Outcomes Following Lung Transplant for COVID-19-Related Complications in the US

Importance

The COVID-19 pandemic led to the use of lung transplant as a lifesaving therapy for patients with irreversible lung injury. Limited information is currently available regarding the outcomes associated with this treatment modality.

Objective

To describe the outcomes following lung transplant for COVID-19-related acute respiratory distress syndrome or pulmonary fibrosis.

Design, Setting, and Participants

In this cohort study, lung transplant recipient and donor characteristics and outcomes following lung transplant for COVID-19-related acute respiratory distress syndrome or pulmonary fibrosis were extracted from the US United Network for Organ Sharing database from March 2020 to August 2022 with a median (IQR) follow-up period of 186 (64-359) days in the acute respiratory distress syndrome group and 181 (40-350) days in the pulmonary fibrosis group. Overall survival was calculated using the Kaplan-Meier method. Cox proportional regression models were used to examine the association of certain variables with overall survival.

Exposures

Lung transplant following COVID-19-related acute respiratory distress syndrome or pulmonary fibrosis.

Main Outcomes and Measures

Overall survival and graft failure rates.

Results

Among 385 included patients undergoing lung transplant, 195 had COVID-19-related acute respiratory distress syndrome (142 male [72.8%]; median [IQR] age, 46 [38-54] years; median [IQR] allocation score, 88.3 [80.5-91.1]) and 190 had COVID-19-related pulmonary fibrosis (150 male [78.9%]; median [IQR] age, 54 [45-62]; median [IQR] allocation score, 78.5 [47.7-88.3]). There were 16 instances of acute rejection (8.7%) in the acute respiratory distress syndrome group and 15 (8.6%) in the pulmonary fibrosis group. The 1-, 6-, and 12- month overall survival rates were 0.99 (95% CI, 0.96-0.99), 0.95 (95% CI, 0.91-0.98), and 0.88 (95% CI, 0.80-0.94) for the acute respiratory distress syndrome cohort and 0.96 (95% CI, 0.92-0.98), 0.92 (95% CI, 0.86-0.96), and 0.84 (95% CI, 0.74-0.90) for the pulmonary fibrosis cohort. Freedom from graft failure rates were 0.98 (95% CI, 0.96-0.99), 0.95 (95% CI, 0.90-0.97), and 0.88 (95% CI, 0.79-0.93) in the 1-, 6-, and 12-month follow-up periods in the acute respiratory distress cohort and 0.96 (95% CI, 0.92-0.98), 0.93 (95% CI, 0.87-0.96), and 0.85 (95% CI, 0.74-0.91) in the pulmonary fibrosis cohort, respectively. Receiving a graft from a donor with a heavy and prolonged history of smoking was associated with worse overall survival in the acute respiratory distress syndrome cohort, whereas the characteristics associated with worse overall survival in the pulmonary fibrosis cohort included female recipient, male donor, and high recipient body mass index.

Conclusions and Relevance

In this study, outcomes following lung transplant were similar in patients with irreversible respiratory failure due to COVID-19 and those with other pretransplant etiologies.

Transthoracic fundoplication using the Belsey Mark IV technique versus Nissen fundoplication: A systematic review and meta-analysis

BACKGROUND

Nissen fundoplication is considered the cornerstone surgical treatment for hiatal hernia repair. Belsey Mark IV (BMIV) transthoracic fundoplication is an alternative approach that is rarely utilized in today's minimally invasive era. This study aims to summarize the safety and efficacy of BMIV and to compare it with Nissen fundoplication.

METHODS

We searched MEDLINE, Scopus, and Cochrane Library databases for single arm and comparative studies published by March 31st, 2022, according to PRISMA statement. Inverse-variance weights were used to estimate the proportion of patients experiencing the studied outcome and random-effects meta-analyses were performed.

RESULTS

17 studies were identified, incorporating 2136 and 638 patients that underwent Belsey Mark IV or Nissen fundoplication, respectively. A total of 13.8% (95% CI: 9.6-18.6) of the patients that underwent fundoplication with the BMIV technique had non-resolution of their symptoms and 3.5% (95% CI: 2.0-5.4) required a reoperation. Overall, 14.8% (95% CI: 9.5-20.1) of the BMIV arm patients experienced post-operative complications, 5.0% (95% CI: 2.0-9.0) experienced chronic postoperative pain and 6.9% (95% CI: 3.1-11.9) had a hernia recurrence. No statistically significant difference was observed between Belsey Mark IV and Nissen fundoplication in terms of post-interventional non-resolution of symptoms (odds ratio [OR]: 1.49 [95% Confidence Interval (95%CI):0.6-4.0]; p = 0.42), post-operative complications (OR:0.83, 95%CI: 0.5-1.5, p = 0.54) and in-hospital mortality (OR:0.69, 95%CI: 0.13-3.80, p = 0.67). Belsey Mark IV arm had significantly lower reoperation rates compared to Nissen arm (OR:0.28, 95%CI: 0.1-0.7, p = 0.01).

CONCLUSIONS

BMIV fundoplication is a safe and effective but technically challenging. The BMIV technique may offer benefits to patients compared to the laparoscopic Nissen fundoplication. These benefits, however, are challenged by the increased morbidity of a thoracotomy.

Postoperative symptom monitoring with ePROs in an academic public hospital

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Background: Postoperative symptom burden is high in surgical oncology patients. Electronic patient-reported outcome (ePRO) remote monitoring systems are rapidly proliferating and have the promise of improving care. However, implementation in diverse practice settings is understudied. More information on ePRO participation may determine addressable barriers. Methods: Patients presenting to the Multidisciplinary Thoracic Oncology Program for surgery were prospectively enrolled. ePROs assessing common postop symptoms and functional impairments were administered via a web-based platform daily for 14 days and then weekly until 3 months post-discharge. Automated reminders were provided by email. Phone calls were made for 2 consecutive missed ePROs. ePRO participation levels were categorized as high (> 80%), medium (50-80%), low (1-49%), and none. Patient characteristics were examined by participation level via Fisher’s exact and Kruskal-Wallis tests. Results: From 2020-2022, 202 patients were recruited to participate, and 113 (56%) agreed. There were no differences in demographics of agreed vs. declined. 99 patients initiated ePROs after discharge. Mean age was 60.5 years (sd 13.4), 37.8% were male, 72.5% were White, and the majority (64%) had lung resection. Patients participated in ePROs for an average of 82 days (sd 24) before discontinuing. Overall, 57.7% (1383/2397) of delivered surveys were completed; response rates were lowest in week 1 (48%) and highest in week 7 (71%). Participation levels are described in Table. Married/partnered patients were significantly more likely to have high levels of participation (p = 0.003), and those who regularly used a computing device almost reached significance (p = 0.057). Age, gender, race, employment, email/internet use, financial status, and quality of life did not vary across ePRO participation levels. Conclusions: Monitoring symptoms with ePROs after discharge from thoracic surgery is feasible in a large academic public hospital. Participation levels in ePROs are lower immediately after discharge, when symptomatic complications drive the highest rates of readmissions. This suggests an opportunity to improve ePRO implementation during the post-acute period when intensive monitoring is desired and in patients who are not partnered or are less frequent device users. As length of stay and readmissions are increasingly targeted for expenditure reduction in academic inpatient settings, it is paramount to design and implement systems to effectively monitor at-risk patients. Clinical trial information: NCT04342260. [Table: see text]

The use of grape juice in the detection of esophageal leaks

Background

Esophagectomies and repair of esophageal perforations are operations used for a variety of clinical indications. Anastomotic leaks are a major post-operative complication after these procedures. At our institution, we routinely use grape juice to detect esophageal leaks in the post-operative setting in addition to other standard imaging modalities. We hypothesize that grape juice can provide similar diagnostic sensitivity and specificity to other modalities for leak detection.

Methods

A retrospective review of all patients who underwent an esophagectomy or repair of esophageal perforations from 2013–2019 by the thoracic surgery service at our institution was performed. All patients underwent a barium swallow study, CT imaging or upper endoscopy, as well as ingesting purple grape juice on post-operative day 5 or greater. Purple grape juice observed in the tube thoracostomy drainage system was identified as a positive esophageal leak.

Results

Sixty-four patients were included in the study period (25% female, 88% white, median age 62 years old). Sixty-three patients had both a barium swallow study and grape juice test, while one patient underwent CT imaging and grape juice study. Grape juice test sensitivity and specificity were found to be 80% and 98.3%, respectively.

Conclusions

This pilot study demonstrates the effectiveness of using grape juice in detecting esophageal leaks after esophageal operations in patients with tube thoracostomies. Grape juice may be cheaper and potentially less morbid than other studies performed to detect esophageal leaks. Further research is needed to justify the increased use of grape juice in patients who undergo esophageal operations.

Donation after circulatory death donors in lung transplantation

Transplantation of any organ into a recipient requires a donor. Lung transplant has a long history of an inadequate number of suitable donors to meet demand, leading to deaths on the waiting list annually since national data was collected, and strict listing criteria. Before the Uniform Determination of Death Act (UDDA), passed in 1980, legally defined brain death in the U.S., all donors for lung transplant came from sudden death victims [uncontrolled Donation after Circulatory Death donors (uDCDs)] in the recipient’s hospital emergency department. After passage of the UDDA, uDCDs were abandoned to Donation after Brain Death donors (DBDs)—perhaps prematurely. Compared to livers and kidneys, many DBDs have lungs that are unsuitable for transplant, due to aspiration pneumonia, neurogenic pulmonary edema, trauma, and the effects of brain death on lung function. Another group of donors has become available—patients with a devastating irrecoverable brain injury that do not meet criteria for brain death. If a decision is made by next-of-kin (NOK) to withdraw life support and allow death to occur by asphyxiation, with NOK consent, these individuals can have organs recovered if death occurs relatively quickly after cessation of mechanical ventilation and maintenance of their airway. These are known as controlled Donation after Circulatory Death donors (cDCDs). For a variety of reasons, in the U.S., lungs are recovered from cDCDs at a much lower rate than kidneys and livers. Ex-vivo lung perfusion (EVLP) in the last decade has had a modest impact on increasing the number of lungs for transplant from DBDs, but may have had a larger impact on lungs from cDCDs, and may be indispensable for safe transplantation of lungs from uDCDs. In the next decade, DCDs may have a substantial impact on the number of lung transplants performed in the U.S. and around the world.

Does routine uniportal thoracoscopy during rib fixation identify more injuries and impact outcomes?

Background

Flail chest and severely displaced rib fractures due to blunt trauma can be associated with intrathoracic injuries. At our institution, two thoracic surgeons perform all surgical stabilization of rib fractures (SSRF): one performs routine uniportal thoracoscopy (R-VATS) at the time of SSRF and the other for only select cases (S-VATS). In this pilot study, we hypothesized that R-VATS at the time of SSRF identifies and addresses intrathoracic injuries not seen on imaging and may impact patient outcomes.

Methods

A retrospective review of all patients who underwent SSRF from 2013–2019 at our institution was performed for severely displaced rib fractures or flail chest. Data collected included demographics, imaging results, treatment strategy, and operative findings.

Results

Ninety-nine patients underwent SSRF. Uniportal thoracoscopy was performed on 69% of these patients. When thoracoscopy was performed, 31 additional injuries were identified. R-VATS identified 23 additional intrathoracic findings at time of thoracoscopy not seen on CT scan compared to 8 findings in the S-VATS group (P=0.367). At 3 months follow-up, one empyema and one diaphragmatic hernia required reoperation—neither of which underwent thoracoscopy at time of SSRF. There were no differences in LOS, operative times, and overall mortality between the SSRF/thoracoscopy and SSRF only groups.

Conclusions

R-VATS at the time of SSRF did not identify a statistically significant greater number of occult intrathoracic injuries compared to S-VATS. R-VATS was not associated with increased operative time, LOS, and mortality. Further study is needed to determine if there is benefit to R-VATS in patients meeting requirements for rib fracture repair.

Trends and Outcomes in Minimally Invasive Surgery for Locally Advanced Non-Small-Cell Lung Cancer With N2 Disease

Few studies examine outcomes by surgical approach in non-small-cell lung cancer (NSCLC) with N2 disease. We examined time trends in surgical approach and outcomes among patients undergoing minimally invasive (MIS, robotic and video-assisted thoracoscopic surgery [VATS]) vs open lobectomy in this patient population. We performed a retrospective analysis of patients from the National Cancer Database diagnosed with clinical Stage IIIA-N2 NSCLC from 2010 to 2016. We examined the yearly proportion of MIS vs open resections. Multivariable regression was used to assess the association of surgical approach with length of stay, unplanned readmissions, 30-day and 90-day mortality. Multivariable Cox proportional hazards modeling was used to assess the association of surgical approach with 5-year overall mortality. We identified 5741 patients who underwent lobectomy for Stage IIIA-N2 NSCLC (459 robotic, 1403 VATS, 3879 open). From 2010 to 2016, the proportion of minimally invasive procedures increased from 20% to 45%. MIS patients, on average, stayed 1 day less in the hospital (95% confidence interval [CI] 0.7, 1.5) and had lower odds of 90-day (odds ratio [OR] 0.74; 95% CI 0.54, 0.99) and 5-year mortality (OR 0.82; 95% CI 0.75, 0.91), compared to open resections. There was no difference in odds of readmission by surgical approach (OR 0.97; 95% CI 0.71, 1.33). Among MIS procedures, robotic resections had lower odds of 90-day mortality (OR 0.42; 95% CI 0.18, 0.97) than VATS. Among patients undergoing lobectomy for locally advanced N2 NSCLC robotic and VATS techniques appear safe and effective compared to open surgery and may offer short- and long-term advantages.

Novel Modification of HeartMate 3 Implantation

We have modified the HeartMate 3 (Abbott, Abbott Park, IL) implantation technique to better suit our patient population. This modification optimizes the placement of the HeartMate 3 sewing cuff and allows passage of the suture transmurally from endocardium to epicardium in a "cut then sew" technique. We believe this affords a superior seal and protection from tearing friable myocardium.

Omental Flap Provides Definitive Management for Pediatric Patient With Multiple Tracheoesophageal Fistula Recurrences

A term female infant with tracheoesophageal fistula (TEF) and esophageal atresia (EA) underwent primary operative repair that failed with 3 TEF recurrences, which all presented with feeding and respiratory issues. Recurrences were managed with reoperation and an interpositional flap of pleura and a flap of intercostal muscle on 2 separate occasions. The third recurrence was managed with complete dissection of the esophagus prior to the division of the fistula and the interposition of an omental flap between the esophageal and tracheal repair. We present the use of a viable omental flap and complete esophageal mobilization to prevent subsequent TEF recurrences and avoid the additional morbidity of reconstructive surgery.

Incidence and clinical relevance of non-small cell lung cancer lymph node micro-metastasis detected by staging endobronchial ultrasound-guided transbronchial needle aspiration

Background

Approximately twenty percent of lymph node (LN) negative non-small cell lung cancer (NSCLC) patients who undergo curative intent surgery have pan-cytokeratin immunohistochemistry (IHC)-detectable occult micro-metastases (MMs) in resected LNs. The presence of the MMs in NSCLC is associated worsened outcomes. As a substantial proportion of NSCLC LN staging is conducted using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), we sought to determine the frequency of detection of occult MMs in EBUS-TBNA specimens and to evaluate the impact of MMs on progression-free and overall survival.

Methods

We performed retrospective IHC staining for pan-cytokeratin of EBUS-TBNA specimens previously deemed negative by a cytopathologist based on conventional hematoxylin and eosin staining. The results were correlated with clinical variables, including survival outcomes.

Results

Of 887 patients screened, 44 patients were identified meeting inclusion criteria with sufficient additional tissue for testing. With respect to the time of the EBUS-TBNA procedure, 52% of patients were clinical stage I, 34% clinical stage II, and clinical 14% stage IIIa NSCLC. Three patients (6.8%) were found to have cytokeratin positive MMs. All 3 MMs detected were at N2 LN stations. The presence of MMs was associated with significantly decreased progression-free (median 210 vs. 1,293 days, P=0.0093) and overall survival (median 239 vs. 1,120 days, P=0.0357).

Conclusions

Occult LN MMs can be detected in EBUS-TBNA specimens obtained during staging examinations and are associated with poor clinical outcomes. If prospectively confirmed, these results have significant implications for EBUS-TBNA specimen analyses and possibly for the NSCLC staging paradigm.

Rapid on-site pathologic evaluation does not increase the efficacy of endobronchial ultrasonographic biopsy for mediastinal staging

BACKGROUND

Endobronchial ultrasonography with transbronchial needle aspiration (EBUS-TBNA) has been shown to be equivalent to mediastinoscopy in lung cancer staging for mediastinal node involvement. Rapid on-site evaluation (ROSE) to determine the adequacy of nodal sampling has been claimed to be beneficial.

METHODS

A retrospective evaluation was performed in 170 patients who underwent EBUS-TBNA from July 2008 to May 2011. The patients were classified as having either high or low pretest probability for mediastinal disease based on history and radiographic imaging. ROSE was compared with the final pathology reports based on slides and cell blocks.

RESULTS

One hundred thirty-one (77%) patients were classified as being in the high pretest cohort based on clinical staging. Of these, 101 (77%) patients had adequate tissue sampling based on ROSE, with 70 (69%) patients having positive mediastinal disease. In the 30 (23%) patients who had inadequate tissue by ROSE, the final analysis of all the prepared slides and cell blocks allowed for a diagnosis in all but 8 patients. The sensitivity and specificity of ROSE in the high pretest probability cohort were 89.5% and 96.4%, respectively, whereas the overall sensitivity and specificity of EBUS-TBNA was 92.1% and 100%, respectively. Despite having inadequate tissue on ROSE in 30 of 131 patients, sufficient tissue was available on final analysis for diagnosis in 22 of 30 patients.

CONCLUSIONS

ROSE does not impact clinical decision making if a thorough mediastinal staging using EBUS is performed. Despite inadequate tissue sampling assessment by ROSE, a final diagnosis was made in most patients, potentially avoiding an additional surgical procedure to prove mediastinal disease.

Differential pathogenesis of lung adenocarcinoma subtypes involving sequence mutations, copy number, chromosomal instability, and methylation

Background

Lung adenocarcinoma (LAD) has extreme genetic variation among patients, which is currently not well understood, limiting progress in therapy development and research. LAD intrinsic molecular subtypes are a validated stratification of naturally-occurring gene expression patterns and encompass different functional pathways and patient outcomes. Patients may have incurred different mutations and alterations that led to the different subtypes. We hypothesized that the LAD molecular subtypes co-occur with distinct mutations and alterations in patient tumors.

Methodology/Principal Findings

The LAD molecular subtypes (Bronchioid, Magnoid, and Squamoid) were tested for association with gene mutations and DNA copy number alterations using statistical methods and published cohorts (n = 504). A novel validation (n = 116) cohort was assayed and interrogated to confirm subtype-alteration associations. Gene mutation rates (EGFR, KRAS, STK11, TP53), chromosomal instability, regional copy number, and genomewide DNA methylation were significantly different among tumors of the molecular subtypes. Secondary analyses compared subtypes by integrated alterations and patient outcomes. Tumors having integrated alterations in the same gene associated with the subtypes, e.g. mutation, deletion and underexpression of STK11 with Magnoid, and mutation, amplification, and overexpression of EGFR with Bronchioid. The subtypes also associated with tumors having concurrent mutant genes, such as KRAS-STK11 with Magnoid. Patient overall survival, cisplatin plus vinorelbine therapy response and predicted gefitinib sensitivity were significantly different among the subtypes.

Conclusions/ Significance

The lung adenocarcinoma intrinsic molecular subtypes co-occur with grossly distinct genomic alterations and with patient therapy response. These results advance the understanding of lung adenocarcinoma etiology and nominate patient subgroups for future evaluation of treatment response.

Abstract 4839: Lung cancer patients exhibit a genomewide chromosomal instability and DNA methylation correlation which varies by expression subtype

Introduction: Lung cancer is a deadly disease, which manifests gross DNA alterations. Chromosome instability (CIN) and DNA methylation (DM) instability are important DNA alteration processes that contribute to the initiation and progression of lung cancer. Considering that DNA replication and methylation maintenance are coordinated, we hypothesized that CIN and DM may be coordinated in the etiology of lung cancer patients.

Methods: A cohort of 63 patients with surgically-resected lung tumors was collected. DNA copy number was measured by Affymetrix 250K_StyI microarrays. DNA methylation was measured by the MSNP assay, which involves comparing the copy number of HpaII (methylation sensitive) digested DNA to undigested DNA (Yuan, 2006). The sample genomewide CIN score was the median of chromosome arm absolute copy numbers. The sample genomewide DNA methylation score was the median of the percent methylation across all probes. mRNA expression was measured by Agilent 44K microarrays.

Results: CIN and DM varied substantially over lung cancers. Histological classes did not differ in CIN or DM. Lung cancer mRNA expression subtypes (described in Hayes et al., J Clin Oncol, 2006 and Wilkerson et al., Clin Cancer Res 2010) were significantly different in CIN (P<0.05) with the magnoid adenocarcinoma, classical squamous cell carcinoma (SCC), and basal SCC subtypes having the largest CIN scores. DM was also significantly different between expression subtypes (P<0.05), with the magnoid adenocarcinoma and the classical SCC having the largest DM scores. CIN and DM were significantly positively correlated (0.37; P<0.01), indicating that the most copy number disrupted genomes were also the most DNA hypermethylated. To evaluate the combined effect of these alterations, a combined CIN and DM (CIN+DM) standardized score was evaluated. Histological classes did not differ in CIN+DM. Expression subtypes were significantly different in CIN+DM (P<0.01) with the magnoid adenocarcinoma subtype and the classical SCC subtype exhibiting the largest CIN+DM scores. Patients with distant recurrences had a trend of larger CIN+DM scores than patients with local recurrences or no observed recurrences (P<0.21). An mRNA expression signature based on the CIN+DM score was positively correlated (GSEA, FDR < 0.05) with overexpression of DNA repair pathways, providing corroborating evidence for this DNA alteration phenotype.

Conclusions: Genomewide chromosomal instability and DNA methylation are significantly correlated in lung cancer. These co-occurring DNA alterations are the most extreme in the magnoid adenocarcinoma and classical squamous cell carcinoma subtypes, suggesting the subtypes have evolved differently. These results elucidate new lung cancer etiology and future therapies could be focused on exploiting these DNA alterations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4839. doi:10.1158/1538-7445.AM2011-4839

Variability in defining T1N0 non-small cell lung cancer impacts locoregional failure and survival

BACKGROUND

Locoregional recurrence can occur despite complete anatomic resection of T1N0 non-small cell lung cancer. That may be the result of incomplete resection or inaccurate staging. We assessed the impact of extent of nodal staging on the rate of locoregional failure and patient survival.

METHODS

The records of 742 patients undergoing lobectomy, bilobectomy, or pneumonectomy for non-small cell lung cancer from 1996 to 2006 were reviewed. Operative reports and pathology reports were reviewed for the number of lymph nodes and the anatomic nodal stations examined. The Kaplan-Meier method was applied to analyze recurrence-free survival.

RESULTS

A total of 119 patients with pathologically staged Ia lung cancer were identified. Histology type included 61% (n = 73) adenocarcinoma, 27% (n = 32) squamous cell cancer, and 12% (n = 14) other. Median age was 65 years (range, 34 to 88). Mean follow-up duration was 40 months (median 47; range, 1 to 121). Locoregional recurrence occurred in 20% (n = 18). The N2 nodal stations were examined in 94% (n = 112). At least one defined N1 nodal station was examined in 70% (n = 83). Station undefined N1 nodes were examined in 27% (n = 32), and no N1 nodes were examined in 3% (n = 4). Median number of N1 lymph nodes analyzed was 5 (range, 0 to 18). The locoregional recurrence rate was 14% (12 of 83) for patients with a defined N1 station node versus 31% (11 of 36) for patients in whom there were undefined N1 nodes (p = 0.03). Similar differences were seen in disease-free survival, 78.2% versus 62.6%, respectively (p = 0.06).

CONCLUSIONS

Despite anatomic resection of stage Ia lung cancer and uniform analysis of N2 nodal stations, a high rate of locoregional recurrence occurs. Imprecise staging of N1 lymph nodes may contribute to the understaging and undertreatment of patients with early stage lung cancer.

Peak oxygen consumption and long-term all-cause mortality in nonsmall cell lung cancer

BACKGROUND

Identifying strong markers of prognosis is critical to optimize treatment and survival outcomes in patients with nonsmall cell lung cancer (NSCLC). The authors investigated the prognostic significance of preoperative cardiorespiratory fitness (peak oxygen consumption [VO(2peak)]) among operable candidates with NSCLC.

METHODS

By using a prospective design, 398 patients with potentially resectable NSCLC enrolled in Cancer and Leukemia Group B 9238 were recruited between 1993 and 1998. Participants performed a cardiopulmonary exercise test to assess VO(2peak) and were observed until death or June 2008. Cox proportional models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO(2peak) tertiles (<0.96 of 0.96-1.29/>1.29 L/min⁻¹) with adjustment for age, sex, and performance status.

RESULTS

Median follow-up was 30.8 months; 294 deaths were reported during this period. Compared with patients achieving a VO(2peak) <0.96 L/min⁻¹, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% confidence interval [CI], 0.46-0.88) for a VO(2peak) of 0.96 to 1.29 L/min⁻¹, and 0.56 (95% CI, 0.39-0.80) for a VO(2peak) of >1.29 L/min⁻¹) (P(trend) = .0037). The corresponding HRs for resected patients were 0.66 (95% CI, 0.46-0.95) and 0.59 (95% CI, 0.40-0.89) relative to the lowest VO(2peak) category (P(trend) = .0247), respectively. For nonresected patients, the HRs were 0.78 (95% CI, 0.34-1.79) and 0.39 (95% CI, 0.16-0.94) relative to the lowest category (P(trend) = .0278).

CONCLUSIONS

VO(2peak) is a strong independent predictor of survival in NSCLC that may complement traditional markers of prognosis to improve risk stratification and prognostication.

Activation of fibrinolytic pathways is associated with duration of supraceliac aortic cross-clamping

PURPOSE

The cause of the coagulopathy seen with supraceliac aortic cross-clamping (SC AXC) is unclear. SC AXC for 30 minutes results in both clotting factor consumption and activation of fibrinolytic pathways. This study was undertaken to define the hemostatic alterations that occur with longer intervals of SC AXC.

METHODS

Seven pigs underwent SC AXC for 60 minutes. Five pigs that underwent infrarenal aortic cross-clamping (IR AXC) for 60 minutes and 11 pigs that underwent SC AXC for 30 minutes served as controls. No heparin was used. Blood samples were drawn at baseline, 5 minutes before release of the aortic clamp, and 5, 30, and 60 minutes after unclamping. Prothrombin time, partial thromboplastin time, platelet count, and fibrinogen concentration were measured as basic tests of hemostatic function. Thrombin-antithrombin complexes were used to detect the presence of intravascular thrombosis. Fibrinolytic pathway activation was assessed with levels of tissue plasminogen activator antigen and tissue plasminogen activator activity, plasminogen activator inhibitor-1 activity, and alpha2-antiplasmin activity. Statistical analysis was performed with the Student t test and repeated measures of analysis of variance.

RESULTS

Prothrombin time, partial thromboplastin time, and platelet count did not differ between groups at any time. Fibrinogen concentration decreased 5 minutes (P =.005) and 30 minutes (P =.006) after unclamping in both SC AXC groups, but did not change in the IR AXC group. Thrombin-antithrombin complexes increased in both SC AXC groups, but were not significantly greater than in the IR AXC group. SC AXC for both 30 and 60 minutes produced a significant increase in tissue plasminogen activator antigen during clamping and 5 minutes after clamping. This increase persisted for 30 and 60 minutes after clamp release in the 60-minute SC AXC group. Tissue plasminogen activator activity, however, increased only in the 60-min SC AXC group during clamping (P =.02), and 5 minutes (P =.05) and 30 minutes (P =.06) after unclamping, compared with both control groups.

CONCLUSIONS

Thirty and 60 minutes of SC AXC results in similar degrees of intravascular thrombosis and fibrinogen depletion. Although SC AXC for both 30 and 60 minutes leads to activation of fibrinolytic pathways, only 60 minutes of SC AXC actually induces a fibrinolytic state. Fibrinolysis appears to be an important component of the coagulopathy associated with SC AXC, and is related to the duration of aortic clamping.

CLINICAL RELEVANCE

The coagulopathy frequently associated with thoracoabdominal aortic aneurysm repair is thought to revolt visceral ischemia-reperfusion. The nature of this coagulopathy is controversial. The current study demonstrates that the major hemostatic alteration associated with supraceliac aortic cross-clamping is activation of fibrinolytic pathways. The magnitude of this fibrinolytic response is directly related to the duration of supraceliac aortic occlusion. Future efforts to treat this coagulopathy may well include judicious use of autofibrinolytic agents.

Hemodynamic unloading of the failing left ventricle using an arterial-to-arterial extracorporeal flow circuit

We tested the hypothesis that creation of a constant-flow extracorporeal circuit between the proximal and distal aorta will unload the failing left ventricle. Studies were performed in 14 heart failure dogs produced by intracoronary microembolizations. An extracorporeal circuit incorporating a diagonal pump was placed between a femoral and a carotid artery, with flow directed to the carotid. Hemodynamic measurements were made with the pump delivering 0.25 L/min through the circuit for 4 hours (active group). Measurements obtained from 8 sham-operated heart failure dogs were used for comparison (control group). Heart rate, peak left ventricular systolic pressure, left ventricular end-diastolic pressure, end-diastolic volume, end-systolic volume, and ejection fraction were measured at baseline and at 30, 60, 120, and 240 minutes. There were no differences in any of the hemodynamic values during the 4 hours of follow-up in the control group. In the active group, there was no effect on heart rate or peak systolic pressure, but reductions between baseline and 240 minutes were observed in left ventricular end-diastolic pressure (15 +/- 1 vs 6 +/- 1 mm Hg, p < 0.05), end-diastolic volume (61 +/- 3 vs 50 +/- 3 mL, p < 0.05), and end-systolic volume (44 +/- 2 vs 32 +/- 2 mL, p < 0.05), and an increase in ejection fraction (28 +/- 2 vs 37% +/- 2%, p < 0.05). Acute use of this artery-to-artery extracorporeal system effectively unloads the failing left ventricle. The potential benefits of this approach on long-term myocardial recovery in heart failure require further investigation.

Long-term outcome after coronary artery bypass grafting in patients with severe left ventricular dysfunction

BACKGROUND

The aim of this study was to define the potential for long-term survival with severe left ventricular dysfunction after coronary bypass and to quantify any improvement in overall functional status.

METHODS

Left ventricular dysfunction was confirmed preoperatively and the long-term survival and functional outcome after bypass was determined by follow-up studies obtained during the span of a decade.

RESULTS

From 1/1990 to 12/1999, 86 patients with severe left ventricular dysfunction (mean ejection fraction, 0.18 +/- 0.03; range, 0.10 to 0.20) underwent coronary artery bypass grafting. There were 10 perioperative deaths (11% mortality). The mean survival was 55 months (standard deviation +/- 34 months; range, 2 to 141 months) with an actual 5-year survival rate of 59% (actuarial 5-year 65%, 10-year 33%). Echocardiography obtained between 1 and 6 months, 6 months and 1 year, 1 and 2 years, 2 and 4 years, 4 and 6 years, and 6 and 11 years showed the ejection fraction improved to 0.29 +/- 0.08 (p < 0.001), 0.31 +/- 0.14 (p < 0.002), 0.35 +/- 0.08 (p < 0.001), 0.27 +/- 0.10 (p = 0.002), 0.36 +/- 0.14 (p = 0.004), and 0.30 +/- 0.11 (p = 0.004), respectively. At 1 to 6 months, 6 months to 1 year, and 1 to 2 years, the diastolic left ventricular dimension was unchanged, but the systolic left ventricular dimension decreased significantly from 5.02 +/- 0.77 cm to 4.26 +/- 0.91 cm (p = 0.046), 3.98 +/- 1.43 cm (p = 0.08), and 4.10 +/- 1.14 cm (p = 0.07). The preoperative New York Heart Association classification for all patients improved from 2.8 +/- 0.8 to 1.6 +/- 0.7 (p < 0.001) after a mean of 53 months (standard deviation +/- 34 months).

CONCLUSIONS

Patients with severe left ventricular dysfunction can derive long-term benefit from coronary bypass through improved left ventricular contractility as documented by a significantly decreased systolic left ventricular dimension and increased ejection fraction. Successful bypass is associated with a 59% actual 5-year survival rate and significantly improved New York Heart Association functional class.

Caprine beta-mannosidase: sequencing and characterization of the cDNA and identification of the molecular defect of caprine beta-mannosidosis

The complete sequence of the caprine beta-mannosidase cDNA coding region has been determined, and a mutation that is associated with caprine beta-mannosidosis has been identified. Reverse transcriptase-polymerase chain reactions were performed using primers based on bovine and, later, goat cDNA sequences to produce an overlapping series of amplicons covering the entire coding region. The composite cDNA codes for an 879-amino-acid peptide that has four potential N-glycosylation sites. Comparison of the caprine and bovine cDNAs reveals that 96.3% of the nucleotides and 95.2% of the deduced amino acids are identical. A single-base deletion at position 1398 of the coding sequence was identified in the cDNA isolated from a goat affected with beta-mannosidosis. This deletion results in a shift in the reading frame and a premature termination of translation, yielding a deduced peptide of 481 amino acids. An assay, developed to determine the presence or absence of this mutation, confirmed that animals affected with beta-mannosidosis were homozygous for the mutation and that obligate carriers in a caprine beta-mannosidosis colony were heterozygous. This assay accurately distinguished between mutation carrier and noncarrier goats and was used for prenatal diagnosis using DNA collected from fetal fluids. The assay also confirmed chimerism in a goat with an atypically mild beta-mannosidosis phenotype. Thus, this application enables assessment of the efficacy of engraftment of hematopoietic stem cells after prenatal transfer from donor sources.