypoplasia of the A1 segment of the anterior cerebral artery. Selective right external carotid artery showed no abnormalities. Angiograms of the left carotid and both vertebral arteries were normal. Our case describes developmental abnormalities of the petrous and cavernous portion of the ICA, consisted of four channel fenestrations associated with two small carotid canals. Fenestration or segmental duplication of the petrous and the cavernous segment of the ICA is considered an extremely rare anatomic variant. To the best of our knowledge, this is the first report of long-segment multichannel fenestration involving petrous and cavernous segments of the ICA. There is only one case of multichannel fenestrations of the petrous segment of the ICA reported by Mangla and Teitelbaum [2]. They described the shortsegment division of the petrous segment into four channels on DSA. The fenestration was approximately 1-cm long. Uchino et al. [3] have published the only case of intracavernous fenestration diagnosed by MR angiography and DSA. They described duplicate arterial lumens just proximal to the supraclinoid segment. Fenestrations in the supraclinoid and cervical segments are more common. D. Stojanov P. Bosnjakovic D. Benedeto-Stojanov S. Petrovic Faculty of Medicine, University of Nis, Nis, Serbia

Ultrasound and magnetic resonance imaging in prenatal diagnosis of sacrococcygeal teratoma: Case report

INTRODUCTION Fetal tumors are relatively rare and the early prenatal diagnosis enables the prediction of possible complications and decision for appropriate treatment. This paper deals with the role of ultrasonography and magnetic resonance imaging in the early prenatal diagnosis of sacrococcygeal teratoma. CASE REPORT A 21-year-old primigravida was found to have a large sacrococcygeal tumor measuring 25 x 30mm, presented mainly as a solid mass, when she underwent the initial ultrasound examination on the first day of 19th week of gestation. There were no other associated anomalies. The second ultrasound examination was obtained after 6 days and revealed that the tumor had doubled its size. The prominent enlargement raised suspicion of immature sacrococcygeal teratoma and thus, fetal magnetic resonance imaging was performed in the 20th gestation week. The examination showed a crococcygeal teratoma presented as a large solid mass with small microcystic areas, the largest diameter being 60mm, completely externally positioned with no intra-pelvic extension. Rapid tumor growth posed a threat to the fetal circulation and it was the main reason when opting for the termination of pregnancy at 20 weeks of gestation. Pathohystological examination confirmed the diagnosis of immature sacrococcygeal teratoma. DISCUSSION In the prenatal period the magnetic resonance imaging of a fetal tumor initially diagnosed by ultrasound examination is an additional part of diagnostic procedure, and it is not contraindicated during pregnancy. Magnetic resonance imaging improves the delineation of the tumor. The prompt prenatal diagnosis of sacrococcygeal teratoma, as well as the detection of possible associated anomalies, is important for the pregnancy management, prediction of possible complications and choice of appropriate treatment. CONCLUSION Ultrasonography and magnetic resonance imaging are noninvasive, compatible and complementary diagnostic modalities in evaluation of sacrococcygeal teratoma in prenatal period.

Preoperative angiographic selective methylene blue staining of large bowel angiodysplasia in an elderly patient case report

Dear Editor: Acute massive lower gastrointestinal bleeding is an important problem in routine surgical practice, with yearly incidence of 20–27 events per 100,000 people and 4–10% mortality. The bleeding occurs primarily in elderly patients and can result in severity ranges from mild anal outlet bleeding to life-threatening disorder. Accurate triage is essential to ensure that these patients receive aggressive supportive care and urgent intervention. In case that urgent surgery is necessary, identification of the bleeding site is mandatory. There are numerous diagnostic procedures which could establish the cause and location of hemorrhage with various degrees of accuracy. Selective angiography is one of the most important methods to identify gastrointestinal tract hemorrhage caused by angiodysplasia, gaining popularity as a means to localize the site of colonic bleeding, making segmental colectomy possible while avoiding the risk of rebleeding associated with “blind” hemicolectomy. According to the literature, angiography can detect the bleeding site in over 80% of the cases. Bearing in mind the origin of the blood vessels which supply the hollow abdominal organs, we most commonly investigate the abdominal aorta branches: truncus coeliacus, arteria mesenterica superior and inferior. In order to improve accuracy, it is possible to administer methylene blue through the placed catheter and thus clearly delineate the place of future resection of a bowel segment during the operation. Angiography has been used to identify the sites of intestinal bleeding for more than five decades. Combined selective arteriography and methylene blue approach was described in 1978 for the first time by Fogler and Golembe. An 80-year-old man was urgently admitted to the clinic for general surgery due to massive hematochezias. On admission, his blood pressure was 80/50 mmHg, pulse 120 beats per minute, hematocrit 23% (normal range 36.0–56.0%), hemoglobin 62 g/L (normal range 110–170 g/L), and erythrocyte number 3.2×10/L (normal range 3.80–5.30×10/L). Rehydration and electrolyte correction were performed with three blood units and one unit of fresh plasma. The result was a better general condition, with normalization of the vital parameters. In his disease history, the patient stated that bleeding started 3 years ago with general weakness and fatigue and occasional presence of fresh blood in the stool. He was examined several times in hospital for anemic syndrome. Gastroscopy showed the existence of gastritis atrophica antralis, and colonoscopy did not show any pathological changes except for the traces of fresh blood in the cecum. As a part of diagnostic examination of the anemic syndrome, he underwent bone marrow biopsy: granulocytic cells had regular maturation course, normoblastic cells were irritated, and megakaryocytes were present. Small intestine passage: duodenum and jejunum were regular. Along its whole length, the ileum was slightly dilated, with irregular folds and spasms, slowed passage, and several discrete thorn-shaped ulcers. Heart–lung radiography showed normal G. Z. Stanojević (*) :D. M. Mihailović : B. B. Branković : M. D. Nestorović Clinic for general surgery, Clinical Centre Niš, Bul.Zorana Djindjica 48, 18000 Nis, Serbia e-mail: stgoran@bankerinter.net

Lateral intra-extraspinal cervical schwannomas: Partial versus total resection

The study involved 27 lateral cervical schwannomas surgically treated in the last 40 years utilizing either partial or total resection. The study aims to compare the results of total and partial resection of spinal lateral schwannoma and to assess the values of partial resection of large lateral cervical schwannomas. We performed a retrospective analysis of 27 patients operated for lateral cervical schwannomas in the period 1971–2010, out of which 11 had partial resection. The average follow-up of the patients was 136.4 months, comparing pre- and postoperative clinical picture, time to relapse, dynamics of yearly growth of schwannomas, and the need for re-resection. The average period of preoperative complaint in lateral cervical schwannomas was 19.6 months. Unilateral cervicobrachialgia as a manifestation of radiculopathy was observed in 85% of LCSs, and, was, as a rule the first symptom of the disease. Surgical treatment of 27 patients with LCSs resulted in recovery or improvement of complaints in 80% of cases. The treatment effect did not depend on the degree of resection. Reoperation was done, on average, 16.3 years after partial resection. The residues of lateral cervical schwannomas stopped growing 15 years after partial resection and underwent cystic degeneration. Partial resection of lateral cervical schwannomas is an excellent alternative to total resection, not only for the elderly or in cases of increased surgical risk, but also as a method of choice since it is more readily available to a larger number of surgeons and associated with low percentages of surgically relevant relapses and high percentages of improvement.

Endovascular treatment of hereditary hemorrhagic telangiectases of the tongue.

Hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu disease, is an autosomal dominant disorder involving vascular abnormalities of various organs. Telangiectases are frequently observed, predominantly on the nasal and oral mucosa. We present a case a of 53-year-old man with the tonge hemorrhagic telangiectases and epistaxis. Selective catheterization and embolization of the right lingual artery led to size redution and no bleeding from tongue telangiectases.