Retroperitoneoscopic adrenalectomy - introducing a new surgical technique in South Africa.

BACKGROUND: Posterior retroperitoneoscopic adrenalectomy (PRA) is purported to be superior to the laparoscopic transperitoneal approach (LA) in patients with a select spectrum of benign adrenal pathologies. Advantages attributed to the technique include minimal blood loss, shortened operative times, and decreased postoperative pain, explained anatomically by the direct access to the adrenal gland. Reduced workspace is a limitation. METHODS: A retrospective review of 22 consecutive PRAs performed in a single centre between 1 September 2016 and 30 October 2020 is presented. Two experienced laparoscopic surgeons operated on all patients after acquiring the technique at international centres. Suitable candidates were carefully pre-selected. Non-benign pathology, high vascularity, body mass index (BMI) ≥ 45 kg/m2 and anatomical concerns on prior computed tomography (CT) imaging were exclusion criteria. RESULTS: Twenty-two PRAs were performed for a spectrum of benign adrenal pathologies. Twenty-one surgeries (95%) were completed. A single case of pheochromocytoma required conversion. The procedure was safe, a minor postoperative complication (pneumaturia) occurred in one case, and the mortality rate was 0%. Median operative time (80 minutes) is comparable to other reported series in the literature, with a modest linear descending tendency noted over the study period. Underlying pathology influenced operative times. Pheochromocytomas proved to be most challenging and required careful preoperative evaluation. CONCLUSION: The PRA procedures performed at Tygerberg Academic Hospital were safe and reproducible in a select group of cases with benign adrenal pathology. Endocrine surgeons proficient with laparoscopic techniques should be encouraged to use the PRA approach when encountering adrenal neoplasms that fit the criteria.

Access to chloroquine in patients with rheumatic and musculoskeletal diseases attending rheumatology outpatient clinics during the COVID-19 pandemic.

Herbal medicines made from the bark of the Cinchona tree, and later quinine, have been widely used for centuries to treat medical conditions such as tropical malaria. More recently, chloroquine (CQ) and its synthetic derivatives have been used as antimalarials and to treat systemic lupus erythematosus, rheumatoid arthritis, and in the past 14 months or so, COVID-19 pneumonia. Anecdotal evidence and the erratic covering through social media of its potential efficacy in the treatment of COVID-19 pneumonia have resulted in the widespread off-label use of CQ in South Africa and worldwide. This study aimed to show that access to CQ as a chronic medication for rheumatic and musculoskeletal diseases was limited during the COVID-19 pandemic, and that this resulted in an increased incidence of flares in these patients, affecting their morbidity and potentially leading to mortality.

The determination of the contrast necessary for the detection of small positive or negative contrasting areas in flood field images by employing ROCs.

Flood field images are acquired and inspected visually during weekly quality control procedures for scintillation cameras. Nonuniformities are quantified by parameters such as integral and differential uniformity (IU and DU). This study is a first step toward understanding the relation between the standard quantitative parameters measured in regular quality control procedures and the performance of clinicians in the interpretation of studies conducted with the same scintillation camera. This study quantified the performance of observers to detect nonuniformities in an ideal case. Flood field images (64 x 64) were simulated on a computer. One contrasting area (2 x 2) was superimposed at random positions on each image. Positive and negative contrast values of 10%, 8%, 6%, 4%, 2%, and 0% were employed. The linearly scaled computer images were transferred to film. These films were evaluated by 11 observers to obtain receiver operating characteristic (ROC) curves. The areas (A) below the average ROCs for every contrast value were utilized as an indication of the detectability of the contrasting areas superimposed on the flood images. The results indicate areas with positive contrasts greater than 6% and negative contrasts less than -8% were detected with 95% probability (A greater than or equal to 0.95). These contrasts correspond to optical density differences of greater than 0.051 and less than -0.072, respectively (assuming a gamma, G, or gradient of 2.0 for the x-ray film characteristic curve). The contrast values and optical density differences obtained may serve as guide values, beyond which action must be taken to correct the scintillation camera nonuniformity to ensure optimum imaging. These results can be utilized by other institutions to predict the threshold contrasts of their imaging systems if G can be measured or estimated for the systems.

A new approach to NEMA scintillation camera count rate curve determination.

The method of determining count rate curves suggested by the National Electrical Manufacturers Association (NEMA) is based upon a single reference count rate. Inaccuracies in the reference value are propagated to the rest of the curve values. NEMA also requires the measurement of individual attenuation factors for every absorber. Errors can easily occur during the measurement and during the subsequent calculations which utilize these factors. An alternative approach is suggested: count rate curves are based upon at least five low count rate values and the determination of individual attenuation factors is eliminated. Count rate curves are generated from graphs of the 1n of the observed count rate against the number of equally thick copper absorber plates, by back-extrapolation of a line which is fitted to the linear low count rate data. The method was successfully implemented in practice. Agreement was found between the results of the NEMA method and the alternative method suggested.