Microcirculatory perfusion disturbances following cardiopulmonary bypass: a systematic review.

BACKGROUND: Microcirculatory perfusion disturbances are associated with increased morbidity and mortality in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Technological advancements made it possible to monitor sublingual microcirculatory perfusion over time. The goal of this review is to provide an overview of the course of alterations in sublingual microcirculatory perfusion following CPB. The secondary goal is to identify which parameter of sublingual microcirculatory perfusion is most profoundly affected by CPB. METHODS: PubMed and Embase databases were systematically searched according to PRISMA guidelines and as registered in PROSPERO. Studies that reported sublingual microcirculatory perfusion measurements before and after onset of CPB in adult patients undergoing cardiac surgery were included. The primary outcome was sublingual microcirculatory perfusion, represented by functional capillary density (FCD), perfused vessel density (PVD), total vessel density (TVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI). RESULTS: The search identified 277 studies, of which 19 fulfilled all eligibility criteria. Initiation of CPB had a profound effect on FCD, PVD, or PPV. Seventeen studies (89%) reported one or more of these parameters, and in 11 of those studies (65%), there was a significant decrease in these parameters during cardiac surgery; the other 6 studies (35%) reported no effect. In 29% of the studies, FCD, PVD, or PPV normalized by the end of cardiac surgery, and in 24% percent of the studies, this effect lasted at least 24 h. There was no clear effect of CPB on TVD and a mixed effect on MFI. CONCLUSION: CPB during cardiac surgery impaired sublingual microcirculatory perfusion as reflected by reduced FCD, PVD, and PPV. Four studies reported this effect at least 24 h after surgery. Further research is warranted to conclude on the duration of CPB-induced microcirculatory perfusion disturbances and the relationship with clinical outcome. TRIAL REGISTRATION: PROSPERO, CRD42019127798.

The Effect of Regional Anaesthesia on Free Flap Survival in Lower Extremity Reconstructions.

Background: The effect of different modalities of anaesthesia in microvascular free flap surgery has been a topic of ongoing debate. Comparative data to study the effect of general anaesthesia and regional anaesthesia in the form of peripheral nerve blocks (PNBs) on lower extremity free flap survival is lacking to date. This study aims to elucidate the effect of regional anaesthesia on flap survival in lower extremity free flap reconstructions. Methods: A retrospective cohort study of all patients who underwent free vascularised flap reconstruction of the lower extremities between 2012 and 2021 at the Amsterdam University Medical Centre (UMC), The Netherlands, and between 2019 and 2021 at the Radboud UMC, Nijmegen, The Netherlands. In this cohort, we analysed partial and total flap failures. Results: In this cohort, 87 patients received a total of 102 microvascular free flap reconstructions of the lower extremity. In 20.5% of these operations, patients received a supplemental PNB. Total flap failure was 23.8% in the regional anaesthesia group compared to 21% in the group with general anaesthesia only (p = 0.779). Operation time was longer for patients with regional anaesthesia (p = 0.057). Length of stay was on average 2 days shorter for patients with supplemental regional anaesthesia (p = 0.716). Discussion: This is the largest cohort comparing flap survival in patients receiving general anaesthesia to general anaesthesia with a PNB in lower extremity reconstructions to date. We cannot attribute a significant beneficial or detrimental effect of regional anaesthesia to flap survival. High failure rates stress the need for future studies. How to cite this article: Koster ITS, den Os MM, Rutten MVH, et al. The Effect of Regional Anaesthesia on Free Flap Survival in Lower Extremity Reconstructions. Strategies Trauma Limb Reconstr 2024;19(1):15-20.

Progression of Hip Dysplasia in Mucopolysaccharidosis Type I Hurler After Successful Hematopoietic Stem Cell Transplantation.

BACKGROUND: Dysostosis multiplex contributes substantially to morbidity in patients with Hurler syndrome (mucopolysaccharidosis type I Hurler phenotype [MPS I-H]), even after successful hematopoietic stem cell transplantation (HSCT). One of the hallmarks of dysostosis multiplex in MPS I-H is hip dysplasia, which often requires surgical intervention. We sought to describe in detail the course of hip dysplasia in this group of patients, as assessed by radiographic analysis, and to identify potential outcome predictors. METHODS: Longitudinal data were obtained from digitally scored pelvic radiographs of patients with MPS I-H using OrthoGon software for parameters including, but not limited to, the acetabular index, migration percentage, Smith ratio, and neck-shaft angle. Scoring was performed independently by two blinded observers. Additional information on genotype, enzyme replacement therapy pre-HSCT, donor chimerism, and enzyme activity post-HSCT were obtained. General trends and potential correlations were calculated with mixed-model statistics. RESULTS: Fifty-two patients (192 radiographs) were included in this analysis. Intraobserver and interobserver variation analysis showed an intraclass correlation coefficient ranging from 0.78 to 1.00. Among the twenty-one patients with follow-up beyond the age of five years, the acetabular index was in the range of severe hip dysplasia in up to 86% of the patients. Severe coxa valga was seen in 91% of the patients. Lateral and superior femoral displacement were highly prevalent, with the migration percentage outside the reference range in up to 96% of the patients. Finally, anterior pelvic tilt increased with age (p = 0.001). No correlations were identified between clinical parameters and radiographic findings. CONCLUSIONS: Our study shows that progressive acetabular dysplasia as well as coxa valga and hip displacement are highly prevalent and progressive over time in patients with MPS I-H, despite successful HSCT. These data may provide essential natural history determinations for the assessment of efficacy of new therapeutic strategies aimed at improving skeletal outcomes in patients with MPS I-H.