A new mixed reality tool for training in minimally invasive robotic-assisted surgery.

Robotic-assisted surgery (RAS) is developing an increasing role in surgical practice. Therefore, it is of the utmost importance to introduce this paradigm into surgical training programs. However, the steep learning curve of RAS remains a problem that hinders the development and widespread use of this surgical paradigm. For this reason, it is important to be able to train surgeons in the use of RAS procedures. RAS involves distinctive features that makes its learning different to other minimally invasive surgical procedures. One of these features is that the surgeons operate using a stereoscopic console. Therefore, it is necessary to perform RAS training stereoscopically. This article presents a mixed-reality (MR) tool for the stereoscopic visualization, annotation and collaborative display of RAS surgical procedures. The tool is an MR application because it can display real stereoscopic content and augment it with virtual elements (annotations) properly registered in 3D and tracked over time. This new tool allows the registration of surgical procedures, teachers (experts) and students (trainees), so that the teacher can share a set of videos with their students, annotate them with virtual information and use a shared virtual pointer with the students. The students can visualize the videos within a web environment using their personal mobile phones or a desktop stereo system. The use of the tool has been assessed by a group of 15 surgeons during a robotic-surgery master's course. The results show that surgeons consider that this tool can be very useful in RAS training.

Effects of remote ischemic postconditioning on HIF-1α and other markers in on-pump cardiac surgery.

BACKGROUND: There is a lack of data about the effects of remote ischemic postconditioning (RIPostC) on hypoxia-inducible factor-1α (HIF-1α) plasma levels after on-pump cardiac surgery (OPCS). This study aimed to measure the effects of RIPostC on postoperative HIF-1α plasma levels, cardiac markers and arterial oxygenation in patients undergoing OPCS. METHODS: This single-centre randomized, double blind, controlled trial, enrolled 70 patients (35 control and 35 RIPostC). RIPostC was performed by 3 cycles (5 min of ischemia followed by 5 min of reperfusion) administered in upper arm immediately after the pump period. The primary outcome was to measure HIF-1α plasma levels: before surgery (T0), and 2 h (T1), 8 h (T2), 24 h (T3), 36 h (T4) and 48 h (T5) after RIPostC. As secondary endpoint, Troponin T, CK-MB, CPK plasma levels and PaO2/FiO2 ratio were measured. RESULTS: HIF-1α plasma levels were increased at T1-T3 compared to T0 in both groups (P < 0.001). In the RIPostC group HIF-1α increased compared to the control group: differences between means (95% CI) were 0.034 (0.006-0.06) P = 0.019 at T1; 0.041 (0.013-0.069) P = 0.005 at T2; and 0.021 (0.001-0.042) P = 0.045 at T3. PaO2/FiO2 was higher in the RIPostC group than in the control group: at T3, T4 and T5. Moreover, Troponin T, CK-MB and CPK values decreased in the RIPostC group compared to the control group. CONCLUSIONS: HIF-1α plasma levels increased in control patients during for at least 36 h after OPCS. RIPostC resulted in even higher HIF-1α levels during at least the first 24 h and improved arterial oxygenation and cardiac markers.

Remote Ischemic Preconditioning Decreases Oxidative Lung Damage After Pulmonary Lobectomy: A Single-Center Randomized, Double-Blind, Controlled Trial.

BACKGROUND: During lobectomy in patients with lung cancer, the operated lung is often collapsed and hypoperfused. Ischemia/reperfusion injury may then occur when the lung is re-expanded. We hypothesized that remote ischemic preconditioning (RIPC) would decrease oxidative lung damage and improve gas exchange in the postoperative period. METHODS: We conducted a single-center, randomized, double-blind trial in patients with nonsmall cell lung cancer undergoing elective lung lobectomy. Fifty-three patients were randomized to receive limb RIPC immediately after anesthesia induction (3 cycles: 5 minutes ischemia/5 minutes reperfusion induced by an ischemia cuff applied on the thigh) and/or control therapy without RIPC. Oxidative stress markers were measured in exhaled breath condensate (EBC) and arterial blood immediately after anesthesia induction and before RIPC and surgery (T0, baseline); during operated lung collapse, immediately before resuming two-lung ventilation (TLV) (T1); immediately after resuming TLV (T2); and 120 minutes after resuming TLV (T3). The primary outcome was 8-isoprostane levels in EBC at T1, T2, and T3. Secondary outcomes included the following: NO2+NO3, H2O2 levels, and pH in EBC and in blood (8-isoprostane, NO2+NO3) and pulmonary gas exchange variables (PaO2/FiO2, A-aDO2, a/A ratio, and respiratory index). RESULTS: Patients subjected to RIPC had lower EBC 8-isoprostane levels when compared with controls at T1, T2, and T3 (differences between means and 95% confidence intervals): -15.3 (5.8-24.8), P = .002; -20.0 (5.5-34.5), P = .008; and -10.4 (2.5-18.3), P = .011, respectively. In the RIPC group, EBC NO2+NO3 and H2O2 levels were also lower than in controls at T2 and T1-T3, respectively (all P < .05). Blood levels of 8-isoprostane and NO2+NO3 were lower in the RIPC group at T2 (P < .05). The RIPC group had better PaO2/FiO2 compared with controls at 2 hours, 8 hours, and 24 hours after lobectomy in 95% confidence intervals for differences between means: 78 (10-146), 66 (14-118), and 58 (12-104), respectively. CONCLUSIONS: Limb RIPC decreased EBC 8-isoprostane levels and other oxidative lung injury markers during lung lobectomy. RIPC also improved postoperative gas exchange as measured by PaO2/FiO2 ratio.

Analysis of the prognostic role of an immune checkpoint score in resected non-small cell lung cancer patients.

Tumors develop mechanisms to recruit tolerogenic immune cells and to induce the expression of molecules that act as immune checkpoints. This regulation of the immune microenvironment favors immune tolerance to the neoplastic cells. In this study, we have investigated the prognostic role of immune-checkpoint expression markers in a cohort of resectable non-small cell lung cancer (NSCLC) patients. RNA was isolated from fresh-frozen lung specimens (tumor and normal lung) (n = 178). RTqPCR was performed to analyze the relative expression of 20 immune-related genes that were normalized by the use of endogenous genes selected by GeNorm algorithm. Patients with higher expression levels of IL23A and LGALS2 presented better outcomes. In the clustering expression patterns, we observed that patients with higher expression of immunoregulatory genes had better survival rates. Additionally, these data were used to develop a gene expression score. Since CTLA4 and PD1 were associated with prognosis based on Cox regression analysis (Z-score > 1.5), a multivariate model including these two genes was created. Absolute regression coefficients from this analysis were used in order to calculate the immune-checkpoint score: (PD1×0.116) + (CTLA4×0.059) for each case. Kaplan-Meier survival analysis showed that patients with high immune-checkpoint score have longer overall survival (OS) [NR vs. 40.4 mo, p = 0.008] and longer relapse-free survival (RFS) [82.6 vs. 23 mo, p = 0.009]. Multivariate analysis in the entire cohort indicated that the immune-checkpoint score was an independent biomarker of prognosis for OS [HR: 0.308; 95% CI, 0.156-0.609; p = 0.001] and RFS [HR: 0.527; 95% CI, 0.298-0.933; p = 0.028] in early-stage NSCLC patients. In conclusion, this score provides relevant prognostic information for a better characterization of early stage NSCLS patients with strikingly different outcomes and who may be candidates for immune-based therapies.

Glutathione oxidation correlates with one-lung ventilation time and PO2/FiO2 ratio during pulmonary lobectomy.

OBJECTIVES: During lung lobectomy, the operated lung completely collapses with simultaneous hypoxic pulmonary vasoconstriction, followed by expansion and reperfusion. Here, we investigated glutathione oxidation and lipoperoxidation in patients undergoing lung lobectomy, during one-lung ventilation (OLV) and after resuming two-lung ventilation (TLV), and examined the relationship with OLV duration. METHODS: We performed a single-centre, observational, prospective study in 32 patients undergoing lung lobectomy. Blood samples were collected at five time-points: T0, pre-operatively; T1, during OLV, 5 minutes before resuming TLV; and T2, T3, and T4, respectively, 5, 60, and 180 minutes after resuming TLV. Samples were tested for reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione redox potential, and malondialdehyde (MDA). RESULTS: GSSG and MDA blood levels increased at T1, and increased further at T2. OLV duration directly correlated with marker levels at T1 and T2. Blood levels of GSH and glutathione redox potential decreased at T1-T3. GSSG, oxidized glutathione/total glutathione ratio, and MDA levels were inversely correlated with arterial blood PO2/FiO2 at T1 and T2. DISCUSSION: During lung lobectomy and OLV, glutathione oxidation, and lipoperoxidation marker blood levels increase, with further increases after resuming TLV. Oxidative stress degree was directly correlated with OLV duration, and inversely correlated with arterial blood PO2/FiO2.

Cirugía incompleta del carcinoma adenoide quístico bronquial: una alternativa terapéutica / Incomplete surgery for bronchial cystic adenoid carcinoma: A therapeutic alternative

No disponible

Oxidative lung injury correlates with one-lung ventilation time during pulmonary lobectomy: a study of exhaled breath condensate and blood.

OBJECTIVES: During lung lobectomy, the operated lung is collapsed and hypoperfused; oxygen deprivation is accompanied by reactive hypoxic pulmonary vasoconstriction. After lung lobectomy, ischaemia present in the collapsed state is followed by expansion-reperfusion and lung injury attributed to the production of reactive oxygen species. The primary objective of this study was to investigate the time course of several markers of oxidative stress simultaneously in exhaled breath condensate and blood and to determine the relationship between oxidative stress and one-lung ventilation time in patients undergoing lung lobectomy. METHODS: This single-centre, observational, prospective study included 28 patients with non-small-cell lung cancer who underwent lung lobectomy. We measured the levels of hydrogen peroxide, 8-iso-PGF2α, nitrites plus nitrates and pH in exhaled breath condensate (n = 25). The levels of 8-iso-PGF2α and nitrites plus nitrates were also measured in blood (n = 28). Blood samples and exhaled breath condensate samples were collected from all patients at five time points: preoperatively; during one-lung ventilation, immediately before resuming two-lung ventilation; immediately after resuming two-lung ventilation; 60 min after resuming two-lung ventilation and 180 min after resuming two-lung ventilation. RESULTS: Both exhaled breath condensate and blood exhibited significant and simultaneous increases in oxidative-stress markers immediately before two-lung ventilation was resumed. However, all these values underwent larger increases immediately after resuming two-lung ventilation. In both exhaled breath condensate and blood, marker levels significantly and directly correlated with the duration of one-lung ventilation immediately before resuming two-lung ventilation and immediately after resuming two-lung ventilation. Although pH significantly decreased in exhaled breath condensate immediately after resuming two-lung ventilation, these pH values were inversely correlated with the duration of one-lung ventilation. CONCLUSIONS: During lung lobectomy, the operated lung is collapsed and oxidative injury occurs, with the levels of markers of oxidative stress increasing simultaneously in exhaled breath condensate and blood during one-lung ventilation. These increases were larger after resuming two-lung ventilation. Increases immediately before resuming two-lung ventilation and immediately after resuming two-lung ventilation were directly correlated with the duration of one-lung ventilation.

Oxidative stress injury after on-pump cardiac surgery: effects of aortic cross clamp time and type of surgery.

BACKGROUND: Cardiopulmonary bypass (CPB) in on-pump cardiac surgery can have harmful systemic effects, triggered in part by radical oxygen species (ROS) produced by ischemia-reperfusion in the heart and the lung. We determined the relationship between levels of oxidative stress markers (8-isoprostane and nitrites/nitrates) in plasma with aortic cross clamp duration in patients undergoing cardiac surgery with CPB. METHODS: Thirty patients with CPB were studied: 14 with coronary artery bypass graft surgery and 16 with valve surgery. Plasma levels of 8-isoprostane, and nitrites/nitrates were measured over a 24-hour time course: before (T0) and after CPB: 5 minutes (T1), 1 hour (T2), 12 hours (T3), and 24 hours (T4). RESULTS: Plasma levels of 8-isoprostane and nitrites/nitrates increased early after CPB, with a subsequent and progressive decline. Levels of oxidative stress markers in T1-T2 were positively correlated with the aortic cross clamp duration. Aortic cross clamp duration times greater than 50 minutes were correlated with higher oxidative stress levels. There were no significant differences in the levels of oxidative stress markers between surgery types. CONCLUSION: Cardiac surgery with CPB is associated with an early increase of oxidative stress markers in systemic blood. Aortic cross clamp duration is positively correlated with oxidative stress injury.