Comparative outcomes of lung volume reduction surgery and lung transplantation: a systematic review and meta-analysis.

Background: Lung volume reduction (LVR) and lung transplantation (LTx) have been used in different populations of chronic obstructive pulmonary disease (COPD) patients. To date, comparative study of LVR and LTx has not been performed. We sought to address this gap by pooling the existing evidence in the literature. Methods: An electronic search was performed to identify all prospective studies on LVR and LTx published since 2000. Baseline characteristics, perioperative variables, and clinical outcomes were extracted and pooled for meta-analysis. Results: The analysis included 65 prospective studies comprising 3,671 patients [LTx: 15 studies (n=1,445), LVR: 50 studies (n=2,226)]. Mean age was 60 [95% confidence interval (CI): 58-62] years and comparable between the two groups. Females were 51% (95% CI: 30-71%) in the LTx group vs. 28% (95% CI: 21-36%) in LVR group (P=0.05). Baseline 6-minute walk test (6MWT) and pulmonary function tests were comparable except for the forced expiratory volume in 1 second (FEV1), which was lower in the LTx group [21.8% (95% CI: 16.8-26.7%) vs. 27.3% (95% CI: 25.5-29.2%), P=0.04]. Postoperatively, both groups experienced improved FEV1, however post-LTx FEV1 was significantly higher than post-LVR FEV1 [54.9% (95% CI: 41.4-68.4%) vs. 32.5% (95% CI: 30.1-34.8%), P<0.01]. 6MWT was also improved after both procedures [LTx: 212.9 (95% CI: 119.0-306.9) to 454.4 m (95% CI: 334.7-574.2), P<0.01; LVR: 286 (95% CI: 270.2-301.9) to 409.1 m (95% CI: 392.1-426.0), P<0.01], however, with no significant difference between the groups. Pooled survival over time showed no significant difference between the groups. Conclusions: LTx results in better FEV1 but otherwise has comparable outcomes to LVR.

Infection following CF-LVAD exchange for non-infectious indications: A systematic review and meta-analysis.

INTRODUCTION: Patients on continuous flow left ventricular assist devices (CF-LVADs) often require CF-LVAD exchange. The purpose of this study was to investigate the incidence of infection following CF-LVAD exchange performed for non-infectious indications. METHODS: An electronic literature search was performed to identify all studies of patients undergoing CF-LVAD exchange for pump thrombosis or device malfunction. Of 2,698 articles identified, 6 studies with 81 total patients met the inclusion criteria. Cohort-level data were pooled for meta-analysis. RESULTS: Mean patient age was 60 years (95% CI: 41-78), and 74% were male (95% CI: 61-84). Pump thrombosis was the most common indication for exchange in 70% of patients (95% CI: 47-86). Other indications were driveline fracture and electrical malfunction in 21% (95% CI: 5-56) and 12% (95% CI: 4-33) of patients, respectively. Prior to exchange, 95% of patients were on HeartMate II (HM2) LVADs (95% CI: 86-98) and average duration of support for these patients was 27.1 months (95% CI: 9.3-44.8). The majority were placed on a HM2 following exchange (88% (95% CI: 45-98)) versus HM3 (12% (95% CI: 2-55)). Follow-up was an average of 16.4 months (95% CI: 6.8-26.0). Following exchange, 16 of 81 patients developed infection, with pooled mean incidence of 24% (95% CI: 14-38). 30-day mortality was 14% (95% CI: 7-26). Survival at follow-up was 65% (95% CI: 52-76). CONCLUSIONS: Infection following CF-LVAD exchange can occur at rates higher than those observed with primary implantation; therefore, effective strategies need to implemented early and consistently to help lower infections rates and help improve outcomes following exchange.

Continuous-flow left ventricular assist devices associated survival awaiting heart and heart-kidney transplant.

BACKGROUND: Improvement in continuous-flow left ventricular assist device (CF-LVAD) technology has translated to better outcomes for patients on CF-LVAD support as a bridge-to-transplant. However, data are lacking regarding the subset of CF-LVAD patients with renal failure awaiting simultaneous heart-kidney transplant (HKTx). We sought to better understand the characteristics and outcomes of patients in this group. METHODS: The United Network for Organ Sharing (UNOS) database was used to identify adult patients listed for heart transplant (HTx) or HKTx from January 1, 2009 to March 31, 2017. Patients were followed from time on waitlist to either removal from waitlist or transplantation. Demographic and clinical data for HTx and HKTx patients were assessed. Kaplan-Meier analysis assessed waitlist and post-transplant survival. For waitlisted patients, both death and removal from the waitlist due to deteriorating medical condition were considered events. RESULTS: Overall, 26 638 patients registered for transplant were analyzed. 25 111 (94%) were listed for HTx, and 1527 (6%) for HKTx. 7683 (29%) patients listed for HTx had CF-LVAD support. For those listed for HKTx, 441 (28%) underwent dialysis alone, 256 (17%) had CF-LVAD support alone, and 85 (6%) were treated with both CF-LVAD and dialysis. 15 567 (58%) underwent HTx, and 621 (2%) underwent HKTx. In these groups, post-transplant survival was similar (p = 0.06). Patients listed for HKTx treated with both dialysis and CF-LVAD had significantly worse waitlist survival compared to HKTx recipients (p < 0.001). CONCLUSION: Post-transplant survival is comparable between HTx and HKTx, and early survival is similar between HTx patients and those listed for HTx with CF-LVAD support. However, outcomes on the waitlist for HKTx in CF-LVAD patients on dialysis is significantly worse compared to HKTx recipients. This highlights the need to better account for this patient population when allocating organs.

Bronchial artery revascularization in lung transplantation: a systematic review and meta-analysis.

Background: Bronchial artery revascularization (BAR) during lung transplantation has been hypothesized to improve early tracheal healing and delay the onset of bronchiolitis obliterans syndrome (BOS). We aimed to assess the outcomes of BAR after lung transplantation. Methods: Electronic search in Ovid Medline, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Scopus, and Cochrane Controlled Trials Register (CCTR) databases was performed to identify all relevant studies published about lung transplantation with BAR. Studies discussing lung transplantation utilizing BAR were included while those without outcome data such as BOS and survival were excluded. Cohort-level data were extracted and pooled for analysis. A binary outcome meta-analysis of proportions with logit transformation was conducted. Newcastle-Ottawa scale was used for risk of bias assessment. Results: Seven studies were selected for the analysis comprising 143 patients. Mean patient age was 47 (95% CI: 40-55) years. Sixty-one percent (48-72%) were male. Seventy-three percent (65-79%) of patients underwent double lung transplant while 27% (21-25%) underwent single lung transplant. In patients with postoperative angiography, successful BAR was demonstrated in 93% (82-97%) of all assessed conduits. The 30-day/in-hospital mortality was 6% (3-11%). Seventy-nine percent (63-89%) of patients were free from rejection at three months. Eighty-three percent (29-98%) of patients were free from signs of airway ischemia at three and six months. Pooled survival at one year and five years was 87% (78-92%) and 71% (46-87%), respectively, with a mean follow-up time of 21 (3-38) months. Pooled freedom from bronchiolitis obliterans was 86% (77-91%) at two years. Conclusions: While this systematic review and meta-analysis is limited by the available surgeons, institutions, and papers discussing a highly specialized technique, it does show that BAR is a viable technique to minimize BOS and early anastomotic intervention following lung transplantation.

Assessing donor-recipient size metrics for heart transplant outcomes: UNOS database analysis.

STUDY: There is no widely accepted donor to recipient size-match metric to predict outcomes in cardiac transplant. The predictive ability of size-match metrics has not been studied when recipients are stratified by heart failure etiology. We sought to assess the performance of commonly used size metrics to predict survival after heart transplant, accounting for restrictive versus non-restrictive pathology. METHODS: The UNOS registry was queried from 2000 to 2017 for all primary isolated heart transplants. Donor-recipient ratios were calculated for commonly used size metrics and their association with survival was assessed using continuous, nonlinear analysis. RESULTS: 29 817 patients were identified. Height (P < .001), predicted heart mass (PHM) (P = .003), ideal body weight (IBW) (P < .001) and body mass index (BMI) (P = .003) ratios were significantly associated with survival, while weight and body surface area (BSA) ratios were not. When stratified, only BMI ratio retained significance for both restrictive (P = .051) and non-restrictive (P = .003) subsets. Recipients with restrictive etiology had increased risk of mortality with both a lower and higher BMI ratio. CONCLUSIONS: While many metrics show association with survival in the non-restrictive subset, BMI is the only metric that retains significance in the restrictive subset. Recipients with restrictive and non-restrictive etiologies of heart failure tolerate size mismatch differently.

Extracorporeal life support and cardiopulmonary bypass for central airway surgery: A systematic review.

BACKGROUND: Major airway surgery can pose a complex problem to perioperative central airway management. Adjuncts to advanced ventilation strategies have included cardiopulmonary bypass, veno-arterial, or veno-venous extracorporeal life support. We performed a systematic review to assess the existing evidence utilizing these strategies. METHODS: An electronic search was conducted to identify studies written in English reporting the use of extracorporeal life support (ECLS) during central airway surgery. Thirty-six articles consisting of 78 patients were selected and patient-level data were analyzed. RESULTS: Median patient age was 47 [IQR: 34-53] and 59.0% (46/78) were male. Indications for surgery included central airway or mediastinal cancer in 57.7% (45/78), lesion or injury in 15.4% (12/78), and stenosis in 12.8% (10/78). Support was initiated pre-operatively in 9.9% (7/71) and at the time of induction in 55.3% (42/76). It was most commonly used at the time of tracheal resection/repair [93.2% (68/73)], intubation of the tracheal stump [94.4% (68/72)], and re-anastomosis [94.2% (65/69)]; 13.7% (10/73) patients were supported post-operatively. The most commonly performed surgery was tracheal repair or resection in 70.3% (52/74). Median hospital stay was 12 [8, 25] days and in-hospital mortality was 7.9% (6/76). There was no significant difference in survival between the three groups (p = .54). CONCLUSIONS: Extracorporeal membrane oxygenation offers versatility in timing, surgical approach, and ECLS runtime that makes it a viable addition to the surgical armamentarium for treating complex central airway pathologies.

Outcomes of percutaneous temporary biventricular mechanical support: a systematic review.

Percutaneous biventricular assist devices (BiVAD) are a recently developed treatment option for severe cardiogenic shock. This systematic review sought to identify indications and outcomes of patients placed on percutaneous BiVAD support. An electronic search was performed to identify all appropriate studies utilizing a percutaneous BiVAD configuration. Fifteen studies comprising of 20 patients were identified. Individual patient survival and outcomes data were combined for statistical analysis. All 20 patients were supported with a microaxial LVAD, 12/20 (60%) of those patients were supported with a microaxial (RMA) right ventricular assist device (RVAD), and the remaining 8/20 (40%) patients were supported with a centrifugal extracorporeal RVAD (RCF). All patients presented with cardiogenic shock, and of these, 12/20 (60%) presented with a non-ischemic etiology vs 8/20 (40%) with ischemic disease. For the RMA group, RVAD support was significantly longer [RMA 5 (IQR 4-7) days vs RCF 1 (IQR 1-2) days, p = 0.03]. Intravascular hemolysis post-BiVAD occurred in three patients (27.3%) [RMA 3 (33.3%) vs RCF 0 (0%), p = 0.94]. Five patients received a durable left ventricular assist device, one patient received a total artificial heart, and one patient underwent a heart transplantation. Estimated 30-day mortality was 15.0%, and 78.6% were discharged alive. Both strategies for percutaneous BiVAD support appear to be viable options for severe cardiogenic shock.

Utilization and outcomes of extracorporeal CO2 removal (ECCO2 R): Systematic review and meta-analysis of arterio-venous and veno-venous ECCO2 R approaches.

INTRODUCTION: Extracorporeal carbon dioxide removal (ECCO2 R) provides respiratory support to patients suffering from hypercapnic respiratory failure by utilizing an extracorporeal shunt and gas exchange membrane to remove CO2 from either the venous (VV-ECCO2 R) or arterial (AV-ECCO2 R) system before return into the venous site. AV-ECCO2 R relies on the patient's native cardiac function to generate pressures needed to deliver blood through the extracorporeal circuit. VV-ECCO2 R utilizes a mechanical pump and can be used to treat patients with inadequate native cardiac function. We sought to evaluate the existing evidence comparing the subgroups of patients supported on VV and AV-ECCO2 R devices. METHODS: A literature search was performed to identify all relevant studies published between 2000 and 2019. Demographic information, medical indications, perioperative variables, and clinical outcomes were extracted for systematic review and meta-analysis. RESULTS: Twenty-five studies including 826 patients were reviewed. 60% of patients (497/826) were supported on VV-ECCO2 R. The most frequent indications were acute respiratory distress syndrome (ARDS) [69%, (95%CI: 53%-82%)] and chronic obstructive pulmonary disease (COPD) [49%, (95%CI: 37%-60%)]. ICU length of stay was significantly shorter in patients supported on VV-ECCO2 R compared to AV-ECCO2 R [15 (95%CI: 7-23) vs. 42 (95%CI: 17-67) days, p = 0.05]. In-hospital mortality was not significantly different [27% (95%CI: 18%-38%) vs. 36% (95%CI: 24%-51%), p = 0.26]. CONCLUSION: Both VV and AV-ECCO2 R provided clinically meaningful CO2 removal with comparable mortality.

Complications of Peripheral Cannulation Site in Obese Patients on Adult Extracorporeal Membrane Oxygenation.

Placement of extracorporeal membrane oxygenation (ECMO) in obese patients has been challenging; however, cannulation risk in obese patients has not been clearly investigated. We therefore explored ECMO cannulation complications in this obese population. Data were reviewed from adult ECMO database from 2010 to 2019. Patients were stratified by body mass index (BMI) (normal weight [NW] [BMI 18.5-24.9], overweight [BMI 25-29.9], class I [BMI 30-34.9], class II [BMI 35-39.9], class III [BMI >40]). Patients with central cannulation were excluded from this study. Combined ECMO cannulation complications and survival data were retrospectively analyzed. There were 233 patients, 156 venoarterial (VA) ECMO patients (45 [28%] NW, 51 [33%] overweight, 37 [24%] class I, 12 [8%] class II, and 11 [7.0%] class III) and 77 venovenous (VV) ECMO patients (14 [18%] NW, 13 [17%] overweight, 17 [22%] class I, 11 [14%] class II, and 22 [29%] class III). There were significantly more cannulation site bleeds in VA class III (55%) patients compared with VA NW patients (22%), p = 0.006. There was no significant difference in cannulation site bleeding between BMI groups for VV ECMO. There was no difference in 30 day mortality, ECMO survival for all BMI groups in both VA and VV ECMO. There is significant increased risk of bleeding with peripheral VA cannulation of obese patients with BMI > 35. Cannulating surgeon should be aware of this bleeding risk in morbidly obese patient who undergo VA ECMO.

Development of malignancies and their outcomes in patients supported on continuous-flow left ventricular assist devices-a systematic review.

BACKGROUND: With increased use of continuous-flow left ventricular assist devices (CF-LVAD), development of malignant tumors in this population is not uncommon. We sought to evaluate malignancies in CF-LVAD patients and evaluate the outcomes of treatment strategies. METHODS: Overall, 18 articles consisting of 28 patients were identified who developed malignancies after CF-LVAD placement. Patient-level data were extracted for systematic review. RESULTS: Median patient age was 60 years [59-67] and 85.7% (24/28) were male. CF-LVAD was placed as bridge-to-transplant (BTT) in 60.9% (14/23) of patients. The three most common malignancy types were GI in 35.7% (10/28) of patients, lung in 21.4% (6/28) and skin in 10.7% (3/28). Median time from CF-LVAD implant to malignancy diagnosis was 6.9 [2.5-12.8] months. Metastatic disease occurred in 17.9% (5/28) over a median time of 5.0 [1.0-82.0] months from the diagnosis. Surgical resection of the malignancy was performed in 57.1% (16/28) of patients. Our results showed that while there was a significantly higher probability of survival among patients who underwent surgery versus those who did not, when only stage I and II patients were included in the analysis, this difference was no longer statistically significant. Three patients were relisted for heart transplant after surgical treatment, and two received the transplant. CONCLUSIONS: Surgical management of malignancies in patients on CF-LVADs may improve survival and transplant eligibility status, therefore, a CF-LVAD should not always preclude surgical treatment.

Computational sentiment analysis of an online left ventricular assist device support forum: positivity predominates.

BACKGROUND: The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach. METHODS: Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6). RESULTS: Sixty-six thousand eight hundred and twenty-one unique words were noted, including 4,623 (6.9%) with positive sentiment and 3,248 (4.8%) with negative sentiment. Net sentiment ratio [(number of positive words - number of negative words)/(number of total words)] was 2.1%. Positive sentiment dominated the 20 most commonly used words. Odds ratio of non-neutral words [(number of positive words/number of negative words)] was 1.42, indicating a less obvious disparity in sentiment when expanding analysis beyond the top 20 words. Word cloud analysis of positive and negative sentiments was performed, indicating common use of "infection" (208 mentions) compared to other complications such as "stroke" (29 mentions), "bleeding" (30 mentions), and "thrombosis" or "clot" (32 mentions). CONCLUSIONS: Positive sentiment dominates the most frequently used words, yet this disparity decreases when considering the totality of words. "Infection" is mentioned a disproportionate number of times compared to other LVAD complications. Further research is required to address analysis limitations, including selection bias.

Tricuspid regurgitation associated with implantable electrical device insertion: A systematic review and meta-analysis.

BACKGROUND: Implantable cardioverter defibrillator (ICD) and permanent pacemaker (PPM) lead placement may worsen or result in tricuspid regurgitation (TR). While the association between lead placement and the incidence of TR has been established, current understanding of this problem remains incomplete. This systematic review and meta-analysis sought to pool the existing evidence to better understand the occurrence and severity of TR associated with cardiac implantable electrical device (CIED) insertion. METHODS: An electronic search was performed to identify all relevant studies published from 2000 to 2018. Overall, 15 studies were selected for the analysis comprising 4019 patients with data reported on TR development following ICD or PPM lead placement. Demographic information, perioperative clinical variables, and clinical outcome measures, including pre and postoperative echocardiographic TR grade changes, were extracted and pooled for systematic review. RESULTS: Mean patient age was 69 years [95% CI: 64.62-73.59], and 63% [95% CI: 57-68] were male. Devices implanted included ICD in 57% [95%CI: 43-70] and PPM in 41% [95%CI: 31-52]. The most common indications for pacemaker implantation were sick sinus syndrome in 22% [95% CI: 22-37] and AV block in 21% [95%CI:12-34. The commonest indications for ICD implantation were primary and secondary prevention of sudden cardiac death. Atrial fibrillation was present in 37% [95%CI: 28-46] and congestive heart failure in 15% [95%CI: 2-57]. Baseline distribution of TR grades were as follows: grade 0/1 TR in 89% [95%CI: 82-93], grade 2 TR in 8% [95%CI: 5-13], grade 3 TR in 2% [95%CI: 0-7] and grade 4 TR in 2% [95%CI: 1-4]. Post-procedure, grade 0/ 1 TR decreased to 68% [95% CI: 51-81] (p < 0.01), grade 2 TR increased to 21% [15-28] (p < 0.01), grade 3 TR increased to 13% [95%CI: 5-32] (p = 0.02), and grade 4 TR increased to 7% [95%CI: 5-9] (p < 0.01). CONCLUSION: ICD and PPM lead placement is associated with increased TR post-procedure. Further studies are warranted to evaluate changes in TR grade in the long term.

Outcomes of surgical treatment for carcinoid heart disease: A systematic review and meta-analysis.

BACKGROUND: Carcinoid heart disease (CaHD) develops from vasoactive substances released by neuroendocrine tumors, which can cause significant patient morbidity and mortality without surgical intervention. We performed a systematic review and meta-analysis to elucidate granular perioperative details and long-term outcomes in these patients. METHODS: Electronic search of Ovid, Scopus, Cumulative Index of Nursing and Allied Health Literature, and Cochrane Controlled Trials Register was performed to examine surgical treatment of carcinoid disease. Nine articles comprising 416 patients were selected. Study-level data were extracted and pooled for meta-analysis. RESULTS: Mean patient age was 63 years (95% confidence interval, 57-70) with 53% (95% confidence interval, 46-61) of patients being male. In addition, 75% (95% confidence interval, 54-96) of neuroendocrine tumors originated from the small bowel or colon and 98% (95% confidence interval, 93-100) had liver metastases. Right heart failure was present in 48% (95% confidence interval, 14-81). Moderate or severe regurgitation was present in 97% (95% confidence interval, 95-99) of tricuspid and 72% (95% confidence interval, 58-83) of pulmonary valves. In addition, 99% (95% confidence interval, 98-100) of tricuspid and 59% (95% confidence interval, 38-79) of pulmonary valves were replaced. Bioprosthetic valves were used in 80% (95% confidence interval, 68-93) of tricuspid positions. Mean hospital duration of stay was 16 days (95% confidence interval, 7-25). Thirty-day mortality was 9% (95% confidence interval, 6-12). Mean follow-up was 25 months (95% confidence interval, 11-39). Median survival was 3 years (95% confidence interval, 2.5-3.5). CONCLUSION: For patients >18 years of age, surgical treatment of carcinoid heart disease can be performed with a reasonable safety profile. However, overall survival appears to have ongoing effects of the primary disease.

Evaluation of Endovascular Intervention for Tracheo-Innominate Artery Fistula: A Systematic Review.

BACKGROUND: While the standard of care for suspected tracheo-innominate artery fistula (TIF) necessitates sternotomy, perioperative mortality remains high. Endovascular interventions have been attempted, but reports have been anecdotal. The aim of this systematic review was to evaluate the outcomes of endovascular management of TIF by pooling the existing evidence. METHODS: An electronic database search of Ovid MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Controlled Trials Register was performed to identify all studies examining endovascular treatment of TIF. Patients greater than 14 years of age who underwent endovascular intervention for TIF were included. 25 studies consisting of 27 patients met the inclusion criteria. RESULTS: 48.1% (13/27) of patients were male and median age was 39.0 [IQR 16.0, 47.5] years. Tracheostomy was present in 96.3% (26/27) of cases. Median duration from tracheostomy to TIF presentation was 2.2 months [0.5, 42.5]. On presentation, 84.6% (22/26) had tracheal hemorrhage, and 22.8% (6/27) were hemodynamically unstable. 96.3% (26/27) underwent covered stent graft placement while 1 patient (3.8%) had coil embolization. 18.5% (5/27) of patients required repeat endovascular intervention for recurrent bleeding, while 11.1% (3/27) required rescue sternotomy. Median hospital length of stay was 30 days [16.0, 46.5], and overall mortality was 29.6% (8/27) with a median follow-up time of 5 months [1.2, 11.5]. CONCLUSION: While uncommon, endovascular treatment of TIF may be a feasible alternative to sternotomy. The approach may be useful in those who are unable to undergo surgery or are likely to have adhesions from prior chest operations.

Electromagnetic interference between implantable cardiac devices and continuous-flow left ventricular assist devices: a review.

Many patients with continuous-flow left ventricular assist devices (CF-LVAD) have other, co-existing implantable cardiac devices. While such devices often function appropriately, there is potential for electromagnetic interference (EMI). A literature review was performed to identify cases of EMI between CF-LVAD and other implanted cardiac devices to better understand their etiology, outcomes, and the strategies used to overcome such interference. The cases identified included interference between CF-LVAD and pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy. The EMI reported in the current literature can be broken down into two general categories: interference leading to difficulty establishing telemetry and interference leading to impaired electrical signal sensing. Such interference led to inappropriate shock delivery in some cases. The type of interference, and thus treatments, differed and were device dependent. The strategies employed to reduce interference included metal shielding, physical manipulation to increase the distance between devices, and even exchange of the implanted device with another brand of the same class. To avoid such EMI in the future, physicians must be aware of the reported interference between certain devices, and manufacturers must work more closely to increase the compatibility of implanted cardiac devices.

Continuous-flow LVAD exchange to a different pump model: Systematic review and meta-analysis of the outcomes.

Despite improved outcomes of modern continuous-flow left ventricular assist devices (CF-LVADs), device exchange is still needed for various indications. While the majority of CF-LVADs are exchanged to the same model, exchange to a different pump model is occasionally warranted. In this meta-analysis, we sought to consolidate the existing evidence to better elucidate the indications and outcomes in these cases. A comprehensive systematic search of adult patient cohorts who underwent CF-LVAD exchange to a different CF-LVAD model was performed. Study-level data from 10 studies comprising 98 patients were extracted and pooled for analysis. Mean patient age was 58 (95% CI: 48-65) and 81% were male. Indication for initial CF-LVAD was ischemic cardiomyopathy in 45% (34-57). Initial device was HeartMate II LVAD (HMII) in 93 (94.9%) and HeartWare HVAD (HW) in 5 (5.1%) patients. After mean CF-LVAD support time of 18.8 (15.2-22.4) months, exchange indications included thrombosis in 71% (43-89), infection in 21% (8-47) and device malfunction in 12% (7-21). HMII to HW exchange occurred in 53 (54.1%) patients, HMII to HeartMate III (HM3) in 32 (32.7%), and HM II to either HW or HM3 in 13 (13.2%) patients. Postoperatively, right ventricular assist device was required in 16% (8-32). Overall, 20% (8-40) of patients experienced a stroke, while HW patients had a significantly higher stroke incidence than HM3 patients (HW: 21% (8-47) vs. HM3: 5% (1-24), P < .01). Overall 30-day mortality was 10% (6-17), while HW had a significantly worse 30-day mortality than HM3 (HW: 13% (7-24) vs. HM3: 5% (1-24), P = .03). Following device exchange from a different CF-LVAD model, HM3 is associated with lower stroke and higher survival when compared to HW.

Machine perfusion of donor organs for transplantation.

The ever-widening gap between organ supply and demand has resulted in an organ shortage crisis that affects patients all over the world. For decades, static cold storage (SCS) was the gold standard preservation strategy because of its simplicity and cost-effectiveness, but the rising unmet demand for donor organ transplants has prompted investigation into preservation strategies that can expand the available donor pool. Through ex vivo functional assessment of the organ prior to transplant, newer methods to preserve organs such as perfusion-based therapy can potentially expand the available organ pool. This review will explain the physiologic rationale for SCS before exploring the advantages and disadvantages associated with the two broad classes of preservation strategies that have emerged to address the crisis: hypothermic and normothermic machine perfusion. A detailed analysis of how each preservation strategy works will be provided before investigating the current status of clinical data for each preservation strategy for the kidney, liver, pancreas, heart, and lung. For some organs there is robust data to support the use of machine perfusion technologies over SCS, and in others the data are less clear. Nonetheless, machine perfusion technologies represent an exciting frontier in organ preservation research and will remain a crucial component of closing the gap between organ supply and recipient demand.

Utilization of extracorporeal life support for diffuse alveolar damage and diffuse alveolar hemorrhage: A systematic review.

Modern extracorporeal life-support (ECLS) technology has been successfully utilized to treat patients with diffuse alveolar damage (DAD) and diffuse alveolar hemorrhage (DAH); however, reports in the literature remain scarce. We sought to pool existing evidence to better characterize ECLS use in these patients. An electronic search was conducted to identify all studies in the English literature reporting the use of ECLS for DAD/DAH. Thirty-two articles consisting of 38 patients were selected, and patient-level data were extracted and pooled for analysis. Median patient age was 36 [IQR: 27, 48] years, and the majority (63.2%) were female. Most common etiological factors included granulomatosis with polyangiitis (8/38, 21.1%), systemic lupus erythematosus (8/38, 21.1%), Goodpasture's syndrome (4/38, 10.5%), and microscopic polyangiitis (4/38, 10.5%). Immunologic markers included anti-neutrophil cytoplasmic antibody (ANCA) in 15/38 (39.5%), anti-nuclear antibody (ANA) in 6/38 (15.8%), and anti-glomerular basement membrane (anti-GBM) antibodies in 4/38 (10.5%). DAH was present in 32/38 (84.2%) of cases and DAD without evidence of DAH was present in 6/38 (15.8%) of cases. ECLS strategies included extracorporeal membrane oxygenation of veno-venous type (VV-ECMO) in 28/38 (73.7%), veno-arterial type (VA-ECMO) in 5/38 (13.2%), and one case of right ventricular assist device with oxygenator (RVAD-ECMO). Heparin was utilized in 18/38 (47.4%) of cases with no difference in use between DAH versus no DAH (P = .46) or VA- versus VV-ECLS (P = 1). Median duration of ECLS was 10 [5, 14] days. Pre- versus post-ECLS comparison of blood gases showed improvement in median PaO2 (49 [45, 59] mm Hg vs. 80 [70, 99] mm Hg, P < .001), PaO2:FiO2 ratio (48.2 [41.4, 54.8] vs. 182.0 [149.4, 212.2], P < .01), and pulse oximetry values (76% [72, 80] vs. 96% [94, 97], P = .086). Overall, 94.7% (36/38) of patients survived to decannulation while 30-day mortality was 10.5% (4/38) with no differences between VA- and VV-ECMO (P = 1 and P = .94, respectively). DAD/DAH occurs in a younger, predominantly female population, and tends to be associated with systemic autoimmune processes. ECLS, independent of its type, appears to result in favorable short-term survival.