Expansile gas kinetics for pneumatic retinopexy.

PURPOSE: To study the behaviour of expansile intravitreal gases and air used in treating rhegmatogenous retinal detachment. METHODS: A validated mathematical model of gas expansion and absorption in human eyes was used to simulate the effect of varying volumes of pure air, SF6, C2F6 and C3F8 injected into the vitreous cavity. Variation in axial length was accounted for by using three different vitreous cavity volumes to represent hypermetropic, emmetropic and myopic eyes. RESULTS: The time course of varying volumes of pure air and fluorinated gases injected into the vitreous cavity were tabulated, with calculated parameters including volume of gas, percentage gas fills and corresponding retinal contact angles at different time points. CONCLUSION: We produced a comprehensive compilation of expansive gas kinetics aiming to facilitate surgeon selection of the most suitable choice of gas and volume to use, tailored to an individual patient's clinical need.

Proton beam therapy in rectal cancer: A systematic review and meta-analysis.

INTRODUCTION: Locally advanced rectal cancer is often treated with neoadjuvant chemoradiotherapy and surgery. Radiotherapy carries significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) has demonstrated to be effective in other cancers, delivering equivalent dosimetric radiation but with the benefit of improved sparing of OAR. This review compares dosimetric irradiation of OAR and oncological outcomes for PBT versus conventional photon-based radiotherapy in locally advanced rectal cancer. METHODS: An electronic literature search was performed for studies with comparative cohorts receiving proton beam therapy and photon-based radiotherapy for rectal cancer. RESULTS: Eight articles with a total of 127 patients met the inclusion criteria. There was significantly less irradiated small bowel with PBT compared to three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) (MD -17.01, CI [-24.06, -9.96], p < 0.00001 and MD -6.96, CI [-12.99, -0.94], p = 0.02, respectively). Similar dosimetric results were observed for bladder and pelvic bone marrow. Three studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43 %, 68 % and 77.2 %, and one study in primary rectal cancer with 100 % disease free survival. CONCLUSION: PBT treatment plans revealed significantly less irradiation of OAR for rectal cancer compared to conventional photon-based radiotherapy. Trials for recurrent rectal cancer and PBT have shown promising results. There are currently no ongoing clinical trials for primary rectal cancer and PBT. More research is required to validate its potential role in dose escalation, higher complete response rate and organ preservation without increasing toxicity.

The effect of GMFCS level, age, sex, and dystonia on multi-dimensional outcomes after selective dorsal rhizotomy: prospective observational study.

PURPOSE: Investigate the effect of age category (1-9 years vs 10-18 years), sex, Gross Motor Function Classification System (GMFCS) level, and presence of dystonia on changes in eight function test parameters 24 months after selective dorsal rhizotomy (SDR). METHODS: Prospective, single-center study of all children aged 3-18 years with bilateral cerebral palsy with spasticity who underwent SDR at a tertiary pediatric neurosurgery center between 2012 and 2019. A linear mixed effects model was used to assess longitudinal changes. RESULTS: From 2012 to 2019, 42 children had follow-up available at 24 months. Mean GMFM-66 scores increased after SDR (mean difference 5.1 units: 95% CI 3.05-7.13, p < 0.001). Statistically significant improvements were observed in CPQoL, PEDI Self-care and Mobility, 6MWT, Gillette, and MAS scores. There was no significant difference in the improvements seen for age category, sex, GMFCS level, and presence of dystonia for most of the parameters tested (5/8, 6/8, 5/8, and 6/8 respectively). CONCLUSION: SDR may improve gross and fine motor function, mobility and self-care, quality of life, and overall outcome based on extensive scoring parameter testing at 24 months. Atypical patient populations may benefit from SDR if appropriately selected. Multi-center, prospective registries investigating the effect of SDR are required.

Conventional versus miniaturized cardiopulmonary bypass: A systematic review and meta-analysis.

Objective: A meta-analysis of randomized controlled trials was performed to compare the effects of miniaturized extracorporeal circulation (MECC) and conventional extracorporeal circulation (CECC) on morbidity and mortality rates after cardiac surgery. Methods: A comprehensive literature search was conducted using Ovid, PubMed, Medline, EMBASE, and the Cochrane databases. Randomized controlled trials from the year 2000 with n > 40 patients were considered. Key search terms included variations of "mini," "cardiopulmonary," "bypass," "extracorporeal," "perfusion," and "circuit." Studies were assessed for bias using the Cochrane Risk of Bias tool. The primary outcomes were postoperative mortality and stroke. Secondary outcomes included arrhythmia, myocardial infarction, renal failure, blood loss, and a composite outcome comprised of mortality, stroke, myocardial infarction and renal failure. Duration of intensive care unit, and hospital stay was also recorded. Results: The 42 studies eligible for this study included a total of 2154 patients who underwent CECC and 2196 patients who underwent MECC. There were no significant differences in any preoperative or demographic characteristics. Compared with CECC, MECC did not reduce the incidence of mortality, stroke, myocardial infarction, and renal failure but did significantly decrease the composite of these outcomes (odds ratio, 0.64; 95% confidence interval [CI], 0.50-0.81; P = .0002). MECC was also associated with reductions in arrhythmia (odds ratio, 0.67; 95% CI, 0.54-0.83; P = .0003), blood loss (mean difference [MD], -96.37 mL; 95% CI, -152.70 to -40.05 mL; P = .0008), hospital stay (MD, -0.70 days; 95% CI, -1.21 to -0.20 days; P = .006), and intensive care unit stay (MD, -2.27 hours; 95% CI, -3.03 to -1.50 hours; P < .001). Conclusions: MECC demonstrates clinical benefits compared with CECC. Further studies are required to perform a cost-utility analysis and to assess the long-term outcomes of MECC. These should use standardized definitions of endpoints such as mortality and renal failure to reduce inconsistency in outcome reporting.

Outcomes in techniques of valve sparing aortic root replacement: A systematic review and meta-analysis.

OBJECTIVE: To compare clinical outcomes of reimplantation versus remodeling in patients undergoing valve-sparing aortic root replacement (VSRR) surgery. METHOD: Electronic database search at PubMed, Scopus, Embase, Ovid, and Google scholar was performed from inception to January 2020. Primary outcomes were aortic valve (AV) reintervention and postoperative grade of aortic insufficiency (AI) while secondary outcomes were 30-day mortality, reoperation for bleeding, and operative times. RESULTS: A total of 21 articles met the inclusion criteria. A total of 1283 patients had reimplantation while 1150 had remodeling. No difference in preoperative demographics was noted except reimplantation patients were younger (48 ± 16 vs. 56 ± 15 years; p < .00001). The cardiopulmonary bypass and aortic cross-clamp times were shorter in the remodeling cohort (168 ± 38 vs. 150 ± 37 min; p = .0001 and 133 ± 31 vs. 112 ± 30 min; p = .0002, respectively). No difference in concomitant total arch surgery (14% in reimplantation vs. 15% in remodeling; p = .53). Postoperatively, there were similar stroke rates (3% in both cohorts; p = .54), rates of reoperation for bleeding (9% in reimplantation vs. 12% in remodeling; p = .88), and 30-day mortality (3% in reimplantation vs. 4% in remodeling; p = .96). No difference in early AV reintervention (1% in reimplantation vs. 2% in remodeling; p = .07), and late AV reintervention (4% in reimplantation vs. 7% in remodeling; p = .07). The AI of +2 grade was significantly lower in the reimplantation cohort (5% vs. 8%; p = .01). CONCLUSION: Our study shows comparable clinical outcomes between both techniques. The practice of each technique is largely center and surgeon dependent. Larger sample size cohorts with minimal confounding factors are required to confirm the above findings.

Acute type A aortic dissection in-hours versus out-of-hours: A systematic review and meta-analysis.

OBJECTIVE: We sought to compare clinical outcomes in patients with acute type A aortic dissection that undergone surgical repair during in-hours (IH) versus out-of-hours (OOH). METHODS: An electronic literature search was done till March 2020 to include studies with comparative cohorts of IH versus OOH. Primary outcomes were 30-day mortality, stroke, and reoperation for bleeding; secondary outcomes were acute kidney injury, total hospital stay, and intensive care unit stay. RESULTS: Six articles with a total of 3744 patients met the inclusion criteria. Mean age was similar, 60 ± 12 versus 60 ± 13 in IH versus OOH (p = .25). Aortic root and total arch replacement were similar in both cohorts, 22% in IH versus 25% in OOH (risk ratio [RR], 1.10; 95% confidence interval [CI: 0.78, 1.55]; p = .58) and 29% in IH versus 32% in OOH (RR, 0.96; 95% CI [0.89, 1.04], p = .37) respectively. Reoperation for bleeding and stroke rate were similar, with 18% in IH versus 23% in OOH (RR, 0.89; 95% CI [0.73, 1.08]; p = .24), and 12% in IH versus 13% in OOH (RR, 0.83; 95% CI [0.66, 1.03]; p = .09) respectively. Thirty-day mortality was significantly lower in IH (RR, 0.81; 95% CI [0.72, 0.90]; p = .0001). CONCLUSION: There was higher 30-day mortality rate during OOH surgery, yet this difference diminished following sensitivity analysis. There were no significant differences in major postoperative outcomes. Therefore, operating on such cases should be decided on clinical priority without delay.