Direct, Duodenum-Guided Access to the Renal Hilum During Laparoscopic Radical Nephrectomy

AIM: To provide a step-by-step description of the surgical technique that allows for a direct, duodenum-guided access to the renal hilar vessels during laparoscopic radical nephrectomy (LRN). MATERIALS AND METHODS: For a right-sided LRN, a Kocher maneuver exposes the underlying vena cava (VC). The cephalad dissection of its lateral margin leads to the right renal vein (RRV). The right renal artery is identified posteriorly between RRV and VC and clip-secured. The access to the left renal hilum is guided by the identification of the fourth portion of the duodenum and the inferior mesenteric vein. The Treitz ligament is incised. The duodenum is medialized exposing the aortic wall and the left renal vein. The lateral surface of the aorta is carefully dissected till the emergence of the left renal artery. CONCLUSIONS: The described approach, although technically challenging represents a feasible, safe and oncologically valid technique to perform LRN in the hands of an experienced laparoscopist

Direct, Duodenum-Guided Access to the Renal Hilum During Laparoscopic Radical Nephrectomy

AIM: To provide a step-by-step description of the surgical technique that allows for a direct, duodenum-guided access to the renal hilar vessels during laparoscopic radical nephrectomy (LRN). MATERIALS AND METHODS: For a right-sided LRN, a Kocher maneuver exposes the underlying vena cava (VC). The cephalad dissection of its lateral margin leads to the right renal vein (RRV). The right renal artery is identified posteriorly between RRV and VC and clip-secured. The access to the left renal hilum is guided by the identification of the fourth portion of the duodenum and the inferior mesenteric vein. The Treitz ligament is incised. The duodenum is medialized exposing the aortic wall and the left renal vein. The lateral surface of the aorta is carefully dissected till the emergence of the left renal artery. CONCLUSIONS: The described approach, although technically challenging represents a feasible, safe and oncologically valid technique to perform LRN in the hands of an experienced laparoscopist

The specific inherent optical properties of three sub-tropical and tropical water reservoirs in Queensland, Australia

The underwater light climate, which is a major influence on the ecology of aquatic systems, is affected by the absorption and scattering processes that take place within the water column. Knowledge of the Specific Inherent Optical Properties (SIOPs) of water quality parameters and their spatial variation is essential for the modelling of underwater light fields and remote sensing applications. We measured the SIOPs and water quality parameter concentrations of three large inland water impoundments in Queensland, Australia. The measurements ranged from 0.9–42.7 μgl/1 for chlorophyll a concentration, 0.9–170.4 mgl/1 for tripton concentration, 0.36–1.59 m/1 for aCDOM(440) and 0.15–2.5 m for Secchi depth. The SIOP measurements showed that there is sufficient intra-impoundment variation in the specific absorption and specific scattering of phytoplankton and tripton to require a well distributed network of measurement stations to fully characterise the SIOPs of the optical water quality parameters. While significantly different SIOP sets were measured for each of the study sites the measurements were consistent with published values in other inland waters. The multiple measurement stations were allocated into optical domains as a necessary step to parameterise a semi-analytical inversion remote sensing algorithm. This paper also addresses the paucity of published global inland water SIOP sets by contributing Australian SIOP sets to allow international and national comparison

Age and depositional environment of the Draa Sfar massive sulfide deposit, Morocco

The Draa Sfar mineralization consists of two main stratabound orebodies, Sidi M’Barek and Tazacourt, located north and south of the Tensift River (“Oued Tessift”), respectively. Each orebody is comprised by at least two massive sulfide lenses. The hosting rocks are predominantly black shales, although minor rhyolitic rocks are also present in the footwall to the southern orebody. Shales, rhyolitic volcanic rocks, and massive sulfides are all included into the Sarhlef Series, which is recognized as one of the main stratigraphic units of the Moroccan Variscan Meseta. Hydrothermal activity related with an anomalous thermal gradient, together with a high sedimentation rate in a tectonically driven pull-apart marine basin, favored the accumulation of organic-rich mud in the deepest parts of the basin and the sedimentary environment suitable for massive sulfide deposition and preservation. This took place by replacement of the hosting unlithified wet mud below the sediment–water interface. Geochemical data suggest a sedimentary environment characterized by oxic water column and anoxic sediment pile with the redox boundary below the sediment–water interface. The low oxygen availability within the sediment pile inhibited oxidation and pyritization of pyrrhotite. Biostratigraphic analysis, based on the palynological content of the hosting black shales, restricts the age of the sulfides to the Asbian substage (mid-Mississippian). This age is consistent with earlier geochronological constraints