[Reduced quality of life in patients with unilateral vocal cord paralysis after thoracic surgery]. / Beeinträchtigung der Lebensqualität bei Patienten mit einseitiger Rekurrensparese nach thoraxchirurgischen Eingriffen.

BACKGROUND: Postoperative unilateral vocal cord paralysis (URLNP) may lead to a lower quality of life due to dysphonia, dysphagia, and reduced breathing control. The aim of this study was to evaluate quality of life in a group of patients with URLNP compared to a group without URLNP. PATIENTS AND METHODS: Laryngoscopically, 379 patients were examined before and after thoracic surgery. Of the group with permanent URLNP (n=14), nine patients were compared to ten without URLNP regarding voice function and quality of life using selected European Organization for Research and Treatment of Cancer questionnaires (QLQ-C30, H&N35, OES18, and LC13) and the voice dysfunction index by Nawka. RESULTS: Patients with URLNP reported more voice problems and less effective coughing. Further, they had a reduced of quality of life. CONCLUSION: We recommend early diagnosis of URLNP and therapy management by routine laryngoscopic examinations following thoracic surgery.

Limited bifurcation asymmetry in coronary arterial tree models generated by constrained constructive optimization.

Models of coronary arterial trees are generated by the algorithm of constrained constructive optimization (CCO). In a given perfusion area a binary branching network of straight cylindrical tubes is generated by successively adding terminal segments to the growing structure. In each step the site of connection is chosen according to an optimization target function (total intravascular volume), and in any stage of development the tree fulfills physiologic boundary conditions (constraints involving pressures, flows and bifurcation rules). CCO generates structures which in many aspects resemble real coronary arterial trees, except for very asymmetric bifurcations, occurring when a large branch gives off a tiny terminal segment. In the present work we evaluate an additional constraint within CCO, namely imposing a limit on the asymmetry of bifurcations during the construction process. Model trees are grown with different limits imposed, and the effects on structure are studied both phenomenologically and via statistical descriptors. As the limit to asymmetry is tightened, blood is conveyed to the perfusion sites via detours rather than directly and the comparison with measured data shows that the structure to change from a conveying to a delivering type of function. Simultaneously total intravascular volume, surface and sum of segments' lengths increase. It is shown why and how local bifurcation asymmetry is able to determine the global structure of the optimized arterial tree model. Surprisingly, the pressure profile from inlet to terminals, being a functional characteristic, remains unaffected.

The influence of optimization target selection on the structure of arterial tree models generated by constrained constructive optimization.

The computational method of constrained constructive optimization was used to generate complex arterial model trees by optimization with respect to a target function. Changing the target function also changes the tree structure obtained. For a parameterized family of target functions a series of trees was created, showing visually striking differences in structure that can also be quantified by appropriately chosen numerical indexes. Blood transport path length, pressure profile, and an index for relative segment orientation show clear dependencies on the optimization target, and the nature of changes can be explained on theoretical grounds. The main goal was to display, quantify, and explain the structural changes induced by different optimization target functions.

The branching angles in computer-generated optimized models of arterial trees.

The structure of a complex arterial tree model is generated on the computer using the newly developed method of "constrained constructive optimization." The model tree is grown step by step, at each stage of development fulfilling invariant boundary conditions for pressures and flows. The development of structure is governed by adopting minimum volume inside the vessels as target function. The resulting model tree is analyzed regarding the relations between branching angles and segment radii. Results show good agreement with morphometric measurements on corrosion casts of human coronary arteries reported in the literature.

Anemia and erythropoietin levels in lung transplant recipients.

An evaluation of 26 surviving outpatient lung transplant recipients at one center showed that 65% (17/26) had significant anemia (hemoglobin < 11 g/L for women, < 14 g/dl for men) at a median follow-up of 13.5 months after transplantation (range, 1-41 months). There were 14 men and 12 women with a mean age of 45.1 years (range, 23.1-66.7 years). Fifteen had a double allograft and 11 had a single allograft. Anemia was normochromic and normocytic/macrocytic with a tendency to anisocytosis, with normal reticulocyte counts. Iron deficiency (transferrin saturation < 20%) was found in 35% (6/17) of anemic patients, and two of them also had ferritin levels < 15 micrograms/L. In addition, vitamin B12 was decreased in 1 patient. Folate levels were all normal. Erythropoietin levels were significantly decreased in anemic lung transplant recipients as compared with nontransplanted iron-deficient anemic patients (median, 1 mU/ml, range 1-41 mU/ml, vs. 53 mU/ml, 15-88 mU/ml; P < 0.05). In nonanemic lung transplant recipients, erythropoietin levels were decreased too, as compared with normal controls (median, 2 mU/ml, range 1-21 mU/ml, vs. 5 mU/ml, 3-32 mU/ml; P < 0.05). Investigation of peripheral stem cells in 9 patients showed normal stimulation of erythroids (burst-forming unit, erythroid; median, 573 cells/ml; range, 128-1898 cells/ml) independent of erythropoietin concentrations. Analysis of putative prognostic factors, such as age, surgical procedure (double vs. single lung allograft), indication for transplantation, time after transplantation, infection status, presence of bronchiolitis obliterans, immunosuppression (+/- azathioprine), serum creatinine, creatinine clearance, hypertension, and arterial partial pressure of oxygen, did not demonstrate any difference in erythropoietin concentrations. Only the sex variable revealed a trend to higher levels in women than in men (median, 4 mU/ml, range 1-41 mU/ml, vs. 1 mU/ml, 1-16 mU/ml; P > 0.05). The causes for low erythropoietin levels are not quite understood yet; however, they offer a rationale for the treatment of chronic anemia with recombinant human erythropoietin.

The pulmonary nodule after lung transplantation. Cause and outcome.

In the immunocompromised patient, the pulmonary nodule remains a diagnostic and therapeutic challenge. We studied the incidence, cause, diagnosis, and therapy of pulmonary nodules after lung transplantation (LTx). Eight out of 64 patients (12.5%) developed pulmonary nodules after a median follow-up of 5.8 months (range, 1 to 10 months). The median age was 30.5 years (range, 21 to 62 years). Solitary pulmonary nodules (n = 2) disappeared spontaneously within 3 weeks and were suspected to be of infectious origin. The cause of multiple nodules (n = 6) was posttransplant lymphoproliferative disorder (PTLD [n = 3]), aspergillosis (n = 2), and abscesses caused by Pseudomonas aeruginosa and Staphylococcus aureus (n = 1). After an initial chest radiograph, CT with fine-needle biopsy was the most valuable diagnostic tool. In six patients, nodules resolved within 10 weeks (median, 8 weeks). Two patients, however, died of sepsis (P aeruginosa and S aureus and Aspergillus, respectively). The differential diagnosis of pulmonary nodules after LTx primarily comprises PTLD and infection (bacterial or fungal). To improve the outcome, early, aggressive treatment is mandatory; therefore, serial CT scans are strongly recommended to be part of the diagnostic armamentarium in LTx recipients.

Early bacterial infections in lung transplant recipients.

Early bacterial pulmonary infections within 2 weeks after lung transplantation were studied in 29 patients undergoing surgery between December 1989 and May 1992. Suspected pulmonary infections occurred in 11 patients (38 percent). The most common bacterial organisms isolated were Klebsiella pneumoniae (45 percent; 5/11), Pseudomonas aeruginosa (36 percent; 4/11), Escherichia coli (27 percent; 3/11), Staphylococcus aureus (18 percent; 2/11), and Enterobacter cloacae (18 percent; 2/11). The mortality due to infection was 3 percent (1/29) in the early postoperative period. None of the following variables was found to be of prognostic significance: positive donor cultures, ischemic time of the graft, use of cardiopulmonary bypass, number of courses of methylprednisolone for acute rejection, duration of postoperative intubation, and type of surgical procedure. The presence of infection in the early postoperative period did not influence long-term survival. In the absence of prognostic parameters, prompt adjustment of antibiotic therapy to the results of antibiograms remains the most important therapeutic step in the management of infections in the early postoperative period after lung transplantation.

Aerobic endurance training program improves exercise performance in lung transplant recipients.

STUDY OBJECTIVE: To determine whether an aerobic endurance training program (AET) in comparison to normal daily activities improves exercise capacity in lung transplant recipients. PATIENTS AND STUDY DESIGN: Nine lung transplant recipients (12+/-6 months after transplant) were examined. All patients underwent incremental bicycle ergometry with the work rate increased in increments of 20 W every 3 min. Identical exercise tests were performed after 11+/-5 weeks of normal daily activities and then after a 6-week AET. The weekly aerobic training time increased from 60 min at the beginning to 120 min during the last week. Training intensity ranged from 30 to 60% of the maximum heart rate reserve. RESULTS: Normal daily activities had no effect on exercise performance. The AET induced a significant decrease in resting minute ventilation from 14+/-5 to 11+/-3 L/min. At an identical, submaximal level of exercise, a significant decrease in minute ventilation from 47+/-14 L/min to 39+/-13 L/min and heart rate from 144+/-12 to 133+/-17 beats/min, before and after the AET, was noted. The increase in peak oxygen uptake after AET was statistically significant (1.13+/-0.32 to 1.26+/-0.27 L/min). CONCLUSIONS: These data demonstrate that normal daily activities do not affect exercise performance in lung transplant recipients > or = 6 months after lung transplantation. An AET improves submaximal and peak exercise performance significantly.

Bronchoplastic procedures in malignant and nonmalignant disease: multivariable analysis of 144 cases.

OBJECTIVES: We sought to analyze the experience with bronchoplastic procedures over a 7-year period and to determine putative prognostic factors for survival. METHODS: From 1991 to 1997, 144 bronchoplastic procedures were performed for non-small cell lung cancer (n = 123), small cell lung cancer (n = 5), carcinoid tumor (n = 10), and metastases of extrathoracic malignant tumors (n = 6). There were 111 sleeve lobectomies, 17 bilobectomies, 4 lobectomies with carinal resection, 8 sleeve pneumonectomies, and 4 bronchotomies without parenchymal resection. Multivariable analysis included risk factors, such as age, sex, type of bronchoplastic procedure (bronchotomy, lobectomy, bilobectomy, or pneumonectomy), additional angioplasty, TNM staging, histology, radicality of resection, respiratory risk (forced expiratory volume in 1 second, percent predicted < 60), cardiovascular risk, and adjuvant therapy. RESULTS: Overall 1- and 3-year survival was 72% and 52%, respectively. The overall 30-day mortality was 8.3% (5.4% for single sleeve lobectomies). Multivariable analysis demonstrated 4 risk factors for survival. High tumor stage, type of bronchoplastic procedure, impaired lung function, and presence of cardiovascular risk were associated with a poor outcome. Univariate analysis showed reduced survival in patients with sleeve pneumonectomies (1-year survival, 25%). CONCLUSIONS: Bronchoplastic procedures for central tumors and sleeve pneumonectomies are associated with poor survival. Careful selection of these patients, as well as of patients with impaired lung function and cardiovascular risk factors, is mandatory.

Early experience with sequential bilateral lung transplantation.

We performed 20 sequential bilateral lung transplantation in 19 consecutive patients from April 1990 to May 1992. Perioperative mortality was low (2 patients). One-year actuarial survival was 70%. All survivors had normal blood oxygen tension (82 mm Hg, mean) while breathing room air and continuing improvement of pulmonary function. Bronchial dehiscence did not occur. Stents were implanted in 7 patients to control bronchial stenosis. Aggressive treatment of graft rejection has been effective in preventing obliterative bronchiolitis.

Molecular genetic differentiation between primary lung cancers and lung metastases of other tumors.

When solitary pulmonary tumors are observed in patients with a history of cancer, differentiation between metastasis and primary lung cancer is crucial for appropriate therapy. Assuming that p53 mutations are conserved in metastases, mutation analysis of the p53 gene would be a valuable tool in differentiating metastases from primary carcinomas of the lung. In nine of 267 resected lung tumors, the origin of the lung tumor could not be defined histologically. Five patients had a history of colorectal carcinoma, one had a history of breast carcinoma, one had a history of soft-tissue carcinoma, and one had a history of head and neck carcinoma. One patient with a clear cell carcinoma of the lung had been surgically treated for both renal and thyroid cancer. Material from one patient with adenocarcinoma of the lung, histologically defined regional lymph nodes, and distant brain metastasis served as a control. We extracted deoxyribonucleic acid from the snap-frozen tissue of the unclassified lung tumors, from paraffin-embedded tissue of the previously removed primary cancers, and also from peripheral blood of the patients. Exons 2 to 11 of the p53 gene were amplified in separated polymerase chain reactions and directly sequenced. In all cases, the presence of germline mutations was excluded by analysis of peripheral blood deoxyribonucleic acid. The p53 mutation detected in the deoxyribonucleic acid of the lung tumor of the control patient proved to be conserved in the lymph nodes as well as in the brain metastasis. In two cases, the lung tumors exhibited a p53 mutation not present in the previously removed primary tumor and were therefore classified as new primary lung cancers. In five cases, the lung tumors proved to be metastases of the first tumor, exhibiting the identical p53 mutation. One of these lung tumor samples could be identified as a metastasis from the renal cancer, but the corresponding thyroid cancer material was different. For two cases, molecular analysis remained inconclusive. In one case, no p53 mutation could be found in the compared samples; in the other, no deoxyribonucleic acid could be extracted. Analysis of p53 mutations allowed exact classification in tumors for which standard methods failed to distinguish between metastasis or primary tumor. More than two thirds of lung tumors in patients with previous gastrointestinal carcinoma were revealed to be metastases, but second primary lung cancer could also be diagnosed. This diagnosis allowed correct surgical and adjuvant treatment of these patients.

Successful lung transplantation in a long-term ventilator-dependent patient.

Ventilator dependence has been postulated to be a major contraindication for successful lung transplantation. We describe the case of a 44-year-old female patient mechanically ventilated for 10 months after adult respiratory distress syndrome. After a program of physical training the patient underwent successful bilateral sequential lung transplantation. Six months postoperatively she is in good physical condition and is able to carry out the activities of normal daily living. We conclude that in selected patients long-term mechanical ventilatory support is not a contraindication for lung transplantation.

Management of severe bronchial ischemia after bilateral sequential lung transplantation.

A case of severe diffuse bronchial ischemia after bilateral sequential lung transplantation is presented. A combination of initial conservative treatment with silicone stenting and late bilateral retransplantation under stable conditions resulted in good clinical outcome. Factors in decision making and technical aspects of the stenting procedure are discussed.

Long-term results after repeated surgical removal of pulmonary metastases.

BACKGROUND: Although surgical resection is accepted widely as first-line therapy for pulmonary metastases, few data exist on the surgical treatment of recurrent pulmonary metastatic disease. In a retrospective study, we analyzed patients who were operated on repeatedly for recurrent metastatic disease of the lung with curative intent over a 20-year period. METHODS: From 1973 to 1993, 396 metastasectomies were performed in 330 patients. The study population included patients with any histologic tumor type who had undergone at least two (range, 2 to 4) complete surgical procedures because of recurrent metastatic disease. Surgical and functional resectability of the recurrent lung metastases and control of the primary lesion served as objective criteria for reoperation. A subgroup of 35 patients that included patients with histologic findings such as epithelial cancer and osteosarcoma then was analyzed retrospectively to calculate prognosis and define selection criteria for repeated pulmonary metastasectomy. RESULTS: The 5- and 10-year survival rates after the first metastasectomy were 48% and 28%, respectively. The overall median survival was 60 months. A mean disease-free interval (calculated for all intervals, with a minimum of two) of greater than 1 year was significantly associated with a survival advantage beyond the last operation. Univariate analysis failed to show size, number, increase or decrease in number or size, or distribution of metastases as factors related significantly to survival. CONCLUSIONS: Although patients with different histologic tumor types were included, the study population appeared to be homogeneous in terms of survival benefit and prognostic factors, and it probably represented the selection of biologically favorable tumors in which histology, size, number, and laterality are of minor importance. We conclude that patients who are persistently free of disease at the primary location but who have recurrent, resectable metastatic disease of the lung are likely to benefit from operation a second, third, or even fourth time.

Five-year follow-up after heart valve replacement with the CarboMedics bileaflet prosthesis.

BACKGROUND: The CarboMedics valve is a relatively new, low-profile, bileaflet, mechanical prosthesis. The results of a prospective follow-up study after valve replacement with this prosthesis in a university hospital are presented. METHODS: We implanted 640 CarboMedics prostheses in 583 patients in the aortic (n = 359), mitral (n = 167), or aortic and mitral positions (double valve replacement; n = 57). Patient ages ranged from 11 to 81 years (mean age, 58 +/- 12.3 years). RESULTS: Overall hospital mortality was 9.0%; however, when high-risk urgent cases were removed from the calculation, the operative mortality fell to 4.5%. Follow-up was 98% complete, comprising 2,027 patient-years for a mean follow-up of 44 months (range, 6 to 72 months). Actuarial freedom from complications (linearized rates in parentheses) was as follows: late mortality, 85% +/- 2.0% (2.3%/patient-year); thromboembolism, 92% +/- 1.1% (1.6%/patient-year); anticoagulation-related hemorrhage, 87% +/- 1.2% (2.8%/patient-year); prosthetic valve endocarditis, 98% +/- 0.5% (0.1%/patient-year); and overall valve-related morbidity and mortality, 76% +/- 2.1% (4.3%/ patient-year). CONCLUSIONS: The CarboMedics valve shows a low rate of valve-related complications comparable with other new mechanical heart valve prostheses.

Survival after surgical treatment of recurrent pulmonary metastases.

OBJECTIVE: Resection of lung metastases is a generally accepted therapeutic strategy today. This retrospective study was performed in order to estimate the value of an aggressive surgical approach in recurrent metastatic disease of the lung. METHODS: The survival rates of 42 patients undergoing repeated resectional treatment for recurrent lung metastases (group A) were compared to the outcome of a total of 288 patients after a single surgical intervention for lung metastases (group B). Survival rates and the relative effects of the various prognostic factors were calculated according to Kaplan-Maier and Mantel Cox or Wilcoxon test. Histology of the primary tumors in group A consisted of 18 carcinomas, 22 sarcomas and two melanomas, in group B the distribution was 64% carcinoma, 27% sarcoma and 9% melanoma. The mean follow-up period was 88.5 months for group A and 27 months for group B. RESULTS: The overall survival rate for group A was 48% at 5 years and 30% at 10 years, the survival rate for group B was 34% at 5 years. CONCLUSION: Long-term survival rates superior to those after single resectional treatment for lung metastases encourage an aggressive surgical approach for this disease.

[The value of different clinical and imaging procedures for the postoperative follow-up of extra-anatomical bypasses]. / Wertigkeit unterschiedlicher klinischer und bildgebender Verfahren für die postoperative Verlaufskontrolle extraanatomischer Bypasses.

In order to judge the patency of extra-anatomical by-passes in the lower extremities, 24 patients with 29 by-passes were examined clinically (palpation of the by-pass pulse, Fontaine staging, Doppler index) and by imaging methods (i-v DSA, Duplex sonography, colour-coded Doppler sonography). The value of these methods was compared. Sonography was found to be the ideal method for follow-up. Palpation was unreliable, particularly for femoro-femoral by-passes. The Doppler index and the Fontaine method provided no information about the actual state of the bypass. Angiography is indicated only if further vascular reconstruction is planned.

Clinical and experimental results as a basis of surgical practice.

Since John Hunter first applied the scientific approach to surgery in the late 18th century, it has been raised from the humble level of a handicraft to a highly experimental science. Although surgical research is essential, the practice of surgery has always been much influenced by the basic sciences. The clinical significance of experimental data has often only been recognized years later: research to no pre-defined end is also of utmost importance. Today, in a time of cost explosion and overabundance of information, cooperative and statistically well-planned studies are essential to optimize financial and physical resources. Fields of increasing interest such as gene technology, immunology and preventive medicine will influence surgery in the near future. Minimal invasive and interventional techniques have already started to revolutionize surgical practice. So surgical research today combines traditional medicine and modern techniques to put into practice immediately. If surgeons consider their field to be a unity of "craftsmanship, art and science" [10] and at the same time adhere to the rules of ethics, they will comply with the principle of "saluti et solatio aegrorum".

[The extra-anatomic bypass in the therapy of aortoiliacal occlusive disease]. / Der extraanatomische Bypass in der Therapie der aortoiliakalen Verschlusskrankheit.

The extra-anatomic bypass procedure is a well accepted alternative to direct aortoiliac reconstruction in high-risk patients or in cases of local inoperability. Between 1980 and 1987 74 patients (54 men, 20 women; mean age = 71 years, 43 to 90) underwent a total of 78 extra-anatomic reconstructions: 23 axillounifemoral, 15 axillobifemoral, 34 femoro-femoral cross-over, 4 axillo-popliteal and 2 femoro-popliteal cross-over bypasses. The operations were performed for severe claudication in 16, rest pain in 27 and gangrene in 26 patients; acute ischaemia was the indication in 6 and acute aortic aneurysms in 2 cases; in 1 patient there was an infected bifurcation graft. At a median follow-up time of 11 months the secondary patency rates for axillofemoral and femoro-femoral cross-over bypasses are predicted to be 75%, 71% and 62% after 1, 3 and 5 years, respectively (Kaplan-Meier estimate); on exclusion of vein and composite grafts, the patency rate increases to 79%, 75% and 65%, respectively. Femoro-femoral cross-over grafts seem to produce better results than axillounifemoral grafts (86% versus 77% at 3 years; logrank p greater than 0.05). The patency of the superficial femoral artery providing good run-off conditions, an appropriate technique for performing the anastomoses and adequate choice of graft material appear to improve the results.

[Complicated course of a compression syndrome of the popliteal artery in a 36-year-old patient]. / Komplizierter Verlauf eines Kompressionssyndromes der Arteria poplitea bei einem 36jährigen Patienten.

The popliteal entrapment syndrome is an entity increasingly reported over the past few years. Anatomical variations should be considered if a localized stenosis or occlusion of the popliteal artery is diagnosed in a young, otherwise healthy individual. This case report documents a complicated course of the disease in a young man in whom diagnosis was made only after futile attempts of intraarterial lysis and dilatation at the time of a second operation. A complex crural reconstruction was necessary in order to revascularize the treatment limb.