Two-stage approach for surgical treatment of tetralogy of Fallot in underweight children: Clinical and morphological outcomes.

BACKGROUND: Two-stage surgery including right ventricular outflow tract (RVOT) stenting with subsequent total surgical repair (TSG) has been suggested as a promising curative option in infants with tetralogy of Fallot (ToF) having comorbidities such as low body weight. However, data on clinical outcomes of such approach and tissue response to RVOT stenting in underweight infants are scarce. METHODS: We recruited 16 underweight (<3 kg; average weight, 2.2 ± 0.4 and 4.7 ± 0.9 kg at the time of RVOT stenting and TSG, respectively) infants (1-3 months of age, average 28.2 ± 4.3 and 100.2 ± 22.3 days at the time of RVOT stenting and TSG, respectively) with ToF and performed RVOT stenting with the subsequent TSG. Excised stents were embedded into epoxy resin and stained by toluidine blue and basic fuchsin. RESULTS: Fifteen infants had a favorable clinical outcome, probably due to the rapid increase in the body weight, blood oxygen saturation, and left ventricular end-diastolic volume to body surface area ratio indicative of improved pulmonary perfusion. Histological analysis revealed an endothelial cell monolayer at the stent surface with notable neovascularization of stented tissues, which could potentially explain the abovementioned clinical and echocardiography improvements. The only death occurred immediately after RVOT stenting and was caused by a massive subdural hematoma, possibly provoked by grade 2 intraventricular hemorrhage 12 days before the stenting. CONCLUSIONS: We confirm RVOT stenting with the subsequent TSG as a safe and efficient surgical approach for the treatment of underweight children with ToF.

COVID-19 Associated Vasculitis Confirmed by the Tissues RT-PCR: A Case Series Report.

BACKGROUND: Several cases of skin and central nervous system vasculopathy associated with COVID-19 in children have been published, but the information is rather limited. Our study aimed to describe these cases of vasculitis associated with COVID-19 in children. METHODS: In the retrospective-prospective case series study we included information regarding four children with COVID-19-associated vasculitis. In every case, we had a morphological description and the etiology was confirmed via real-time polymerase chain reaction during a tissue biopsy. RESULTS: The most involved systems were skin (4/4), respiratory (3/4), cardiovascular (2/4), nervous (1/4), eye (1/4), kidney (1/4), and inner year (1/4). All patients had increased inflammatory markers and thrombotic parameters (D-dimer). No patient met the criteria for multisystem inflammatory syndrome in children. Two patients met polyarteritis nodosa criteria, one met Henoch-Schonlein purpura criteria, and one met unclassified vasculitis criteria. All patients were treated with systemic glucocorticosteroids (two-pulse therapy). Non-biologic DMARDs were prescribed in all cases; 1/4 patients (25%) was treated with intravenous immunoglobuline, and 3/4 (75%) were treated with biologics (etanercept, tocilizumab, and adalimumab). CONCLUSIONS: Vasculitis associated with COVID-19 could be a life-threatening condition; SARS-CoV-2 might be a new trigger or etiological agent for vasculitis and other immune-mediated diseases. Further research and collection of similar cases are required.

Grinding and polishing instead of sectioning for the tissue samples with a graft: Implications for light and electron microscopy.

A broad use of the graft replacement requires a detailed investigation of the host-graft interaction, including both histological examination and electron microscopy. A high quality sectioning of the host tissue with a graft seems to be complicated; in addition, it is difficult to examine the same tissue area by both of the mentioned microscopy techniques. To solve these problems, we developed a new technique of epoxy resin embedding with the further grinding, polishing, and staining. Graft-containing tissues prepared by grinding and polishing preserved their structure; however, sectioning frequently required the explantation of the graft and led to tissue disintegration. Moreover, stained samples prepared by grinding and polishing may then be assessed by both light microscopy and backscattered scanning electron microscopy. Therefore, grinding and polishing outperform sectioning when applied to the tissues with a graft.