Underestimation of mortality following lung volume reduction surgery resulting from incomplete follow-up

Antineutrophil cytoplasmic antibody-associated vasculitis classification by cluster analysis based on clinical phenotypes: a single-center retrospective cohort study

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a group of small vessel inflammatory disorders. Overlapping clinical phenotypes of AAV subgroups continually provoke controversies over their diagnostic and classification criteria.

METHODS

Using the agglomerative hierarchical clustering method, we classified 210 Korean patients diagnosed with AAV into mutually exclusive clusters according to Birmingham Vasculitis Activity Score items, ANCA specificity, sex, and age. We analyzed the resulting clusters' outcomes to investigate the clinical significance of the classification. We proposed a distance-based algorithm of patient assignment and explored its clinically relevant modification.

RESULTS

In total, 116 patients (55%) had microscopic polyangiitis, 53 (25%) had granulomatosis with polyangiitis, and 42 (20%) had eosinophilic granulomatosis with polyangiitis. Our model grouped the patients into five clusters, namely, "limited proteinase 3 (PR3)-ANCA vasculitis," "generalized PR3-ANCA vasculitis," "ANCA-negative vasculitis," "renal-limited vasculitis," and "myeloperoxidase-ANCA vasculitis." Patients clustered under "generalized PR3-ANCA vasculitis" had a higher relapse rate (hazard ratio [HR] = 2.12, P = 0.067). The incidence of end-stage renal disease was higher in patients belonging to the "renal-limited vasculitis" cluster (HR=1.50, P=0.03), and those in the "ANCA-negative vasculitis" cluster experienced a relatively milder clinical course of AAV (mortality = 0).

CONCLUSION

Because the clusters were naturally derived from their distinguished phenotypes and have different clinical courses, our clustering method may be a more clinically relevant classification system for AAV, revealing its phenotypic diversity. We also proposed a simple and intuitive distance-based assignment algorithm, which can be easily modified according to specific clinical needs. Key Points • In this study with a single-center AAV cohort, we showed that AAV can be divided into five distinct subclasses with different disease courses based on the clinical and laboratory features of the patients. • Our study revealed ethnic differences in AAV manifestation and suggests that physicians may need to analyze their own AAV patients to assess the disease status of AAV patients. • We proposed a distance-based cluster membership assignment method that can be clinically modified to fit the specific purpose of grouping patients.

Loss to follow-up after direct-to-implant breast reconstruction

Loss to follow-up is inevitable in retrospective cohort studies, and patients are lost to follow-up after direct-to-implant reconstruction despite annual follow-up recommendation. We analyzed more than 500 patients to analyze the rate of loss to follow-up to plastic surgery and to investigate the factors affecting it. A retrospective review of patients who underwent direct-to-implant reconstruction between July 2008 and August 2016 was performed. Loss to follow-up to plastic surgery was defined as a difference of ≥24 months between the total and plastic surgery follow-up. The rate of loss to follow-up and associated factors including patients' demographics, surgery-related variables, oncological data, and early and late complications were analyzed. Of 631 patients who underwent direct-to-implant reconstruction, 551 patients continued visiting the hospital for breast cancer-related treatment. Of the 527 patients who were eligible for the study, 157 patients (29.8%) were lost to plastic surgery follow-up. Surgery-related variables, early complications, cancer stage, and adjuvant therapies were not significantly different. Younger age was significantly associated with loss to follow-up in univariate analysis. However, logistic regression revealed that a long total follow-up period, distant metastasis, and absence of late elective complications were significant factors contributing to follow-up loss. Late elective complications such as malposition, capsular contracture, and mastectomy flap thinning were more common in the follow-up group (48%) than in the loss to follow-up group (22%). Follow-up loss after direct-to-implant reconstruction was not associated with specific demographic or surgery-related variables, and postoperative courses significantly affected the loss to follow-up.

Participants Attrition in a Longitudinal Study: The Malaysian Cohort Study Experience

The attrition rate of longitudinal study participation remains a challenge. To date, the Malaysian Cohort (TMC) study follow-up rate was only 42.7%. This study objective is to identify the cause of attrition among TMC participants and the measures to curb it. A total of 19,343 TMC participants from Kuala Lumpur and Selangor that was due for follow-up were studied. The two most common attrition reasons are undergoing medical treatment at another government or private health center (7.0%) and loss of interest in participating in the TMC project (5.1%). Those who were inclined to drop out were mostly Chinese, aged 50 years and above, unemployed, and had comorbidities during the baseline recruitment. We have also contacted 2183 participants for the home recruitment follow-up, and about 10.9% agreed to join. Home recruitment slightly improved the overall follow-up rate from 42.7% to 43.5% during the three-month study period.

Changes in arterial oxygenation and self-reported oxygen use after lung volume reduction surgery

RATIONALE

Lung volume reduction surgery (LVRS) is inconsistently reported to improve arterial oxygenation in patients with chronic obstructive pulmonary disease.

OBJECTIVES

We studied the effects of surgery on oxygenation in a large cohort and identified predictors of postoperative oxygenation improvement.

METHODS

We evaluated oxygenation in 1,078 subjects with chronic obstructive pulmonary disease enrolled in the National Emphysema Treatment Trial after LVRS compared with medical control subjects, including arterial blood gases, use of supplemental oxygen during treadmill walking, and self-reported use of oxygen during rest, exertion, and sleep.

MEASUREMENTS AND MAIN RESULTS

Pa(O(2)) breathing room air was equal in medical and surgical subjects at baseline (64.8 vs. 65.0 mm Hg, P = not significant), but lower in medical subjects at 6 months (63.6 vs. 70.0 mm Hg, P < 0.001), 12 months (63.9 vs. 68.7 mm Hg, P < 0.001), and 24 months (62.4 vs. 68.0 mm Hg, P < 0.001). Fewer medical subjects required oxygen for treadmill walking at baseline compared with surgical subjects (46 vs. 53%, P = 0.02). However, more medical subjects required oxygen for this activity at 6 months (49 vs. 33%, P < 0.001), 12 months (50 vs. 36%, P < 0.001), and 24 months (52 vs. 42%, P = 0.02). Self-reported oxygen use was greater in medical than in surgical subjects at 6, 12, and 24 months. Multivariate modeling of preoperative characteristics showed baseline oxygenation status was the best predictor of postoperative oxygenation.

CONCLUSIONS

LVRS increases Pa(O(2)), and decreases treadmill and self-reported use of oxygen for up to 24 months post-procedure. Clinical trial registered with www.clinicaltrials.gov (NCT 00000606).

Characteristics of patients who dropout from a glaucoma clinic

PURPOSE

To find the dropout rate and identify the clinical characteristics of patients who drop out in the first year of follow-up from a glaucoma clinic.

DESIGN

Descriptive hospital-based study at a tertiary hospital eye department.

METHODS

Clinical characteristics of consecutive patients newly diagnosed with glaucoma who dropped out (n=452) were compared with patients who did not drop out (n=295) within 12 months.

RESULTS

The rate of dropout from follow-up was 60.5% within 1 year; 43.1% of the study group dropped out after their first follow-up visit. The dropout rate was high in all age groups, but higher in the age groups 21 to 30 years, 41 to 50 years, and over 70 years. Males had a higher dropout rate than females (78.6% vs. 34.5%). Dropout rate was higher among those with mild/moderate glaucoma than those with severe disease (88.2% vs. 37.2%); those who lived further away from the hospital than those who lived nearer to the hospital (72.5% vs. 40.8%), those who were referred from screening clinics for nonblinding eye disease compared with those referred because of a blinding eye disease (72.2% vs. 58.9%). More patients (63.8%) unsure of their family eye disease history dropped out, compared with 34.3% of those with positive family history of glaucoma and other potentially blinding diseases. More patients who had no systemic disease dropped out, than those with systemic disease (54.6% vs. 39.6%); whereas patients on 2 medications or more had a higher dropout rate than those on less than 2 medications (68.1% vs. 52.1%). Of the study factors, those that were statistically significantly associated with dropping out of follow-up from the glaucoma clinic were age, sex, place of domicile, diagnosis at referral, severity of disease, family history, and polydrug use.

CONCLUSIONS

The dropout rate from this glaucoma clinic in the first year was high (60.5%). Patients who were more likely to dropout were younger patients, male, those who travelled far distances to the clinic, those with mild to moderate glaucoma, those with no family history of blinding eye diseases, and patients taking 2 or more eyedrops. Patients who seem to perceive their problems as not serious dropped out of follow-up. These findings have great implications in planning future studies and intervention to improve the follow-up of glaucoma patients in the study area.

Lung-volume reduction surgery for pulmonary emphysema: Improvement in body mass index, airflow obstruction, dyspnea, and exercise capacity index after 1 year

OBJECTIVES

We hypothesized that lung-volume reduction surgery for pulmonary emphysema would improve body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index, a multidimensional predictor of survival in chronic obstructive pulmonary disease. We also aimed to identify preoperative predictors of improvement in the BODE index.

METHODS

In a prospective cohort study of patients undergoing lung-volume reduction surgery at our center, with the methodology of the National Emphysema Treatment Trial, we compared clinical characteristics before and 1 year after surgery with the Wilcoxon signed rank test. Changes in the BODE index were correlated with preoperative variables with the Spearman correlation coefficient.

RESULTS

Twenty-three patients with predominantly upper-lobe pulmonary emphysema underwent lung-volume reduction surgery (14 by video-assisted thoracoscopic surgery, 9 by median sternotomy). There were no postoperative or follow-up deaths. The BODE index improved from a median of 5 (interquartile range 4-5) before surgery to 3 (interquartile range 2-4) 1 year after surgery (P < .0001). Improvements were seen in the lung function and dyspnea components of the BODE index. Lower preoperative 6-minute walk distance and lower postwalk Borg fatigue scores were each associated with greater improvement in the BODE index after 1 year.

CONCLUSION

Lung-volume reduction surgery for pulmonary emphysema improved the BODE index in patients with predominantly upper-lobe disease. Lower preoperative 6-minute walk distance correlated with greater improvement in the BODE index.

Quality of life after lung volume reduction surgery

The common physiologic and functional variables that quantify limitation in emphysema patients have been the most common outcomes measured after LVRS. Spirometric values and exercise capacity are merely surrogates, however, for their impact on symptoms and QOL in patients with severe emphysema. Because LVRS has been developed as a surgery to palliate disabling symptoms of emphysema, many studies now have included HRQOL outcomes along with the commonly measured physiologic and functional outcomes. Some studies have centered on the QOL as the primary outcome instead of physiologic variables. Many symptom scales and disease-specific and general instruments of HRQOL have been used for evaluating emphysema patients before and after LVRS. Case-control studies and randomized studies have shown a consistent improvement in symptoms related to emphysema and general QOL. These studies validate the use of LVRS as a palliative therapy for selected patients with emphysema. The NETT suggests that this benefit is applicable primarily to patients with an upper lobe-predominant pattern of emphysema or patients with low exercise capacity. Validation or refinement of these criteria depends on the continued contributions of the many investigators performing LVRS.

Outcomes after resection of giant emphysematous bullae

BACKGROUND

Giant emphysematous bullae represent a rare form of emphysematous lung destruction. Surgical resection has traditionally been indicated when there is hyperexpansion of the chest, compromised pulmonary function, and evidence of underlying, relatively normal compressed lung. We review our experience and intermediate-term follow-up after the resection of giant bullae.

METHODS

Forty-three patients underwent resection of giant emphysematous bullae at Barnes-Jewish Hospital between March 1994 and June 2002. All had limiting dyspnea and radiologic evidence of hyperinflated giant bullae compressing adjacent lung parenchyma. Forty-one patients underwent preoperative pulmonary rehabilitation. Twenty-two patients underwent a bilateral procedure and 21 underwent a unilateral procedure. Mean follow-up was 4.5 years.

RESULTS

One early death occurred on postoperative day 20 from heparin-induced thrombocytopenia and pulmonary embolism. Complications included prolonged air leak of more than 7 days in 23 (53%), atrial fibrillation in 5 (12%), postoperative mechanical ventilation in 4 (9%), and pneumonia in 2 (5%). Kaplan-Meier survival at 1, 3, and 5 years was 98%, 92%, and 89%, respectively. Four late deaths occurred at 1.4, 2.8, 3.5, and 5.9 years. Functional measures preoperatively and at 6 months and 3 years postoperatively were a forced expiratory volume in 1 second L (% predicted) of 1.2 +/- 0.6 (34%), 1.9 +/- 0.9 (55%), and 1.5 +/- 0.8 (49%); residual volume L (% predicted) of 5.1 +/- 1.2 (262%), 3.6 +/- 1.2 (154%), and 4.1 +/- 2.2 (209%); 6-minutes walk (ft) of 1230 +/- 361, 1393 +/- 300, and 1271 +/- 423; supplemental O2 used continuously (% patients) of 42%, 9%, and 21%; and O2 used during exercise of 73%, 37%, and 42%, respectively.

CONCLUSIONS

In a contemporary series, giant bullectomy is shown to produce significant immediate functional improvement. This benefit declines with time but persists at least 3 years.

Lung Volume Reduction Surgery in Australia and New Zealand

BACKGROUND

Lung volume reduction surgery (LVRS) has been shown to improve lung function, exercise performance, and quality of life in highly selected individuals with severe emphysema; however, major questions regarding the efficacy and long-term outcomes of LVRS still remain unanswered. Pending the results of large randomized controlled trials (RCTs), the Australian and New Zealand LVRS Database was created to audit local clinical practice and patient outcomes.

AIMS

To review patient selection, surgical activity, and patient outcomes related to LVRS in Australia and New Zealand.

METHODS

Prospective data were voluntarily submitted by hospitals performing LVRS in Australia and New Zealand. Preoperative, surgical, perioperative, and follow-up variables were analyzed.

RESULTS

Data were collected from 15 hospitals regarding 529 patients. Mean age (+/- SD) at surgery was 63 +/- 7 years. Preoperatively, FEV(1) was 29 +/- 9% predicted, total lung capacity (TLC) was 138 +/- 20% predicted, residual volume (RV) was 250 +/- 64% predicted, and 6-min walk (6MW) distance was 327 +/- 111 m. There has been a reduction in the overall number of cases and hospitals performing LVRS since 1999. Improvements in lung function following LVRS (ie, FEV(1) increase of 38%, RV decrease of 27%, TLC decrease of 17%) and exercise capacity (ie, 6MW distance increase of 24%) appear to be maintained for approximately 3 years.

CONCLUSIONS

LVRS continues to be performed in Australia and New Zealand, predominantly in large tertiary teaching hospitals with similar outcomes to those described in the literature. It remains difficult to capture long-term lung function and survival outcomes in this population. Ongoing audit and RCTs are both required to resolve the confusion that still shrouds this procedure.

Long-term outcome of bilateral lung volume reduction in 250 consecutive patients with emphysema

OBJECTIVE

Numerous reports have confirmed the early benefits of lung volume reduction surgery for selected patients with emphysema. This report documents the long-term survival and functional results after lung volume reduction surgery.

METHODS

Between January 1993 and June 2000, a total of 250 consecutive patients underwent bilateral lung volume reduction surgery through median sternotomy at our institution. All patients had disabling dyspnea, thoracic hyperinflation, and a heterogeneous pattern of emphysema with suitable target areas for resection. Preoperative pulmonary rehabilitation was required and post-rehabilitation data were used as the baseline for data analysis. Follow-up ranged from 1.8 to 9.1 years (median 4.4 years).

RESULTS

Prolonged air leaks (>7 days) were the most common complication (45.2%, n = 113). Reexploration rates for air leak and bleeding were 3.2% (n = 8) and 1.2% (n = 3), respectively. Eighteen patients (7.2%) required reintubation and mechanical ventilation. The in-hospital mortality in this series was 4.8% (n = 12). The median length of hospitalization was 9 days (range 4-168 days). Kaplan-Meier survivals after lung volume reduction surgery were 93.6%, 84.4%, and 67.7% at 1, 3, and 5 years, respectively. Eighteen patients (7.2%) have subsequently undergone lung transplantation after a median interval of 4.3 years (range 2.1-6.4 years). Spirometric values, lung volumes, and gas exchange parameters improved after surgery. The forced expiratory volume in 1 second and the residual volume showed statistically significant improvements between preoperative values and each time point of follow-up. Health-related quality of life showed significant postoperative improvement and with time correlated well with the improvement in forced expiratory volume in 1 second.

CONCLUSIONS

Lung volume reduction surgery produces significant functional improvement for selected patients with emphysema. For most of these patients, benefits appear to last at least 5 years.

Complications of lung volume reduction surgery

Lung volume reduction surgery (LVRS) continues to stimulate controversy and spirited discussion. The purpose of the operation is to palliate dyspnea and improve functional status and quality of life for highly selected patients with emphysema. The value of LVRS as a palliative procedure is clearly dependent on the surgeon's ability to minimize the frequency and severity of postoperative complications. This article investigates the sources of morbidity and mortality after LVRS and reports techniques to avoid and manage such complications.

Lung volume reduction: where do we stand?

The concept of lung volume resection (LVR) was introduced in 1995 for the treatment of end-stage emphysema patients utilizing stapled resection through a median stenotomy approach. This article discusses this procedure and the trials that have been instituted. LVR might prove to be a viable alternative treatment modality for selected, end-stage emphysema patients in the future.

Patients at high risk of death after lung-volume-reduction surgery

BACKGROUND

Lung-volume-reduction surgery is a proposed treatment for emphysema, but optimal selection criteria have not been defined. The National Emphysema Treatment Trial is a randomized, multicenter clinical trial comparing lung-volume-reduction surgery with medical treatment.

METHODS

After evaluation and pulmonary rehabilitation, we randomly assigned patients to undergo lung-volume-reduction surgery or receive medical treatment. Outcomes were monitored by an independent data and safety monitoring board.

RESULTS

A total of 1033 patients had been randomized by June 2001. For 69 patients who had a forced expiratory volume in one second (FEV1) that was no more than 20 percent of their predicted value and either a homogeneous distribution of emphysema on computed tomography or a carbon monoxide diffusing capacity that was no more than 20 percent of their predicted value, the 30-day mortality rate after surgery was 16 percent (95 percent confidence interval, 8.2 to 26.7 percent), as compared with a rate of 0 percent among 70 medically treated patients (P<0.001). Among these high-risk patients, the overall mortality rate was higher in surgical patients than medical patients (0.43 deaths per person-year vs. 0.11 deaths per person-year; relative risk, 3.9; 95 percent confidence interval, 1.9 to 9.0). As compared with medically treated patients, survivors of surgery had small improvements at six months in the maximal workload (P= 0.06), the distance walked in six minutes (P=0.03), and FEV1 (P<0.001), but a similar health-related quality of life. The results of the analysis of functional outcomes for all patients, which accounted for deaths and missing data, did not favor either treatment.

CONCLUSIONS

Caution is warranted in the use of lung-volume-reduction surgery in patients with emphysema who have a low FEV1 and either homogeneous emphysema or a very low carbon monoxide diffusing capacity. These patients are at high risk for death after surgery and also are unlikely to benefit from the surgery.