Guillermo Ramos

Early Complications in Surgical Treatment of Lung Cancer: A Prospective, Multicenter Study

BACKGROUND We prospectively analyzed the postoperative morbidity, mortality rate, and risk factors in 605 patients who underwent thoracotomy for bronchogenic carcinoma. METHODS Patients were categorized by postsurgical tumor stage: I, 287 patients (47.4%); II, 49 patients (8.1%); IIIA, 154 patients (25.5%); IIIB, 80 patients (13.2%); IV, 16 patients (2.7%); unavailable, 19 patients (3.1%). Two hundred ninety-four patients (48.6%) underwent lobectomy, 172 (28.4%) pneumonectomy, 20 (3.3%) bilobectomy, 29 (4.8%) segmentectomy, 27 (4.5%) wedge resection, and 63 (10.4%) exploratory thoracotomy. The importance of the factors that influence the morbidity and mortality rates was calculated from their relative risks. Univariate and multivariate methods for a logistic regression model were used for this analysis. RESULTS Postoperative complications developed in 196 patients (32.4%); there were 165 (27.3%) cases of operation-related complications and 152 (25.1%) cases of respiratory and cardiovascular complications. The morbidity rate was highest in patients with preexisting vascular disease (50.9%; odds ratio [OR], 2.20) or insulin-dependent diabetes mellitus (52.4%; OR, 2.77) and in patients who underwent pneumonectomy (40.1%; OR, 1.82). Forty patients (6.6%) died postoperatively, most commonly of respiratory failure (67.5%). The mortality rate was highest in patients with postoperative morbidity (OR, 31.9) or vascular disease (15.8%; OR, 2.83) and in patients who underwent pneumonectomy (13.4%; OR, 4.9). CONCLUSIONS Postoperative complications are more likely to develop in patients with peripheral vascular disease or insulin-dependent diabetes mellitus, or both. Postoperative mortality was found to be significantly higher in patients with vascular disease and those who underwent pneumonectomy.

Prognostic factors in neuroendocrine lung tumors: a Spanish multicenter study

Background. This study examines the experience of the Spanish Multicenter Study of Neuroendocrine Tumors of the Lung through the clinical data and behavior of patients treated for this pathologic process. Methods. From 1980 to 1997, 361 cases of neuroendocrine carcinomas (NEC) were treated surgically. Patients were enrolled in a protocol using the pathologic and follow-up reports. According to Dreslers’ criteria, the cases were segregated into grade 1 (typical carcinoid), grade 2 (atypical carcinoid), grade 3 large cell type, and grade 3 small cell type. Several variables were reviewed in all patients. Statistical analysis was performed to determine whether clinical characteristics and differentiation were associated with significant differences in the prognosis. Results. A total of 261 cases of NEC were identified with grade 1, 43 with grade 2, and with grade 3: 22 of large and 35 of small cells. Five-year survival for different grades was as follows: grade 1, 96%; 2, 72%; 3 large cell type, 21%; and 3 small cell type, 14%. When a comparative analysis between typical and atypical carcinoids was performed a significant difference for mean age, tumor size, nodal metastases, and recurrence was observed. However, female sex, nodal metastases, and recurrence rate differed between atypical carcinoids and grade 3 NEC of large cells. A difference in recurrence rate was found between patients with both types of grade 3 NEC. Conclusions. The progressive deterioration of tumor organization highlights that neuroendocrine tumors constitute a continuous spectrum. A careful observation of pathologic findings is necessary to individualize their prognostic factors.

Hydatid cyst of the lung: diagnosis and treatment.

Hydatid infestation of the lung can be primary or secondary. In three of four cases the cyst is a single one. Hydatidosis of a different location, particularly the liver, may be associated. The period of initial growth of primary hydatidosis is frequently asymptomatic. Bronchial fistulization is an important event in the evolution of the cyst. Intrapleural rupture constitutes a rare eventuality, but it is often as characteristic as it is severe. Secondary, metastatic hydatidosis, due to breaking of a primary visceral cyst in a vein or heart, is rare. A special form is so-called multiple malignant pulmonary hydatidosis, which causes progressive respiratory deficiency and right ventricular failure. There are a variety of radiographic images. Ultrasonography, computed tomography, and magnetic resonance imaging can recognize certain details of the lesions and discover others that are not visible by conventional radiography. For a specific serologic diagnosis, our experience favors the immunoglobulin G enzyme-linked immunosorbent assay and immunoelectrophoresis. Treatment is essentially surgical. In general, chemotherapy is used as a complement to operative treatment to avoid recurrence. Surgery has two objectives: to remove the parasite and to treat the bronchipericyst pathology and other associated lesions. The prognosis has changed during the last few years, and results are now commonly satisfactory. The most frequent complications are pleural infection and prolonged air leakage. Operative mortality does not exceed 1% to 2%. Despite the low mortality and the limited recurrence rate, it is necessary to remember the invading character of pulmonary hydatid disease, which sometimes makes therapy difficult and questionable. Prophylaxis is essential to eradicate the disease completely. Hydatid disease, still endemic in many countries, is an anthropozoonosis that has been known for centuries [1]. Hence there is no need to emphasize its importance from a sanitary point of view [2, 3]. Humans are accidental intermediary hosts in the biologic cycle of the taenia Echinococcus granulosus, which is the most frequent hydatidosis etiologic agent in our environment [4, 5]. The development of the parasitic larval stage in the host’s organs manifests in the form of a cyst (hydatid); in a way, the expression “hydatid cyst” is redundant, although it has become widespread [1]. Lung involvement, which follows hepatic infestation in frequency, has been seen in 30% of the cases of hydatidosis in some series [6]. It constitutes an important chapter in pathology, as much for the diversity of the anatomoclinical forms it produces as for the problems of diagnosis and therapy it creates. The disease is usually found at an early age; in most cases before 40 years, with all the socioeconomic implications this entails [7]. Regarding gender, like other authors [8–10] we have noted a predominance in males over females; and based on its etiology, there is a higher incidence in rural populations [11]. Pathogenesis, Pathology, Pathologic Physiology

Evaluation of six serological tests in diagnosis and postoperative control of pulmonary hydatid disease patients

Latex agglutination (LA), passive hemagglutination (PHA), immunoelectrophoresis (IEP) and specific IgE, IgM, IgG enzyme-linked immunosorbent assay (ELISA) tests for diagnosis and postoperative follow-up of 79 patients with surgically confirmed pulmonary hydatidosis were evaluated. Specific IgG ELISA was the most sensitive test (83.5%) and the least sensitive tests were specific IgE ELISA (44.3%) and IEP (50.6%). The specificity obtained for all the serologic test was above 97% in all cases. The greatest number of false positives in all tests (except IEP) occurred in patients with Taenia saginata and Taenia solium cysticerci infestations and in patients with lymphoma and leukemia. Specific IgG ELISA demonstrated the highest negative predictive value (93.8%). No statistically significant differences (p > 0.050) were found in the sensitivity of the tests when patients with only one cyst and patients with various cysts were compared. Considering only the patients without relapse, the percentage of seropositive patients increased in all tests at 1 and 3 months after surgery. After that time the percentage of seropositive patients decreased. At 48 months after surgery all patients without relapse became negative in IEP, specific IgE ELISA, and specific IgM ELISA. The antibody titers in all seropositive patients increased during the 3 months after surgery. From these 3 months onward, antibody levels decreased in all serologic tests studied in the group of patients without relapse. The patients who had relapses during the first year after surgery presented persistently elevated antibody titers in all postoperative sera. The antibody titers of the patients who relapsed between the third and fourth years after surgery decreased progressively the third month after surgery, and increased in the serum obtained at the moment of relapse diagnosis. Our results show that persistence of elevated antibody titers in patients with pulmonary hydatidosis in the year after surgery or titer increase after a progressive decrease are indicative of relapse or reinfection.

Open-Window Thoracostomy and Thoracomyoplasty to Manage Chronic Pleural Empyema

BACKGROUND The purpose of this study is to report our 15-year experience treating chronic empyemas after pulmonary resection and tuberculosis. METHODS Open-window thoracostomy and thoracomyoplasty were used to treat 40 patients with chronic pleural empyema characterized by residual empyematic cavity, bronchopleural fistula, and persistent pleural infections that were secondary to tuberculosis (n = 22) or pulmonary resection (n = 18). Between 2 and 7 months after thoracostomy, thoracomyoplasty was performed to eliminate a persistent pleural cavity. In 2 patients with postpulmonary resection empyema and a large bronchopleural fistula, intrathoracic transposition of the latissimus dorsi flap and open-window thoracostomy were performed simultaneously to close the fistula. RESULTS The pleural space was eliminated per primam intentionem in 21 of 22 patients with tuberculosis and in 14 of 18 with a postpulmonary resection empyema. Another myoplasty was performed in an additional 3 patients to eliminate the pleural space. During open-window thoracostomy, the latissimus dorsi muscle was preserved with minimal injury to the anterior serratus muscle. One patient died postoperatively. CONCLUSIONS Successful treatment of chronic pleural empyema requires adequate timing of surgical procedures. Our two-procedure technique is relatively simple and safe.

Usefulness of Four Different Echinococcus granulosus Recombinant Antigens for Serodiagnosis of Unilocular Hydatid Disease (UHD) and Postsurgical Follow-Up of Patients Treated for UHD

ABSTRACT Four different recombinant antigens derived from Echinococcus granulosus, designated B1t, B2t, E14t, and C317, were tested with enzyme-linked immunosorbent assays (ELISAs) for the detection of specific immunoglobulin G (IgG) in patients with unilocular hydatid disease (UHD). The results were compared to those obtained with hydatid fluid and were subjected to receiver operator characteristic analysis. The diagnostic performance of the above-listed proteins was defined with respect to their specificity, sensitivity, and predictive values (PV); the influence of cyst location; and usefulness in the follow-up of surgical treatment for UHD and in the determination of whether or not patients have been surgically cured of UHD. The best diagnostic results were obtained with the anti-B2t IgG ELISA, with 91.2% sensitivity, 93% specificity, and high positive and negative PV (89.4 and 94.2, respectively). In addition, this diagnostic tool proved to be useful for the follow-up of surgically treated UHD patients. The anti-B2t IgG ELISA may find an application in the serodiagnosis of UHD in clinical laboratories.

Quistes hidatídicos de mediastino: 8 casos

La hidatidosis en el ser humano es una enfermedad parasitaria producida por el crecimiento quistico de la larva de la tenia Echinococcus granulosus . Los organos mas afectados son el higado y el pulmon. La localizacion mediastinica es muy rara y se han descrito aproximadamente 100 casos en la bibliografia. Presentamos 8 casos de quistes hidatidicos de mediastino (QHM) intervenidos en un periodo de 21 anos. La distribucion fue similar en ambos sexos. La edad oscilo entre 10 y 74 anos. En los QHM la sintomatologia depende del tamano, localizacion y afectacion de estructuras proximas. La complicacion mas grave es la rotura del quiste y el paso del material hidatidico a la sangre, lo que puede provocar shock anafilactico e incluso la muerte del paciente. Actualmente, la ecografia, la tomografia computarizada (TAC) y la resonancia magnetica (RM) facilitan el diagnostico. El tratamiento es la exeresis del quiste y de la periquistica. Se debe sospechar QHM en las lesiones quisticas mediastinicas en paises de alta incidencia de hidatidosis. Hydatidosis in humans is a parasitic disease produced by cystic growth of the larvae of the tapeworm Echinococcus granulosus, affecting mainly the liver and lung. Larvae are rarely present in the mediastinum, although approximately 100 cases have been described in the literature. We report eight cases of hydatid cysts of the mediastinum (HCM) treated surgically over a period of 21 years. The incidence was similar in males and females and ages ranged from 10 to 74 years. Symptoms depend on size, location and involvement of neighboring structures in HCM. The most serious complication is cyst rupture with consequent transfer of hydatid material to the blood, possibly causing anaphylactic shock and even death. Currently, sonography, computed tomography and magnetic resonance images facilitate diagnosis. Treatment involves excision of the cyst and pericystic tissue. CHM should be suspected when mediastinal cysts are found in countries where the incidence of hydatidosis is high.

Improved Serodiagnosis of Cystic Echinococcosis Using the New Recombinant 2B2t Antigen

A standardized test for the serodiagnosis of human cystic echinococcosis (CE) is still needed, because of the low specificity and sensitivity of the currently available commercial tools and the lack of proper evaluation of the existing recombinant antigens. In a previous work, we defined the new ELISA-B2t diagnostic tool for the detection of specific IgGs in CE patients, which showed high sensitivity and specificity, and was useful in monitoring the clinical evolution of surgically treated CE patients. Nevertheless, this recombinant antigen gave rise to false-negative results in a percentage of CE patients. Therefore, in an attempt to improve its sensitivity, we constructed B2t-derived recombinant antigens with two, four and eight tandem repeat of B2t units, and tested them by ELISA on serum samples of CE patients and patients with related parasites. The best diagnostic values were obtained with the two tandem repeat 2B2t antigen. The influence of several clinical variables on the performance of the tests was also evaluated. Finally, the diagnostic performance of the 2B2t-ELISA was compared with that of an indirect haemagglutination commercial test. The 2B2t recombinant antigen performed better than the HF and B2t antigens, and the IHA commercial kit. Therefore, this new 2B2t-ELISA is a promising candidate test for the serodiagnosis of CE in clinical settings.

Hemodynamic and cerebral repercussions arising from surgical interruption of the superior vena cava: Experimental model

This study was designed to analyze the hemodynamic and cerebral repercussions arising from the surgical interruption of the superior vena cava. The experiments were carried out in 12 mongrel dogs under two different conditions: with shunt (group A, n = 6) and without the installation of a shunt (group B, n = 6). The period of occlusion was 35 minutes. The right atrium pressure, pulmonary arterial pressure, and aortic pressure are not significantly modified in the two groups. The intracranial pressure had an important correlation with the central venous pressure (r2 = 0.8572). In group B, the intracranial pressure had a sharp increase between the basal period (6.9 +/- 1.47 mm Hg) and the clamping superior vena cava (17.2 +/- 1.05 mm Hg), accentuated with the interruption of the azygous vein (32.2 +/- 0.7 mm Hg). In group A, the use of a shunt avoided this alteration during clamping of the superior vena cava (6.8 +/- 2.0 mm Hg) and the azygous vein (8.0 +/- 2.24 mm Hg). However, after removal of the clamps in group B, an elevated residual intracranial pressure was observed (21.1 +/- 3.33 mm Hg) in contrast to the central venous pressure, which returned to the basal values (4.4 +/- 0.7 mm Hg). The biomechanic findings of the volume-pressure curves (with Miller and Marmarou-Shapiro tests) and the cerebral necropsy showed brain damage in group B, without the shunt. Three animals had areas of hemorrhagic infarction. Histologic study demonstrated signs the incipient vasogenic edema. In group A, all findings were compatible with the normal. In conclusion, these results suggest the importance of shunting the blood in those cases of a nonobstructed superior vena cava because the clamping and reconstruction produce hemodynamic compromise and brain damage.

Epidural regional hypothermia for prevention of paraplegia after aortic occlusion : experimental evaluation in a rabbit model

PURPOSE The efficacy of epidural regional hypothermia in the prevention of acute and delayed-onset paraplegia, as well as possible complications and limitations of this technique to a clinically acceptable form, were evaluated in 49 New Zealand white rabbits. METHODS A modified rabbit spinal cord ischemia model of infrarenal aortic occlusion for 30 minutes was employed. The study was performed in two phases. In phase I (n=20), regional hypothermia induced by epidural perfusion of iced normal saline solution (4 degrees C) was tested versus control in 10 rabbits each (groups A and B). In phase II (n=29) the animals were subdivided into three groups to study the kinetics of absorbtion and distribution of methylene blue (group C; n=10), radiographic contrast material (group D; n=9), and measurement of cerebrospinal pressure while an epidural iced solution was or was not infused (group E; n=10). RESULTS At 24 and 48 hours, all of the normothermic animals showed irreversible paraplegia (Tarlov score 0). In contrast, at 24 hours none of the rabbits undergoing epidural cold infusion were paraplegic, although at 48 hours one animal had weakness of a hindlimb (Tarlov score 3). Plasma concentration-time profiles of a continuous epidural perfusion with methylene blue showed that the spinal canal is a highly compliant space. Epidurographs showed that epidural perfusion tends to spread more in a cephalic than caudal direction and the main uptake is by the vascular compartment. Despite the large volumes infused (78.75 ml/hr; range, 50 to 100 ml), we observed only a modest transient increase in cerebrospinal fluid pressure (from 2.5 +/- 0.3 mm Hg to 5.4 +/- 0.1 mm Hg), although some animals had intracranial hypertension. CONCLUSIONS Regional hypothermia induced by epidural cold perfusion has a highly protective effect against the ischemic spinal cord damage. However, this method probably does not avoid the risk of delayed-onset paraplegia. An important limitation of this technique is the difficulty of controlling the intrathecal pressures.