Laparoscopic nephrectomy is cost effective compared with open nephrectomy in a large county hospital.

BACKGROUND AND OBJECTIVES: To evaluate the experience with laparoscopic nephrectomy in a large county hospital and perform a cost comparison between uncomplicated open and laparoscopic nephrectomy. METHODS: Eleven consecutive patients who underwent an uncomplicated laparoscopic nephrectomy in a large county hospital were compared with 8 patients who underwent uncomplicated open nephrectomy during the same period. Patient charts and corresponding billing records were reviewed to determine overall hospitalization cost and individual cost components. RESULTS: No perioperative complications occurred in either the laparoscopic or open group, and no statistically significant differences existed between groups with regard to patient demographics or operative parameters. The overall operating room costs favored the open nephrectomy group by dollars 1070 (P=0.003). However, the overall cost of hospitalization, surgeon professional fees, duration of hospitalization, room and board costs, laboratory, and radiology costs, pharmacy costs, intravenous solution and infusion pump costs all significantly favored the laparoscopic patient group. The mean difference in overall hospital cost between laparoscopic and open nephrectomy was dollars 1211 in favor of laparoscopy (P=0.037). CONCLUSIONS: Our experience with laparoscopic nephrectomy in a large county hospital demonstrates a clear economic advantage in favor of the laparoscopic approach. Given limited funding for public hospitals and a clear patient benefit, laparoscopic nephrectomy should constitute first-line therapy when nephrectomy is indicated.     

Unicompartmental knee arthroplasty: Is robotic technology more accurate than conventional technique?

BackgroundRobotic-assisted unicompartmental knee arthroplasty (UKA) with rigid bone fixation "can significantly improve implant placement and leg alignment. The aim of this cadaveric study was to determine whether the use of robotic systems with dynamic bone tracking would provide more accurate UKA implant positioning compared to the conventional manual technique.MethodsThree-dimensional CT-based preoperative plans were created to determine the desired position and orientation for the tibial and femoral components. For each pair of cadaver knees, UKA was performed using traditional instrumentation on the left side and using a haptic robotic system on the right side. Postoperative CT scans were obtained and 3D-to-3D iterative closest point registration was performed. Implant position and orientation were compared to the preoperative plan.ResultsSurgical RMS errors for femoral component placement were within 1.9 mm and 3.7° in all directions of the planned implant position for the robotic group, while RMS errors for the manual group were within 5.4 mm and 10.2°. Average RMS errors for tibial component placement were within 1.4 mm and 5.0° in all directions for the robotic group; while, for the manual group, RMS errors were within 5.7 mm and 19.2°.ConclusionsUKA was more precise using a semiactive robotic system with dynamic bone tracking technology compared to the manual technique.     

Characterization of the orientation and isometry of Humphrey's ligament

Objectives/purposeThe purpose of this study was to examine the effect of flexion angle on isometry and fiber obliquity of the anterior meniscofemoral ligament (Humphrey's ligament (HL)).MethodsFollowing a medial parapatellar arthrotomy on 7 fresh frozen cadavers, the insertion points of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, and HL were identified. Using a 9 mm circular software tool, virtual fibers were created. Within each virtual graft, a central fiber was calculated and used to generate anisometry profiles for the AL and PM bundles and HL at flexion angles of 0°, 30°, 60°, 90°, and 120°. Previously validated computer navigation software was used to re-create three dimensional bundles to measure fiber obliquity in the sagittal, frontal, and axial planes.ResultsHL length increased with knee flexion from 0 to 120°, and underwent similar length changes as the PCL bundles. In full extension and at 90°, the average length of the PM and AL bundles were not statistically different (p = 0.13 and p = 0.85 respectively). From 0 to 120°, the PM bundle was the most isometric, but the anisometry profile was statistically similar to the AL bundle and HL. In general, HL and the PM bundle had similar graphic trends in terms of fiber obliquity in all planes.ConclusionsUsing computer navigation, we have demonstrated that HL has similar isometry profiles as the PM and AL bundles of the PCL, and “mirrored” the obliquity of the PM bundle in all planes throughout flexion to 120°.     

Superiority of practolol versus propranolol in protection against ventricular fibrillation induced by coronary occlusion

The ability of practolol and propranolol to prevent ventricular fibrillation in experimental anterior myocardial infarction was compared in dogs subjected to ligation of the left anterior descending and first septal coronary arteries. This procedure, which causes ventricular fibrillation in 90 percent of animals within 30 minutes, was performed in control dogs and in dogs pretreated with propranolol (0.5 mg/kg body weight) or with practolol (1.5 to 2.5 mg/kg). These doses produced nearly equivalent shifts in isoproterenol-induced chronotropic dose-response curves, indicating equivalent degrees of beta adrenergic blockade. In 21 dogs with confirmed ligation, cardiogenic shock did not develop. Six of seven control dogs died with ventricular fibrillation. Six of seven dogs pretreated with propranolol also had fibrillation, whereas only one of the seven dogs pretreated with practolol manifested ventricular fibrillation during the 45 minute postligation observation period. Practolol afforded significant protection compared with no treatment or treatment with propranolol (P < 0.05).     

Feasibility of a navigated registration technique in FAI surgery

Introduction  

Arthroscopic femoral osteoplasties might be technically demanding, might cause prolonged operative times and restrict the intraoperative overview. An automated navigated matching process of preoperative CT-data and intraoperative fluoroscopy should allow for noninvasive registration for FAI-surgery.     

Systolic anterior motion begins at low left ventricular outflow tract velocity in obstructive hypertrophic cardiomyopathy

OBJECTIVES: The purpose of this study was to determine whether the dynamic cause for mitral systolic anterior motion (SAM) is a Venturi or a flow drag (pushing) mechanism. BACKGROUND: In obstructive hypertrophic cardiomyopathy (HCM), if SAM were caused by the Venturi mechanism, high flow velocity in the left ventricular outflow tract (LVOT) should be found at the time of SAM onset. However, if the velocity was found to be normal, this would support an alternative mechanism. METHODS: We studied with echocardiography 25 patients with obstructive HCM who had a mean outflow tract gradient of 82 +/- 6 mm Hg. We compared mitral valve M-mode echocardiogram tracings with continuous wave (CW) and pulsed wave (PW) Doppler tracings recorded on the same study. A total of 98 M-mode, 159 CW, and 151 PW Doppler tracings were digitized and analyzed. For each patient we determined the LVOT CW velocity at the time of SAM onset. This was done by first determining the mean time interval from Q-wave to SAM onset from multiple M-mode tracings. Then, CW velocity in the outflow tract was measured at that same time interval following the Qwave. RESULTS: Systolic anterior motion began mean 71 +/- 5 ms after Q-wave onset. Mean CW Doppler velocity in the LVOT at SAM onset was 89 +/- 8 cm/s. In 68% of cases SAM began before onset of CW and PW Doppler LV ejection. CONCLUSIONS: Systolic anterior motion begins at normal LVOT velocity. At SAM onset, though Venturi forces are present in the outflow tract, their magnitude is much smaller than previously assumed; the Venturi mechanism cannot explain SAM. These velocity data, along with shape, orientation and temporal observations in patients, indicate that drag, the pushing force of flow, is the dominant hydrodynamic force that causes SAM.     

Cost comparison for laparoscopic nephrectomy and open nephrectomy: analysis of individual parameters

Objectives. To identify the cost components of laparoscopic nephrectomy (LN) that could be targeted to reduce the cost of the procedure. LN is typically more costly than open nephrectomy (ON) because of longer operative times and the use of disposable equipment.Methods. We compared the overall cost and individual cost centers for uncomplicated LN (n = 11) and ON (n = 8) at a large metropolitan county hospital. A model was created using the DATA program (TreeAge software, version 3.5) to compare the costs of treatment with either ON or LN. We conducted a series of one-way sensitivity analyses to evaluate the effect of varying individual probabilities and costs. Two-way sensitivity analyses were performed to evaluate the costs of ON and LN while varying the hospital length of stay, operative time, and cost of laparoscopic equipment.Results. LN was less costly overall than ON by $1211 (P = 0.037), despite significant differences favoring ON in overall operating room costs and operating room supply costs. The cost superiority of LN was a consequence of statistically significant differences in the cost of hospitalization, including room and board, that favored the laparoscopic group. One-way sensitivity analyses showed that LN was less costly if (a) the operative time of LN was less than 281 minutes; (b) the length of hospitalization after LN was less than 5.8 days; (c) the operating room costs for LN were less than $3439; (d) the laparoscopic equipment costs were less than $2129; (e) the ON time exceeded 78 minutes; (f) the length of hospitalization for ON was more than 3.6 days; or (g) the operating room costs for ON were greater than $1333.Conclusions. The sensitivity analyses enable individual surgeons and institutions to determine the cost impact of ON and LN, given their unique clinical scenarios. At our institution, key cost centers in determining cost effectiveness include length of operating time, hospitalization, and cost of laparoscopic instrumentation for ON and LN. LN is cost effective compared with ON if short operating times and brief length of stays are achieved.