Therapeutic video-assisted thoracoscopic surgical resection of colorectal pulmonary metastases

OBJECTIVE

Careful patient selection is vital when video-assisted thoracoscopic surgical (VATS) therapeutic pulmonary metastasectomy of colorectal carcinoma is considered. Complete resection of all metastatic disease remains a vital concept. We reviewed our VATS experience for therapeutic metastasectomy of peripheral colorectal pulmonary metastases.

METHODS

Over 90 months, therapeutic VATS metastasectomy was accomplished upon 80 patients with colorectal metastases. Thin cut computed tomography (CT) was central in identifying lesions. The mean interval from primary carcinoma to VATS resection was 41 months (1-156 months; median, 33). A solitary lesion was resected in 60 patients and multiple (2-7) lesions resected in 20 patients. Statistics were obtained using the Student's t-test.

RESULTS

No operative mortality or major postoperative complications occurred. The hospital stay was 4.5+/-2. 2 days (range, 1-13). All lesions were resected by VATS, with four conversions to thoracotomy to improve the margins. The mean survival of patients with one lesion was 34.8 months compared with 26.5 months for patients with multiple lesions (P=0.37). The mean survival was 20.5 months when metastases occurred <3 years vs. 28.1 months for >3 years from primary carcinoma resection (P=0.20). Twenty-five (31%) patients are disease free; with a mean interval of 38.7 (3-84; median, 35) months. Sixty-nine percent (55/80) of patients developed a recurrence: 6/80 (8%) local; 19/80 (24%) regional (same hemithorax away from resection); and 30/80 (38%) distant. The overall survival at 1 year was 81.2%, 48.4% at 3 years and 30.8% at 5 years.

CONCLUSIONS

Therapeutic VATS resection of colorectal metastases appears efficacious. Preoperative CT can identify peripheral colorectal metastases amenable to VATS. Conversion to thoracotomy is indicated when none of the lesions identified by CT are found or when clear surgical margins are jeopardized.

Preoperative severity of emphysema predictive of improvement after lung volume reduction surgery: use of CT morphometry

STUDY OBJECTIVE

To determine how the volume and severity of emphysema measured by CT morphometry (CTM) before and after lung volume reduction surgery (LVRS) relates to the functional status of patients after LVRS.

DESIGN

A histologically validated CT algorithm was used to quantify the volume and severity of emphysema in 35 patients before and after LVRS: total lung volume (TLV), normal lung volume (< 6.0 mL gas per gram of tissue), volume of mild/moderate emphysema (ME; 6.0 to 10.2 mL gas per gram of tissue), volume of severe emphysema (> 10.2 mL gas per gram of tissue), surface area/volume (SA/V; meters squared per milliliter), and surface area (SA; meters squared). Outcome parameters included maximal cardiopulmonary exercise (CPX) performance in 21 patients and routine pulmonary function in all patients. We hypothesized that baseline CTM parameters predict response to LVRS and that the change in these parameters may offer insight into mechanisms of improvement.

PATIENTS AND INTERVENTION

Thirty-five patients with severe emphysema who had successful LVRS.

RESULTS

The significant decrease in TLV following LVRS was entirely accounted for by a decrease in severe emphysema. The SA/V and the SA both increased significantly following LVRS. The change in maximal CPX in watts following surgery correlated significantly with baseline values of severe emphysema (r = 0.60), which was collinear with TLV, and SA/V. The change in diffusing capacity of the lung for carbon monoxide revealed a significant positive linear relationship with preoperative severe emphysema (r = 0.37) and a negative relationship with ME (r = -0.37). Change in watts revealed a strong relationship with changes in severe emphysema (r = -0.75) and weaker but significant relationships with change in TLV, ME, SA/V, and SA. Other measures of pulmonary function revealed significant albeit less dominant relationships with baseline CTM and change in these indexes.

CONCLUSION

Using CTM, we have identified a close relationship between baseline severe emphysema, or change in severe emphysema, and the improvement in CPX after LVRS. These observations support a potential role of CTM in future clinical trials for predicting responders to LVRS and identifying mechanisms of improvement.

Laparoscopic repair of giant paraesophageal hernia: 100 consecutive cases

OBJECTIVE

To summarize the authors' laparoscopic experience for paraesophageal hernia (PEH).

SUMMARY BACKGROUND DATA

Laparoscopic antireflux surgery and repair of small hiatal hernias are now routinely performed. Repair of a giant PEH is more complex and requires conventional surgery in most centers. Giant PEH accounts for approximately 5% of all hiatal hernias. Medical management may be associated with a 50% progression of symptoms and a significant death rate. Conventional open surgery has a low death rate, but complications are significant and return to routine activities is delayed in this frequently elderly population. Recently, short-term outcome studies have reported that minimally invasive approaches to PEH may be associated with a lower complication rate, a shorter hospital stay, and faster recovery.

METHODS

From July 1995 to February 2000, 100 patients (median age 68) underwent laparoscopic repair of a giant PEH. Follow-up included heartburn scores and quality of life measurements using the SF-12 physical component and mental component summary scores.

RESULTS

There were 8 type II hernias, 85 type III, and 7 type IV. Sac removal, crural repair, and antireflux procedures were performed (72 Nissen, 27 Collis-Nissen). The 30-day death rate was zero; there was one surgery-related death at 5 months from a perioperative stroke. Intraoperative complications included pneumothorax, esophageal perforation, and gastric perforation. There were three conversions to open surgery. Major postoperative complications included stroke, myocardial infarction, pulmonary emboli, adult respiratory distress syndrome, and repeat operations (two for abscess and one each for hematoma, repair leak, and recurrent hernia). Median length of stay was 2 days. Median follow-up at 12 months revealed resumption of proton pump inhibitors in 10 patients and one repeat operation for recurrence. The mean heartburn score was 2.3 (0, best; 45, worst); the satisfaction score was 91%; physical and mental component summary scores were 49 and 54, respectively (normal, 50).

CONCLUSION

This report represents the largest series to date of laparoscopic repair of giant PEH. In the authors' center with extensive experience in minimally invasive surgery, laparoscopic repair of giant PEH was successfully performed in 97% of patients, with a minimal complication rate, a 2-day length of stay, and good intermediate results.

Minimally invasive esophagectomy

BACKGROUND

Open esophagectomy can be associated with significant morbidity and delay return to routine activities. Minimally invasive surgery may lower the morbidity of esophagectomy but only a few small series have been published.

METHODS

From August 1996 to September 1999, 77 patients underwent minimally invasive esophagectomy. Initially, esophagectomy was approached totally laparoscopically or with mini-thoracotomy; thoracoscopy subsequently replaced thoracotomy.

RESULTS

Indications included esophageal carcinoma (n = 54), Barrett's high-grade dysplasia or carcinoma in situ (n = 17), and benign miscellaneous (n = 6). There were 50 men and 27 women with an average age of 66 years (range 30 to 94 years). Median operative time was 7.5 hours (4.5 hours with > 20 case experience). Median intensive care unit stay was 1 day (range 0 to 60 days); median length of stay was 7 days (range 4 to 73 days) with no operative or hospital mortalities. There were four nonemergent conversions to open esophagectomy; major and minor complication rates were 27% and 55%, respectively.

CONCLUSIONS

Minimally invasive esophagectomy is technically feasible and safe in our center, which has extensive minimally invasive and open esophageal experience. Open surgery should remain the standard until future studies conclusively demonstrate advantages of minimally invasive approaches.

Total Videothoracoscopic Lobectomy Versus Open Thoracotomy for Early-Stage Non–Small-Cell Lung Cancer

Lobectomy remains the standard procedure for early-stage non small-cell lung cancer (NSCLC). Advances in minimally invasive surgery allow lobectomy to be performed by videothoracoscopy (VATSLOBE). The objective of this study was to compare open thoracotomy (OPENLOBE) to VATSLOBE in the treatment of early-stage NSCLC. A retrospective review over a 6-year period at a single tertiary care center identified 31 patients treated by VATSLOBE. A comparison was made with 31 patients undergoing OPENLOBE during the same time period. The cases were matched for age, pulmonary function testing, tumor size, and comorbidities. The VATSLOBE technique was carried out using four 1 cm thoracoports, one of which was enlarged to a 4-6 cm access incision for lobe retrieval. OPENLOBE was performed by standard posterolateral thoracotomy. The VATSLOBE group had a longer operative time (214.03 min) compared to OPENLOBE (140.67 min). There was no difference in the extent of lymph node dissection or in morbidity between the two groups. VATSLOBE patients had their chest tubes removed earlier (4.77 vs. 8.16 days) and stayed in the hospital for a shorter time (7.07 vs. 11.94 days) compared to OPENLOBE patients. In this retrospective review, lobectomy performed by the videothoracoscopic approach was comparable to OPENLOBE in terms of lymph node dissection, morbidity, and long-term survival. VATSLOBE had the advantages of a shorter hospital stay and fewer days with a chest tube. Minimally invasive surgery for early-stage lung cancer should be further investigated in multi-institutional controlled trials.

Minimally invasive surgical staging for esophageal cancer

BACKGROUND

The incidence of esophageal adenocarcinoma is increasing in the United States, and the 5-year survival rate is dismal. Preliminary data suggest that conventional imaging is inaccurate in staging esophageal cancer and could limit accurate assessment of new treatments. The objective of this study was to compare minimally invasive surgical staging (MIS) with conventional imaging for staging esophageal cancer.

METHODS

Patients with potentially resectable esophageal cancer were eligible. Staging by conventional methods used computed tomography (CT) scan of the chest and abdomen, and endoscopic ultrasound (EUS), whereas MIS used laparoscopy and videothoracoscopy. Conventional staging results were compared to those from MIS.

RESULTS

In 53 patients, the following stages were assigned by CT scan and EUS: carcinoma in situ (CIS; n = 1), I (n = 1), II (n = 23), III (n = 20), IV (n = 8). In 17 patients (32.1%), MIS demonstrated inaccuracies in the conventional imaging, reassigning a lower stage in 10 patients and a more advanced stage in 7 patients.

CONCLUSIONS

In 32.1% of patients with esophageal cancer, MIS changed the stage originally assigned by CT scan and EUS. Therefore, MIS should be applied to evaluate the accuracy of new noninvasive imaging methods and to assess new therapies for esophageal cancer.

Endoscopic photodynamic therapy for obstructing esophageal cancer: 77 cases over a 2-year period

BACKGROUND

Photodynamic therapy (PDT) is an alternative treatment option for the palliation of obstructive esophageal cancer. We report our experience with PDT for patients presenting with inoperable, obstructing, or bleeding esophageal cancer.

METHODS

Seventy-seven patients with inoperable, obstructing esophageal cancer were treated with PDT from November 1996 to July 1998. Photofrin (1.5-2.0 mg/kg) was administered, followed by endoscopic light treatment (630 nm red dye laser) at 48 h. Dysphagia score (1 for no dysphagia to 5 for complete obstruction), dysphagia-free interval, and patient survival were assessed.

RESULTS

Seventy-seven patients underwent 125 PDT courses. The mean dysphagia score at 4 weeks after PDT in 90.8% of the patients improved from 3.2 +/- 0.7 to 1.9 +/- 0.8 (p < 0.05). PDT adequately controlled bleeding in all six patients who had bleeding. The most common complications after the 125 PDT courses were esophageal stricture (4.8%), Candida esophagitis (3.2%), symptomatic pleural effusion (3.2%), and sunburn (10.0%). Twenty-nine patients (38%) required more than one PDT course, and seven patients required placement of an expandable metal stent for recurrent dysphagia. The mean dysphagia-free interval was 80.3 +/- 58.2 days. The median survival was 5.9 months.

CONCLUSIONS

Photodynamic therapy is a safe and effective treatment for the palliation of obstructing and bleeding esophagus cancer.

Laparoscopic repair of giant paraesophageal hernia

Giant paraesophageal hernias (PEHs) account for less than 5% of all hiatal hernias. In contrast to the small type I hiatal hernia, nonsurgical management of giant PEHs may be associated with progression of symptoms and life-threatening complications including hemorrhage, strangulation, and death. Most giant PEHs are associated with a current or previous history of gastroesophageal reflux disease and represent progression of the typical type I hernia to a type III hernia. Conventional open repair is associated with good results and low mortality but also with a significant morbidity and a delay in return to routine activities in this frequently elderly population. Recently, short-term outcome studies have reported that minimally invasive approaches to PEH may be associated with less morbidity, shorter hospital stay, faster recovery, and excellent clinical results.

Airway complications following pediatric lung and heart-lung transplantation

Obstruction at the airway anastomosis is a recognized complication of adult heart-lung transplantation (HLT) and lung transplantation (LT). Data for pediatric transplantation have been scarce. We reviewed our experience in pediatric HLT and LT to determine the frequency of airway complications and to document the therapeutic modalities used for their treatment. Fifty-three patients (median age: 13.8 yr; range: 1.3 to 28.2 yr) underwent HLT (n = 25), SLT (n = 3), DLT (n = 25), or repeat DLT (n = 3) and survived for more than 72 h. Major anastomotic airway complications requiring intervention affected one of the 25 HLT (4%) and seven of the 28 LT (SLT + DLT) patients (25%) (p = 0.05). Four patients with granulation tissue occluding the airway were treated with forceps resection, laser ablation, or balloon dilatation. Three patients with fibrotic strictures received silicone stents, laser ablation, or balloon dilatation. Two patients with bronchomalacia or diffuse stricture below the anastomosis underwent metal stent placement. Five of seven patients who were treated for anastomotic complications had satisfactory relief of airway obstruction. As compared with previously studied adults, pediatric heart-lung transplant recipients had the same or a lower frequency, and pediatric lung transplant recipients had a higher frequency of major anastomotic airway complications. A variety of treatment modalities were necessary to achieve adequate relief of airway obstruction.

Risk analysis for thoracoscopic lung volume reduction: a multi-institutional experience

OBJECTIVE

Most reports of thoracoscopic lung volume reduction (TLVR) are relatively small and early experiences from a single institution, factors which limit both the statistical validity and the applicability to the population at large. In order to address these shortcomings we undertook an analysis of the TLVR experience at five separate institutions to assess operative morbidity and identify predictors of mortality.

METHODS

Questionnaires were sent to four groups of surgical investigators at five institutions actively performing TLVR. Data was requested regarding preoperative, operative and postoperative parameters. Twenty-five potential predictors of mortality were analyzed and seven proved to be at least marginally significant (P<0.10). These parameters were entered into a stepwise logistic regression analysis to identify independent predictors.

RESULTS

The 682 patients (415 males, 267 females, mean age 64.0 years) underwent unilateral (410) or bilateral (272) TLVRs. Overall, operative mortality was 6% with half of the deaths resulting from respiratory causes. The remaining patients were discharged to home (88%), a rehabilitation facility (4%) or a ventilator facility (2%). There were 25 perioperative factors chosen representing clinically important indices such as spirometry, oxygenation, functional status, clinical and demographic variables. Univariate analysis identified seven variables as predictors of mortality (P<0.10) and these were entered into a stepwise logistic regression analysis. Only age, 6-min walk, gender (male 8%, female 3% mortality) and the procedure performed (unilateral 4.6%, bilateral 8%) were independent predictors while preoperative steroid therapy, preoperative oxygen administration, and time since smoking cessation dropped out of the model. The specific institution, learning curve (early vs. late experience), type of lung disease, spirometric indices and predicted maximum VO(2) were not significant predictors.

CONCLUSION

This experience suggests that unilateral and bilateral lung volume reduction procedure can be performed with acceptable morbidity and mortality. Although age, gender, exercise capacity and the procedure performed are all independent predictors of mortality, the risk of operative death did not appear excessive in this fragile patient subset.

Comparison of clinical results for unilateral and bilateral thoracoscopic lung volume reduction

BACKGROUND

It is widely believed that bilateral thoracoscopic lung volume reduction (BTLVR) yields superior results when compared with unilateral thoracoscopic lung volume reduction (UTLVR) with regard to spirometry, functional capacity, oxygenation and quality of life results.

METHODS

To address these issues, we compared the results of patients undergoing UTLVR (N = 338 patients) and BTLVR (N = 344 patients) from 1993 to 1998 at five institutions. Follow-up data were available on 671 patients (98.4%) between 6 and 12 months after surgery, and a patient self-assessment was obtained at a mean of 24 months.

RESULTS

It was found that BTLVR provides superior improvement in measured postoperative percent change in FEV1 (L) (UTLVR 23.3% +/- 55.3 vs BTLVR 33% +/- 41, p = 0.04), FVC(L) (10.5% +/- 31.6 vs 20.3% +/- 34.3, p = 0.002) and RV(L) (-13% +/- -22 vs -22% +/- 17.9, p = 0.015). BTLVR also provides a slight improvement over UTLVR in patient's perception regarding improved quality of life (UTLVR 79% vs BTLVR 88%, p = 0.03) and dyspnea relief (71% vs 61%, p = 0.03). There was no difference in mean changes in PO2 (mm Hg) (UTLV 4.5 +/- 12.3 vs BTLVR 4.9 +/- 13.3, p = NS), 6-minute walk (UTLVR 26% +/- 66.1 vs BTLVR 31% +/- 59.6, p = NS) or decreased oxygen utilization (UTLVR 78% vs BTLVR 74%, p = NS).

CONCLUSIONS

These data suggest that both UTLVR and BTLVR yield significant improvement, but the results of BTLVR seem to be superior with regard to spirometry, lung volumes, and quality of life.

Effects of donor bone marrow infusion in clinical lung transplantation

BACKGROUND

We have demonstrated that donor cell chimerism is associated with a lower incidence of obliterative bronchiolitis (OB) in lung recipients, and that donor chimerism is augmented by the infusion of donor bone marrow (BM). We herein report the intermediate results of a trial combining the infusion of donor BM and lung transplantation.

METHODS

Clinical and in vitro data of 26 lung recipients receiving concurrent infusion of donor bone marrow (3.0 to 6.0 x 10(8) cells/kg) were compared with those of 13 patients receiving lung transplant alone.

RESULTS

Patient survival and freedom from acute rejection were similar between groups. Of the patients whose graft survived greater than 4 months, 5% (1 of 22) of BM and 33% (4 of 12) of control patients, developed histologic evidence of OB (p = 0.04). A higher proportion (but not statistically significant) of BM recipients (7 of 10, 70%) exhibited donor-specific hyporeactivity by mixed lymphocyte reaction assays as compared with the controls (2 of 7, 28%).

CONCLUSIONS

Infusion of donor BM at the time of lung transplantation is safe, and is associated with recipients' immune modulation and a lower rate of obliterative bronchiolitis.

Balloon dilation and endobronchial stent placement for bronchial strictures after lung transplantation

PURPOSE

To evaluate the effect of balloon dilation and endobronchial stent placement for bronchial fibrous stenoses and bronchomalacia after lung transplantation.

MATERIALS AND METHODS

Bronchial dilation and/or stent placement was performed on 25 lung transplant recipients. Indications included severe dyspnea with postobstructive pneumonia (n = 24) and respiratory failure (n = 1). All patients underwent pulmonary function testing (PFT) before and after bronchial dilation, the results of which were evaluated for changes. A total of 63 procedures were performed between February 1996 and December 1998. Thirty-five lesions were treated (18 were due to bronchomalacia, 17 were due to fibrosis). Areas treated included the left mainstem bronchus (n = 11), bronchus intermedius (n = 10), right mainstem bronchus (n = 7), left upper lobe bronchus (n = 4), right lower lobe bronchus (n = 2), and right middle lobe bronchus (n = 1). Bronchoscopic and/or bronchographic follow-up ranged from 1 to 34 months (mean, 15 months).

RESULTS

Six-month primary patency of stents placed for bronchomalacia was 71% (10 of 14), with three of the four occlusions caused by mechanical failure of Palmaz stents in the mainstem bronchi. Six-month primary patency for treatment of fibrous strictures was 29%. Secondary patency at 1 year was 100% for both bronchomalacia and fibrous strictures. After treatment, there was a significant improvement in mean PFT results (P = .01-.0001). There was one acute complication, obstruction of the left lower lobe bronchus by a Wallstent treated by dilating a hole in the side of the stent.

CONCLUSIONS

Balloon dilation and stent placement are safe and effective for bronchial strictures and bronchomalacia after lung transplantation, resulting in significant improvement in PFT results. However, there is almost universal restenosis in patients treated for fibrous strictures necessitating reintervention for prolonged patency.

Long-term survival after thoracoscopic lung volume reduction: a multiinstitutional review

BACKGROUND

It has been suggested that bilateral thoracoscopic lung volume reduction (BTLVR) yields significantly better long-term survival than unilateral thoracoscopic lung volume reduction (UTLVR).

METHODS

All perioperative data were collected at the time of the procedure. Follow-up data were obtained during office visits or by telephone.

RESULTS

A total of 673 patients underwent thoracoscopic LVR: 343 had either simultaneous or staged BTLVR and 330, UTLVR. As of July 1998, follow-up was available on 667 (99%) of the 673 patients with a mean follow-up of 24.3 months. The patients in the BTLVR group were significantly younger (62.6+/-8.0 years versus 65.4+/-8.1 years; p < 0.0001), had a higher preoperative arterial oxygen tension (69.7+/-12 mm Hg versus 65.3+/-11 mm Hg; p < 0.0001), and had a superior preoperative 6-minute walk performance (279.9+/-93.6 m [933+/-312 feet] versus 244.5+/-101.4 m [815+/-338 feet] p < 0.0001). There was no difference in the operative mortality rate between the two groups (UTLVR, 5.1%, and BTLVR, 7%). Actuarial survival rates for the UTLVR group at 1 year, 2 years, and 3 years were 86%, 75%, and 69%, respectively versus 90%, 81%, and 74%, respectively, for the BTLVR group (p = not significant).

CONCLUSIONS

Contrary to previous reports, survival after BTLVR was not superior to that after UTLVR even though the former group appeared to have a lower risk preoperatively because of younger age, higher arterial oxygen tension, more advantageous anatomy, and better functional status. Despite thoracoscopic LVR, the actuarial mortality rate approached 30% at 3 years, and this calls into question whether this procedure offers any survival advantage to patients with end-stage emphysema.

Effect of ischemic time on survival in clinical lung transplantation

BACKGROUND

While there is convincing evidence that prolonged ischemic times correlate with reduced long-term survival in heart transplantation, the effect of ischemic time on outcome in clinical lung transplantation remains controversial. To assess the effect of ischemic time on outcomes in lung transplantation, we reviewed our experience.

METHODS

The study was performed by retrospective chart review.

RESULTS

First-time lung transplantation was performed on 392 patients between 1988 and 1998. All grafts were flushed with cold crystalloid preservation solution and stored on ice. Ischemic time data were available for 352 of 392 (90%) patients. Ischemic times were grouped as follows: 0 to 4 hours (n = 91), 4 to 6 hours (n = 201), more than 6 hours (n = 60). Ischemic time did not correlate with survival: 3-year actuarial survival = 56% (0 to 4 hours), 58% (4 to 6 hours), 68% (> 6 hours), p = 0.58. There was no significant difference in the incidence of biopsy-proven diffuse alveolar damage in the first 30 days after transplantation (31%, 32%, 38%), episodes of acute rejection in the first 100 days after transplantation (1.9, 1.8, 1.7), duration of intubation (median 3, 4, 3 days), or incidence of obliterative bronchiolitis (23%, 28%, 26%) between the three groups (0 to 4 hours, 4 to 6 hours, > 6 hours, respectively). A diagnosis of diffuse alveolar damage was associated with a significantly worse outcome (1-year survival = 82% versus 54%, p < 0.0001).

CONCLUSIONS

In contrast to heart transplantation, pulmonary allograft ischemic time up to 9 hours does not appear to have a significant impact on early graft function or survival. The presence of diffuse alveolar damage on biopsy early after transplantation does not correlate with prolonged ischemic time, but is associated with substantially reduced posttransplantation survival.

Optimism and coping styles: A comparison of candidates for liver transplantation with candidates for lung transplantation

BACKGROUND

Dispositional optimism and adaptive coping styles have been shown to correlate with each other and with physical and psychological well-being in a number of studies with medical patients. Few studies in the transplant literature evaluate psychological characteristics of patients across medical diagnoses. A comparison of optimism and coping styles among candidates for liver and lung transplantation is presented.

METHOD

Subjects were 73 candidates for lung transplantation at the University of Pittsburgh Medical Center and 76 candidates for liver transplantation at the Pittsburgh VA Healthcare System. All candidates were classified according to medical diagnosis and history of substance abuse (alcohol/drugs or smoking). There were no significant between- or within-group differences on optimism.

RESULTS

There was a significant difference within both groups, according to history of substance abuse on the coping style 'acceptance'. There were also significant between-group differences on a number of coping styles.

CONCLUSIONS

This preliminary study is intended to suggest direction for future research; studying psychological variables known to impact on health apart from medical diagnosis may provide data pertinent to selection criteria and the design of interventions to more effectively maximize the benefit of transplantation for all concerned.

Structure of the phylogenetically most conserved domain of SRP RNA

The signal recognition particle (SRP) is a phylogenetically conserved ribonucleoprotein required for cotranslational targeting of proteins to the membrane of the endoplasmic reticulum of the bacterial plasma membrane. Domain IV of SRP RNA consists of a short stem-loop structure with two internal loops that contain the most conserved nucleotides of the molecule. All known essential interactions of SRP occur in that moiety containing domain IV. The solution structure of a 43-nt RNA comprising the complete Escherichia coli domain IV was determined by multidimensional NMR and restrained molecular dynamics refinement. Our data confirm the previously determined rigid structure of a smaller subfragment containing the most conserved, symmetric internal loop A (Schmitz et al., Nat Struct Biol, 1999, 6:634-638), where all conserved nucleotides are involved in nucleotide-specific structural interactions. Asymmetric internal loop B provides a hinge in the RNA molecule; it is partially flexible, yet also uniquely structured. The longer strand of internal loop B extends the major groove by creating a ledge-like arrangement; for loop B however, there is no obvious structural role for the conserved nucleotides. The structure of domain IV suggests that loop A is the initial site for the RNA/protein interaction creating specificity, whereas loop B provides a secondary interaction site.

Psychological symptom levels and their correlates in lung and heart-lung transplant recipients

This study examined depression, anxiety, and anger-hostility symptom levels, as well as overall quality of life, in a cohort of 50 lung and heart-lung transplant recipients. Only the subjects' mean anxiety symptoms were substantially elevated over normative levels. However, nearly half of the sample showed clinically significant distress in one or more of the three symptom areas. Pretransplant psychiatric history, educational level, posttransplant caregiver support, and health concerns were the most important independent correlates of the recipients' psychological outcome. Low sense of mastery and poorer physical functional status also showed some evidence of association with mental health.

Diagnostic and therapeutic video-assisted thoracic surgery resection of pulmonary metastases

BACKGROUND

Appropriateness of video-assisted thoracic surgery (VATS) pulmonary metastasectomy for curative intent has been a controversial topic. We reviewed our experience with VATS wedge resection for peripheral lung metastases to determine the efficacy and potential adverse consequences of this approach for pulmonary metastasectomy.

METHODS

One hundred seventy-seven patients underwent VATS resection of pulmonary metastases. Diagnostic resection (VATS-dx) was performed for 78 patients when percutaneous biopsy was unsuccessful or not feasible. Potentially curative resections (VATS-rx) were performed for 99 patients. The histologic findings in this group included colorectal (68), renal (7), sarcoma (6), breast (4), melanoma (3), head/neck (3), lymphoma (2), uterine (1), and "other" (5). The average number of lesions resected was 1.4 (range, 1-7).

RESULTS

VATS resection was successfully performed for all VATS-dx and VATS-rx patients. There were no perioperative deaths. Longitudinal follow-up demonstrated a mean survival of 18 months in the VATS-dx group and 28 months in the VATS-rx group. In the VATS-rx group, 37 (37%) of 99 were free of disease, at a mean follow-up interval of 37 months. Of the 57 recurrences, 5% were local, 26% were regional, and 69% were distant.

CONCLUSIONS

Results with VATS resection of peripheral pulmonary metastases for diagnostic and potentially curative intentions appear comparable with historical results by "open" thoracotomy. Careful patient selection based on high-resolution helical CT scanning is important to avoid compromise of therapeutic intent. Conversion to thoracotomy is indicated when lesions identified preoperatively are not found or when technical problems encountered may compromise surgical margins when resecting lung metastases for potential cure.

Evaluation of distant metastases in esophageal cancer: 100 consecutive positron emission tomography scans

BACKGROUND

Pilot studies suggest positron emission tomography (PET) scanning may be superior to conventional imaging in staging esophageal cancer, especially in the detection of radiographically occult distant metastases. This report summarizes our experience with PET in staging esophageal cancer.

METHODS

One hundred consecutive PET scans in 91 patients with esophageal cancer referred for surgery were prospectively collected (1995 to 1998) and compared with computerized tomography (CT) and bone scan. PET images were acquired after injection of 18F-fluorodeoxyglucose and evaluated for abnormal uptake. Minimally invasive surgical staging (MIS) and/or clinical correlation were used to confirm or refute imaging results.

RESULTS

MIS or clinical correlation confirmed 70 distant metastases in 39 cases. PET detected 51 metastases in 27 of 39 cases (69% sensitivity, 93.4% specificity, 84% accuracy) compared with CT, which detected 26 metastases in 18 of 39 cases (46.1% sensitivity, 73.8% specificity, 63% accuracy) (p < 0.01).

CONCLUSIONS

PET was more accurate than CT in detecting distant metastases, but was only 69% sensitive compared with minimally invasive staging.

Diagnostic and therapeutic video-assisted thoracic surgery resection of pulmonary metastases

BACKGROUND

Appropriateness of video-assisted thoracic surgery (VATS) pulmonary metastasectomy for curative intent has been a controversial topic. We reviewed our experience with VATS wedge resection for peripheral lung metastases to determine the efficacy and potential adverse consequences of this approach for pulmonary metastasectomy.

METHODS

One hundred seventy-seven patients underwent VATS resection of pulmonary metastases. Diagnostic resection (VATS-dx) was performed for 78 patients when percutaneous biopsy was unsuccessful or not feasible. Potentially curative resections (VATS-rx) were performed for 99 patients. The histologic findings in this group included colorectal (68), renal (7), sarcoma (6), breast (4), melanoma (3), head/neck (3), lymphoma (2), uterine (1), and "other" (5). The average number of lesions resected was 1.4 (range, 1-7).

RESULTS

VATS resection was successfully performed for all VATS-dx and VATS-rx patients. There were no perioperative deaths. Longitudinal follow-up demonstrated a mean survival of 18 months in the VATS-dx group and 28 months in the VATS-rx group. In the VATS-rx group, 37 (37%) of 99 were free of disease, at a mean follow-up interval of 37 months. Of the 57 recurrences, 5% were local, 26% were regional, and 69% were distant.

CONCLUSIONS

Results with VATS resection of peripheral pulmonary metastases for diagnostic and potentially curative intentions appear comparable with historical results by "open" thoracotomy. Careful patient selection based on high-resolution helical CT scanning is important to avoid compromise of therapeutic intent. Conversion to thoracotomy is indicated when lesions identified preoperatively are not found or when technical problems encountered may compromise surgical margins when resecting lung metastases for potential cure.

Functional changes in the structure of the SRP GTPase on binding GDP and Mg2+GDP

Ffh is a component of a bacterial ribonucleoprotein complex homologous to the signal recognition particle (SRP) of eukaryotes. It comprises three domains that mediate both binding to the hydrophobic signal sequence of the nascent polypeptide and the GTP-dependent interaction of Ffh with a structurally homologous GTPase of the SRP receptor. The X-ray structures of the two-domain 'NG' GTPase of Ffh in complex with Mg2+GDP and GDP have been determined at 2.0 A resolution. The structures explain the low nucleotide affinity of Ffh and locate two regions of structural mobility at opposite sides of the nucleotide-binding site. One of these regions includes highly conserved sequence motifs that presumably contribute to the structural trigger signaling the GTP-bound state. The other includes the highly conserved interface between the N and G domains, and supports the hypothesis that the N domain regulates or signals the nucleotide occupancy of the G domain.

Photodynamic therapy for treatment of malignant dysphagia

Photodynamic therapy (PDT) was recently approved by the Food and Drug Administration for palliating obstructing esophageal cancer. This report reviews our initial experience using PDT to treat malignant dysphagia. Patients with inoperable, obstructing esophageal cancer were considered for PDT. Photofrin was injected 48 hours before endoscopic laser activation. Dysphagia score was assessed. Thirty patients underwent 53 PDT courses. Improvement in dysphagia occurred in 83%. Mean dysphagia score decreased from 2.8 to 1.8 (p < 0.05). Complications included esophageal stricture (9.4%), candida esophagitis (5.7%), symptomatic pleural effusion (5.7%), contained esophageal perforation (1.9%), aspiration pneumonia (1.9%), and sunburn (13.2%). Seventeen patients (57%) required more than one PDT treatment, and in 10 an expandable metal stent was used as an adjunct. The 30-day mortality rate was 7%. PDT is effective in palliating patients with malignant dysphagia. The ideal patient for PDT has an obstructing, primarily endoluminal esophageal tumor with minimal extrinsic compression.

Empyema complicating successful lung transplantation

OBJECTIVE

To assess the prevalence and etiology of empyema complicating successful lung transplantation.

DESIGN

Retrospective review.

SETTING

University medical center transplant service.

PATIENTS

All recipients (n = 392) of single-lung, double-lung, and heart-lung transplantation between May 1984 and April 1997.

RESULTS

Of the 392 transplant recipients, empyema was documented in 14 patients (3.6%) at a mean time (+/- SD) of 46 days after transplantation (range, 14 to 167 days). Of these 14 recipients with empyema, 4 recipients (28.6%) died of infectious complications related to empyema. Empyema was seen secondary to Gram-positive, Gram-negative, and saprophytic organisms; however, there was no predominance of a particular organism recovered from the empyemic fluid (chi2 = 0.53; p = 0.75). The development of empyema was not related to whether the transplant was performed secondary to a septic or nonseptic lung disorder (chi2 = 1.06; p = 0.67), nor was it related to the type of transplant procedure performed (ie, single-lung, double-lung, or heart-lung allografts; chi2 = 4.39; p = 0.30).

CONCLUSION

Empyema, a relatively uncommon complication of lung transplantation, is not related to the type of allograft received or to whether the recipient had a septic or a nonseptic lung disorder. If empyema does occur, the mortality associated with this infection is substantial.

Computed tomography-guided wire localization of pulmonary lesions before thoracoscopic resection: results in 101 cases

The authors determine the success rate, safety, and potential complications of computed tomography-guided preoperative hookwire localization of small peripheral pulmonary nodules. One hundred one consecutive wire localizations with addition of methylene blue injection were performed in 94 patients immediately before thoracoscopic resection of small lung lesions. Sixty-two patients had a known primary malignancy, whereas 32 had an asymptomatic nodule. Eighty-eight patients underwent single lesion localization, five underwent double localization, and one underwent triple wire placement. Five patients had previously undergone percutaneous biopsy that was nondiagnostic. The nodule was within the first wedge biopsy of lung tissue in 95 of 97 specimens (98%). A second wedge and an open lobectomy were required in one patient each. Three additional biopsies were intraoperatively deferred after the histologic diagnosis was established after removal of another nodule. The procedure was terminated before wire placement in one patient who was unable to successfully hold his breath. The wire dislodged with the tip in the pleural space rather than in the lung parenchyma in 22 cases; however, methylene blue tattoo allowed localization in 13 of these (59%). In the other nine cases, extra portals, digital palpation, or expanded wedge resection was required. Complications included pneumothorax in 48 cases, moderate pleuritic pain in five cases, seven small intercostal hematomas, and a 7-mm wire fragment retained in one patient's lung along the suture line. No patient required a preoperative drain for treatment of pneumothorax. Wire dislodgement occurred in 6 of 52 (12%) cases without an initial pneumothorax and in 16 of 48 (33%) cases if a pneumothorax occurred. Wires dislodged less frequently if placed either directly into or through the nodule in 11 of 64 (17%) cases than if placed adjacent to the nodule in 11 of 36 (31%) cases. Average wire tip depth from the visceral pleura was significantly less when the wire dislodged (11 mm) than when the wire remained in place (25 mm). Wire localization of small peripheral pulmonary nodules is a safe and effective procedure to assist thoracoscopic sublobectomy resection.