Alumina-on-alumina hip implants: A wear study of retrieved components

Alumina-alumina bearings are among the most resistant to wear in total hip replacement. Examination of their surfaces is one way of comparing damage caused by wear of hip joints simulated in vitro to that seen in explanted bearings. The aim of this study was to determine whether second-generation ceramic bearings exhibited a better pattern of wear than those reported in the literature for first-generation bearings. We considered both macro- and microscopic findings. We found that long-term alumina wear in association with a loose acetabular component could be categorised into three groups. Of 20 specimens, four had 'low wear', eight 'crescent wear' and eight 'severe wear', which was characterised by a change in the physical shape of the bearing and a loss of volume. This suggests that the wear in alumina-alumina bearings in association with a loose acetabular component may be variable in pattern, and may explain, in part, why the wear of a ceramic head in vivo may be greater than that seen after in vitro testing.     

Extracorporeal carbon dioxyde removal for additional pulmonary resection after pneumonectomy

Additional pulmonary surgery in a previously pneumonectomized patient requires apnea during surgical manipulation of the surviving lung. We report on a novel approach to manage the intraoperative apnea period, combining apneic oxygenation and minimally invasive, low flow extracorporeal CO2 removal. A 69-year-old man previously submitted to left pneumonectomy was scheduled for wedge resection of a single right upper lobe lesion. During the intraoperative apnea period, oxygenation was maintained through apneic oxygenation with continuous positive airway pressure (CPAP) of 5 cmH2O and inspiratory oxygen fraction (FiO2) of 1 and respiratory acidosis was prevented through extracorporeal CO2 removal, performed with the Decap? system (Hemodec, Salerno, Italy), a veno?venous pump-driven extracorporeal circuit including a neonatal membrane lung. The extracorporeal circuit was connected to the right femoral vein, accessed via a 14 Fr double lumen catheter. The blood flow through the circuit was 350 mL/min and the sweep flow of oxygen through the membrane lung was 8 L/min. The intraoperative apnea period lasted 13 minutes. Our approach allowed maintaining normocapnia (PaCO2 38,5 and 40 mmHg before and at the end of the apnea period, respectively), preserving oxygenation (P/F ratio 378, 191, 198 and 200 after 3, 6, 9 and 12 min of apnea, respectively). Our report suggests that the minimally invasive CO2 removal associated with apneic oxygenation is an useful technique for managing anesthesiological situations requiring moderate apnea periods.     

Studies on the haemostatic system in peripheral arterial disease 2. Variations in factor VIII components (FVIII:C ; FVIIIR:Ag ; FVIII:WF) before and after venous occlusion

Factor VIII coagulant activity (FVIII:C), ristocetin co-factor or Willebrand Factor activity (FVIII:WF) and antigen related to FVIII (FVIIIR:Ag) were measured in a group of patients with peripheral arterial disease (PAD) and in a comparable control group. No differences were recorded between patients and controls both in basal conditions and after a standardized venous occlusion (VO) test. VO induced a significant increase in all the FVIII components, comparable in the two groups, with only minor variations in the ratios between them, due to a relatively greater response of the two activities with regard to the protein (FVIIIR:Ag) concentration. FVIII:C was significantly correlated with FVIIIR:Ag and with FVIII:WF only in controls in basal conditions, while no correlation was found in PAD group, nor after VO in either group.

Patients with atherosclerosis obliterans seem therefore to have normal levels of FVIII components and to mantain a normal capacity of responding to VO stimulation. FVIII coagulant activity can be acquired in local blood, or, in alternative, FVIII complex can be released as a whole from vascular walls following venous stasis.     

Ipsilateral breast tumor reappearance in patients treated with conservative surgery after primary chemotherapy. The role of surgical margins on outcome

BACKGROUND AND OBJECTIVES: To evaluate the ipsilateral breast tumor reappearance (IBTR) rate after breast conservative surgery (BCS) following primary chemotherapy (PC) and to assess whether positive margins affects IBTR rate and overall survival (OS). METHODS: Three hundred nine women candidates for mastectomy received PC before surgery. One hundred ninety-five patients (63.1%) underwent BCS and 114 patients (36.9%) a modified radical mastectomy. RESULTS: After a median follow-up of 41 months (range 7-90), 13 patients of the 195 treated with BCS had an IBTR (6.7%), 6 patients had a regional relapse (3.1%), 28 women had distant metastases (14.4%). Twenty-three patients died of breast cancer (11.8%). Twenty-four patients treated with BCS had positive margins (12.3%). At 3 years, the crude cumulative incidence of local recurrence was 4.7% in women with negative margins, and 13.3% in women with positive margins (P=0.05). Cumulative incidence of distant metastases was similar in patients with positive and negative margins (P=0.16) and there was no significant difference in terms of OS according to the margin status (P=0.577). CONCLUSIONS: BCS after PC has an acceptable rate of IBTR. After a short follow-up, the presence of positive margins does not affect OS.