Single-access transumbilical laparoscopic appendectomy and cholecystectomy using new curved reusable instruments: a pilot feasibility study.

BACKGROUND: The umbilicus can be considered as the embryological opening for single-access laparoscopic procedures. We report on single-access transumbilical laparoscopic appendectomy (SATLA) and cholecystectomy (SATLC), performed using new curved reusable instruments. PATIENTS AND METHODS: A retrospective review of a prospectively maintained database of 30 patients who underwent SATLA and 20 patients who underwent SATLC between May and November 2009 was undertaken. All procedures were performed with an 11-mm nondisposable trocar for the scope, and curved reusable instruments (Karl Storz-Endoskope, Tuttlingen, Germany) placed transumbilically without trocars. Outcome measures were conversion to standard laparoscopy, operative time, scar length, complications, hospital stay, and use of pain medication. RESULTS: All SATLA patients had acute appendicitis, and SATLC patients had symptomatic gallstones (15), chronic cholecystitis (3), and acute cholecystitis (2). No extraumbilical trocars were necessary. Mean total operative times were 57.3 ± 15.9 min (SATLA) and 73.9 ± 20.1 min (SATLC). Mean laparoscopic times were 39 ± 13.1 min (SATLA) and 57.5 ± 18.9 min (SATLC). Mean scar lengths were 14.8 ± 2.2 mm (SATLA) and 15.8 ± 2.3 mm (SATLC). Five SATLA patients and one SATLC patient developed postoperative complications. Mean hospital stay was 2.9 ± 1.3 days for SATLA patients and 1.8 ± 0.8 days for SATLC patients. Pain medication used was minimal. At the minimum follow-up of 3 months no late complications were registered. CONCLUSIONS: SATLA and SATLC can be performed safely using curved reusable instruments, which helps avoid the conflict between the surgeon's hands or between the instruments' tips and allows the surgeon to operate in an ergonomic position. The reusable instruments kept the cost similar to that of classic laparoscopy.

Expression of adenosine A 2A receptors in the rat lumbar spinal cord and implications in the modulation of N-methyl-d-aspartate receptor currents.

BACKGROUND: The presence of A(2A) receptors in the dorsal horn of the spinal cord remains controversial. At this level, activation of N-methyl-d-aspartate (NMDA) receptors induces wind-up, which is clinically expressed as hyperalgesia. Inhibition of NMDA receptor currents after activation of A(2A) receptors has been shown in rat neostriatal neurons. In this study, we sought to establish the presence of adenosine A(2A) receptors in the lamina II of the rat lumbar dorsal horn neurons and investigated whether the activation of A(2A) receptors is able to modulate NMDA receptor currents. METHODS: Experiments were conducted in the rat lumbar spinal cord. The presence of adenosine A(2A) receptor transcripts inside the lumbar spinal cord is assessed with the reverse transcriptase polymerase chain reaction (RT-PCR) technique. Western blot experiments are performed at the same level. The RT-PCR technique is also performed specifically in the lamina II, and the presence of adenosine A(2A) receptor transcripts is assessed in neurons from the lamina II with the single-cell RT-PCR technique. The effect of adenosine A(2A) receptor activation on NMDA receptor currents is studied by the whole-cell configuration of the patch clamp technique. RESULTS: RT-PCR performed on the lumbar spinal cord revealed the presence of adenosine A(2A) receptor transcripts. Western blot experiments revealed the presence of A(2A) receptors in the lumbar spinal cord. RT-PCR performed on the substantia gelatinosa also revealed the presence of adenosine A(2A) receptor transcripts. Finally, single cell RT-PCR revealed the presence of adenosine A(2A) receptor transcripts in a sample of lamina II neurons. Patch clamp recordings showed an inhibition of NMDA currents during the application of a selective A(2A) agonist. CONCLUSIONS: These results demonstrate the presence of A(2A) receptor on neurons from the substantia gelatinosa of the rat lumbar dorsal horn and the inhibition of NMDA-induced currents by the application of a selective A(2A) receptor agonist. Therefore, A(2A) receptor ligands could modulate pain processing at the spinal cord level.