Yusuf Hadi

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 A 1 and A 2 segments of the anterior cerebral artery (ACA) in 58%, from the A 2 segment of ACA in 23%, and from the A 1 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.

We investigated the feasibility of using several fast-growing tropical or subtropical hardwood species for timber production by measuring key wood qualities in relationship to the high rates of lateral growth. The trees tested were sampled from even-aged plantations of Acacia mangium, A. auriculiformis, hybrid Acacia (A. mangium × A. auriculiformis), Eucalyptus grandis, E. globulus, and Paraserianthes falcataria (Solomon and Java origin) that had already reached commercial harvesting age. The released strain of the surface growth stress (RS), xylem density (XD), microfibril angle (MFA), and fiber length (FL) were measured at the outermost part of the xylem at breast height in each tree. Results were then compared to the lateral growth rate (radius/age) at breast height, which provides a relative indicator of the amount of tree growth per year. Our findings indicated that RS was constant, regardless of lateral growth rate in each species. Similar results were observed for XD, MFA, and FL, with a few exceptions, suggesting that high growth rates do not intrinsically affect the wood properties of fast-growing tropical or subtropical species that have reached harvesting age. However, special attention must be paid to patterns of xylem maturation when developing plantations of such species.

The efficient use of plantation trees as timber is often lim-ited by the development of checks and splits, and deforma-tions during primary processing operations. These defects are usually more frequent in hardwood plantation species with an initially fast growth rate, which are ...