Modulation by simvastatin of iberiotoxin-sensitive, Ca2+-activated K+ channels of porcine coronary artery smooth muscle cells.

BACKGROUND AND PURPOSE: Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase inhibitors) have been demonstrated to reduce cardiovascular mortality. It is unclear how the expression level of HMG CoA reductase in cardiovascular tissues compares with that in cells derived from the liver. We hypothesized that this enzyme exists in different cardiovascular tissues, and simvastatin modulates the vascular iberiotoxin-sensitive Ca2+-activated K(+) (BK(Ca)) channels. EXPERIMENTAL APPROACHES: Expression of HMG CoA reductase in different cardiovascular preparations was measured. Effects of simvastatin on BK(Ca) channel gatings of porcine coronary artery smooth muscle cells were evaluated. KEY RESULTS: Western immunoblots revealed the biochemical existence of HMG CoA reductase in human cardiovascular tissues and porcine coronary artery. In porcine coronary artery smooth muscle cells, extracellular simvastatin (1, 3 and 10 microM) (hydrophobic), but not simvastatin Na+ (hydrophilic), inhibited the BK(Ca) channels with a minimal recovery upon washout. Isopimaric acid (10 microM)-mediated enhancement of the BK(Ca) amplitude was reversed by external simvastatin. Simvastatin Na+ (10 microM, applied internally), markedly attenuated isopimaric acid (10 microM)-induced enhancement of the BK(Ca) amplitude. Reduced glutathione (5 mM; in the pipette solution) abolished simvastatin -elicited inhibition. Mevalonolactone (500 microM) and geranylgeranyl pyrophosphate (20 microM) only prevented simvastatin (1 and 3 microM)-induced responses. simvastatin (10 microM ) caused a rottlerin (1 microM)-sensitive (cycloheximide (10 microM)-insensitive) increase of PKC-delta protein expression. CONCLUSIONS AND IMPLICATIONS: Our results demonstrated the biochemical presence of HMG CoA reductase in different cardiovascular tissues, and that simvastatin inhibited the BK(Ca) channels of the arterial smooth muscle cells through multiple intracellular pathways.

Protein synthesis inhibition in the basolateral amygdala following retrieval does not impair expression of morphine-associated conditioned place preference.

Conditioned place preference is an animal model used to evaluate the affective properties of natural rewards and drugs of abuse. This animal model is a kind of classical conditioning that depends on learning and memory. The basolateral amygdala (BLA) plays an important role in the consolidation and extinction of memory for this task. However, there is a lack of evidence demonstrating protein synthesis dependent reconsolidation following retrieval in conditioned animals. In other words, is it possible to observe morphine-associated place preference if recall of this preference is disrupted? Accordingly, we investigated this hypothesis by BLA infusion of protein synthesis inhibitor, anisomycin, immediately after retrieval (test) in conditioned place preference paradigm. In the first experiment, the conditioned animals were exposed to the two sides of the apparatus for 15 min in a drug-free state during retrieval. In the second experiment, the animals received an injection of morphine (7.5 mg/kg, i.p.) and immediately after, they were exposed to the two sides of the apparatus for 15 min. Finally in the third experiment, after habituation and training in the conditioned place preference task, the animals received an injection of the unconditioned stimulus (morphine, i.p.; 7.5 mg/kg) followed by confinement for 10 min in the morphine-paired compartment (conditioned stimulus) during memory retrieval. For the three experiments the animals were subsequently exposed in a free-drug state to the two sides of the apparatus for the retest. Our results show that the protein synthesis inhibition in all of these experimental designs had no effect on conditioned place preference memory under conditions that would initiate reconsolidation, suggesting that if reconsolidation of a conditioned place preference task exists it is not mediated by protein synthesis in basolateral amygdala. The effect of anisomycin on consolidation of contextual fear conditioning was also investigated as a positive control to assure that the negative results were not due to methodological problems. Using the same dose of anisomycin (62.5 microg/1 microl) in morphine-associated place preference procedures, we have found that this anisomycin dose blocks the consolidation of contextual fear memory, ruling out the possibility that these negative results can be attributed to methodological problem of some sort.

A comparative study of morphine treatment regimen prior to mating and during late pregnancy.

Pre-mating treatment of female rats with morphine may have long-term effects. In this study, we analyzed the effects of two types of morphine sulfate pre-treatment: during pre-mating (5.0 mg/kg on alternate days for a total of seven doses) and during pregnancy (3.5 mg/(kgday) for 5 days starting on day 17 of pregnancy during early lactation. In order to evaluate possible morphine-induced behavioral changes, dams were tested for maternal behavior and locomotor activity during early lactation, and striatal and hypothalamic concentrations of dopamine and their metabolites and serum levels of corticosterone were measured. Maternal behavior was disrupted only in animals treated with morphine sulfate during pregnancy and challenged acutely (1.5 mg/kg) during lactation. Pre-mating treatment with morphine sulfate-induced changes in responses with increased locomotor activity, striatal dopamine turnover and serum corticosterone levels. None of these parameters were affected by morphine sulfate pre-treatment during late pregnancy. These data suggest that morphine has specific long-term and sometimes addictive-like effects on actively reproductive female animals that vary with the pre-treatment period, late pregnancy being particularly sensitive for effects on maternal behavior.

Video assisted thoracic surgery in the management of spontaneous pneumothorax: the current status.

Over the past decade, video assisted thoracic surgery (VATS) has changed the way spontaneous pneumothorax (SP) is managed. Benefits of VATS include less postoperative pain, shorter hospital stay, and attenuated postoperative inflammatory response are evident compared with open thoracic procedures. Furthermore, the increasing acceptance by patients and referring physicians is testament to its success. Recent studies and the authors decade of experience in management of SP by VATS show that it is quick, safe, and effective, with recurrence rates generally comparable to open procedures, with some exceptions. However, selecting the correct procedure and patient, as well as knowing the limitations of the surgeons and techniques are paramount for success. Even to this day, there are considerable variations in the treatment of SP and large scale controlled studies are needed to better define timing of surgery and the role of the different procedures in the treatment and prevention of SP.

Validation of peptide mapping with electrospray mass spectrometry for recombinant proteins of biopharmaceutical interest and its applications as an identity test and a characterization tool.

In this paper, the steps required to validate a liquid chromatography peptide mapping method with mass spectrometric detection (LC-MS) for use as an identity test and characterization tool are presented. All aspects of peptide mapping are evaluated and optimized, including protein sample preparation (protein reduction, alkylation and enzymatic digestion), high performance liquid chromatography (HPLC) separation of the resulting peptides, and the use of a mass spectrometric detection. In addition, the validation of a single quadruple MS detector is described and the implementation of on-line electrospray ionization MS (ESI-MS) as an adjunct detector to support the investigation of peak differences is presented. Applications of peptide mapping with tandem MS using an electrospray ion-trap instrument throughout the biopharmaceutical product development cycle are discussed, including assessing protein product heterogeneity derived from post-translational modifications (e.g. multiple N- or C-termini, deamidation, oxidation and glycosylation) and protein degradation.

Distinct patterns of genetic alterations in adenocarcinoma and squamous cell carcinoma of the lung.

Squamous cell carcinoma (SqC) and adenocarcinoma (AdC) are the two most common subtypes of non-small cell lung cancer (NSCLC). Cumulative information suggests that the SqC and AdC subtypes progress through different carcinogenic pathways, but the genetic aberrations promoting such differences remain unclear. Here we have assessed the overall genomic imbalances and structural abnormalities in SqC and AdC. By parallel analyses with comparative genomic hybridisation (CGH) on tumorous lung tissues and spectral karyotyping (SKY) on short-term cultured primary tumours, genome-wide characterisation was carried out on 69 NSCLC (35 SqC, 34 AdC). Molecular cytogenetic characterisation indicated common and distinct genetic changes in SqC and AdC. Common events of +1q21-q24, +5p15-p14, and +8q22-q24.1, and -17p13-p12 were found in both groups, although hierarchical clustering simulation on CGH findings depicted +2p13-p11.2, +3q25-q29, +9q13-q34, +12p, +12q12-q15 and +17q21, and -8p in preferential association with SqC pathogenesis (P<0.05). Corresponding SKY analysis suggested that these changes occur in simple and complex rearrangements, and further indicated the clonal presence of translocation partners leading to chromosomal over-representations. These recurring rearrangements involved chromosome pairs of t(1;13), t(1;15), t(7;8), t(8;15), t(8;9), t(2;17) and t(15;20). Of particular interest was the finding that the t(8;12) translocation partner was exclusive to AdC. The combined application of SKY and CGH has thus uncovered the genome-wide chromosomal aberrations in NSCLC. Specific chromosomal imbalances and translocation partners found in SqC and AdC have highlighted regions for further molecular investigation into gene(s) that may hold importance in the carcinogenesis of NSCLC.

Macro-porosity is necessary for the reduction of neointimal and medial thickening by external stenting of porcine saphenous vein bypass grafts.

BACKGROUND: placing external non-restrictive macro-porous stents around porcine vein grafts prevents neointima formation and medial thickening in both the short and long term. Whether the porosity of the stent material influences this effect, however, has not been determined. Therefore, the effect on neointimal and medial thickening of external macro-porous (polyester) and micro-porous (polytetrafluorethylene) stents of equal diameter were compared. The effect on expression of platelet-derived growth factor (PDGF), a potent mediator of vascular smooth muscle cell migration and proliferation and its receptors was also investigated. METHODS AND RESULTS: saphenous vein-carotid artery interposition grafting was performed in Landrace pigs with external placement of 8 mm diameter macro- and micro-porous stents contralaterally. One month after surgery, graft wall dimensions, PDGF and PDGF receptor expression and cell proliferation using proliferating cell nuclear antigen (PCNA) were measured on histological sections. Macro-porous stents significantly reduced neointimal and medial thickening compared with micro-porous stents (0.1+/-0.02 vs. 0.25+/-0.03 mm, P<0.002, and 0.10+/-0.02 vs. 0.17+/-0.02 mm, P<0.014, respectively). Macro-porous stents significantly reduced the percentage of cells expressing PDGF and PCNA, compared with micro-porous stents (36+/-9 vs. 80+/-7, P < 0.002, and 11+/-3 vs. 21+/-2, P < 0.02, respectively). The percentage of cells expressing PDGF receptors was similar with both the stent types. Adventitial microvessel formation occurred across macro-porous stents but was markedly suppressed by micro-porous stents. CONCLUSIONS: porosity is crucial to the efficacy of external stents in reducing neointima formation in porcine vein grafts. Decreases in PDGF expression and cell proliferation accompany the reduction in neointima formation. In addition, macro-porous stents allow adventitial microvessels to connect with the vasculature outside the stent, thereby potentially improving oxygenation. Although external stenting is highly effective in reducing neointima formation after vein grafting, the properties of the stent material necessary for this effect have not been defined. This study establishes that macro-porosity is one essential feature required to reduce PDGF expression cell proliferation and neointima formation.

Characterization of a prostanoid EP3-receptor in guinea-pig aorta: partial agonist action of the non-prostanoid ONO-AP-324.

Contraction of guinea-pig isolated aorta induced by the prostaglandin E analogue sulprostone (1-400 nM) has a lower maximum response (40%) than that of phenylephrine or U-46619 (TP-receptor agonist). A prostanoid EP3-receptor subtype is involved based on agonist potency ranking: equi-effective molar ratios (EMR) are sulprostone (EC50 approximately equal to 23 nM) 1.0, SC-46275 0.11, misoprostol 2.2, gemeprost 3.3, PGE2 5.4, 17-phenyl PGE2 6.0, GR-63799 8.9. GR-63799, which contains a bulky ester group, is relatively more potent on neuronal EP3 preparations than on the aorta. ONO-AP-324, a relative of the non-prostanoid prostacyclin mimetic series, behaves as an EP3 partial agonist on the aorta, inhibiting sulprostone responses but acting synergistically (in a similar manner to sulprostone) with phenylephrine; it may be a useful pharmacological tool for studying EP3-receptors. Sulprostone contractions are markedly suppressed in zero-Ca2+ bathing fluid containing either 2 mM EDTA or 50 microM EGTA, and by Cd2+ (500 microM), but are usually unaffected by nifedipine (0.3 microM) and verapamil (4.44 microM). Influx of Ca2+, but not through L-type Ca2+-channels, appears to be the major contractile mechanism. The guinea-pig aorta is a valuable addition to the vascular EP3 preparations available and may increase our knowledge of the mechanisms whereby Gi-coupled receptors mediate vasoconstriction (c.f. 5-HT1B/D- and alpha2-receptors). The possibility of certain EP3 agonists distinguishing EP3-receptor isoforms is discussed.

Thiopurine methyltransferase activity and the use of azathioprine in inflammatory bowel disease.

BACKGROUND: Azathioprine therapy is discontinued in one-third of patients with inflammatory bowel disease because of toxicity or a lack of clinical response. Patients with thiopurine methyltransferase (TPMT) deficiency are intolerant to azathioprine, whilst carriers are at increased risk of side-effects. AIM: To evaluate the importance of TPMT activity in the management of azathioprine therapy in inflammatory bowel disease. METHODS: Clinical response, adverse effects and haematological parameters were determined and correlated with TPMT enzyme activity and genotype in 106 patients with inflammatory bowel disease. RESULTS: Ninety-six patients had high TPMT activity, and 10 had intermediate activity. Nineteen patients (18%) were intolerant to azathioprine. Fifteen (16%) of those with high TPMT activity were intolerant, compared with five (50%) with intermediate activity [odds ratio (OR), 5.4; 95% confidence interval (CI), 1.5-19.8]. Complete remission was achieved in 63% of cases, and complete or partial remission in 79%. Interestingly, very high TPMT activity (> 14 units/mL red blood cells) was significantly associated with non-response, irrespective of the time on azathioprine (OR, 0.21; 95% CI, 0.07-0.68). TPMT gene mutations correlated with TPMT activity. CONCLUSIONS: Inflammatory bowel disease patients with intermediate TPMT activity have an increased risk of azathioprine toxicity. Conversely, very high TPMT activity predicts treatment failure. TPMT genotype predicted TPMT phenotype in this study.

Thoracoscopic resection of an esophageal cyst in a 4-year-old girl.

Thoracoscopic resection of a 4-cm esophageal cyst was performed in a young child. The patient tolerated the procedure well with little chest wall trauma, and she was discharged on the second post-operative day. At 1-month follow-up, there were no associated complications.

The role of video-assisted thoracoscopic surgery in the management of pulmonary tuberculosis.

Tuberculosis remains a major health problem worldwide. The current role of video-assisted thoracoscopic surgery (VATS) in the management of this condition is unclear. We reviewed our experience over a 36-month period from a single institution. Thirty-seven patients (26 male, 11 female, with age ranging from 22 days to 71 years), in whom the final diagnosis was tuberculosis, underwent VATS procedures. There were 12 pleural biopsies, 3 decortications, 12 wedge lung resections, 5 drainages of empyema, and 5 lobectomies. All the patients were studied prospectively. There were no mortality or intraoperative complications. The overall median postoperative hospital stay was 4 days (range, 2 to 35 days). Postoperative parenteral narcotics requirement (mean, 310 mg meperidine hydrochloride [Pethidine]) was significantly less than a historic group of 30 patients who underwent conventional thoracotomy for lung resection or empyema drainage for tuberculosis (mean, 875 mg). Postoperative complications include 2 persistent air leaks over 7 days (5.4%) and 1 wound infection (2.7%). We conclude the following: (1) VATS is safe and effective in achieving the diagnosis of tuberculosis through pleural biopsies or wedge lung resection of indeterminate pulmonary nodules; it is particularly useful for those patients who are debilitated, thus making them poor candidates for conventional open surgery; (2) in patients with trapped lung or tuberculous empyema, VATS could achieve full lung reexpansion with minimal morbidity; and (3) therapeutic lung resection using VATS in patients with tuberculosis is technically demanding and potentially hazardous. Its role is, at present, limited.

Routine video-assisted thoracoscopy prior to thoracotomy.

We investigated the role of routine video-assisted thoracoscopy (VAT) prior to thoracotomy. From June 1993 to May 1995, we routinely performed VAT prior to all our elective thoracotomies in adults. Patients who planned to have video-assisted thoracic surgery (VATS), those who underwent emergency thoracotomy, and patients younger than 10 years old were excluded from this study. There were 63 patients (47 men and 16 women; age range, 16 to 84 years), of whom 39 (62%) had malignant disease and 24 (38%) had benign disease. In four cases, VAT could not be performed because of either pleural symphysis or inability to adequately collapse the upper lung. In six cases, thoracoscopic findings influenced subsequent management. Pleural metastases were found in two cases that led to abandonment of thoracotomy; in four cases, identification of chest wall involvement by a malignant or benign process led to proper planning of subsequent thoracotomy. There was no added morbidity from this procedure which took, on average, 6.2 min to complete (range, 3 to 17 min). There was no added cost for consumables. We concluded that: (1) routine VAT is a safe procedure; (2) it adds little to the overall cost or operating time; (3) it can provide useful information that could alter subsequent operative strategy. We recommend routine VAT prior to thoracotomy in patients with known or suspected intrathoracic malignancy and those suspected of having chest wall involvement on CT scans.

Study of endoscopic staple formation by specimen radiography on pulmonary wedges.

The advent in video-assisted thoracic surgery has rendered us to rely more and more on mechanical devices. We prospectively studied staple formation on resected lung specimen by radiography and attempted to correlate this with the clinical outcome. From February 1994 to January 1995, 36 consecutive pulmonary wedges (23 apical bullae, 12 pulmonary metastases, 1 tuberculoma) from 31 patients who had undergone resection by endoscopic staple-cutter (Endo GIA30, USSC) were examined by two-plane radiography for staple alignment and closure. Imperfect staple formation was found in 21 (58%) of resected specimens. The median size of the resected bullae is 4.2 mL (range, 2.0 to 58.8 mL) compared with 36 mL (range, 1.2 to 222.8 mL) in the resected metastases and tuberculoma specimen. Despite detecting more imperfect staples in the metastases group (77% vs 57%), there was little difference in the two groups with respect to postoperative chest drainage duration (median, 3 vs 2 days) or hospital stay (median, 2 vs 2 days). We conclude that the currently available endoscopic staplers are by no means perfect, especially for resection of larger specimens, even though this may not be apparent clinically. A continuous search for improvement in endoscopic staplers designed specifically for lung resection is needed.

Video-assisted thoracoscopic thymectomy for myasthenia gravis.

Video-assisted thoracoscopic surgery (VATS) provides a new approach to thymectomy. From June 1993 to December 1994, we performed a total of eight thymectomies for myasthenia gravis (MG). There were four male and four female patients with ages ranging from 9 to 76 years. Three of the eight patients had associated thymoma. We believe that complete thymectomy was accomplished in all cases by examination of the thymic bed and resected specimen. There was no mortality or intraoperative complications. The median postoperative hospital stay was 5 days (range, 2 to 37 days). One patient required ventilatory support postoperatively. Clinical improvement was observed in all patients after a mean follow-up of 10 months (range, 2 to 21 months). Compared with a comparable historical group of patients with MG who underwent transsternal thymectomy, the VATS group was associated with significantly less analgesic requirement and shortened hospital stay. We conclude that VAT thymectomy is technically feasible and is associated with a favorable postoperative course compared with the transsternal approach. We believe that complete thymectomy can be achieved by this approach. Further investigation with long-term follow-up is needed to further clarify the role of VAT thymectomy in thoracic surgery.

Thoracoscopic management of malignant pleural effusions.

Malignant pleural effusion is a common condition and often presents a challenge for treatment. We report our experience from a single institution with the use of video-assisted thoracoscopic surgery (VATS) in the management of malignant effusions. From September 1992 to April 1995, 69 patients (31 men, 38 women; age range, 38 to 76 years) underwent diagnosis and/or treatment of malignant effusions; these included 46 pleural biopsies, 34 talc insufflations, and 16 limited decortications. There was no mortality and there were no intraoperative complications. Postoperative complications occurred in seven patients (10%). Specific histologic diagnoses were obtained in all but 6 patients (87%). Malignant effusion was confirmed in 25 of 46 cases (54%). Thoracoscopic talc insufflation with or without additional decortication was successful in 32 of 34 cases (94%) in controlling recurrence of effusion after a mean follow-up of 6 months among the survivors (22 patients died during the follow-up period without effusion reaccumulation). We conclude that VATS not only provides an accurate diagnosis but also allows effective therapeutic procedures to be performed for malignant effusions that are associated with an acceptable morbidity.

Thoracoscopic lobectomy for benign diseases.

The few reports in the literature on thoracoscopic anatomic lung resections were almost exclusively for early primary lung cancers. We report our combined experience on video-assisted thoracoscopic (VAT) lobectomy for benign diseases from two major hospitals in Hong Kong over a 20-month period. From August 1993 to March 1995, 66 VAT lobectomies were performed; of this number, 10 cases (15%) were for benign diseases (5 tuberculosis, 2 organized pneumonia, 1 bronchiectasis, 1 sclerosing hemangioma, 1 infected bronchogenic cyst). There was no mortality or incidence of intraoperative complications. Postoperative complications occurred in one patient with tuberculosis and consisted of persistent air leak and subsequent wound infection. There were no long-term complications after a mean follow-up of 11 months. The mean duration of chest tube drainage was 6.7 days and that of hospital stay was 9.8 days. These results were not statistically different from those achieved in VAT lobectomies performed for malignant tumors (5.0 days for drainage and 6.8 days for hospital stay) despite the fact that hilar dissection was sometimes more difficult in the former because of inflammatory changes. We conclude that VAT lobectomy for benign diseases is technically feasible even though its role in thoracic surgery remains to be defined.

Results of video-assisted thymectomy in patients with myasthenia gravis.

OBJECTIVE: The efficacy of video-assisted thoracic surgery for thymectomy with myasthenia gravis has not been examined. METHODS: Thirty-three consecutive patients underwent total thymectomy by video-assisted techniques between 1992 and 1995. There were 13 male and 20 female patients with a mean age of 38.42 +/- 16.88 years (range 9 to 84 years). The procedures were performed by either a right (n = 11) or left (n = 22) thoracoscopic approach and all anterior mediastinal tissue was removed. RESULTS: There was no perioperative mortality or long-term morbidity. One patient required conversion of the video-assisted technique to a lateral thoracotomy. All patients except one were extubated immediately. The mean hospital stay was 4.12 +/- 6.07 days (range 1 to 37 days) with a median of 3 days. Mean follow-up is 23.39 +/- 11.72 months (range 4 to 47 months). Clinical improvement was seen in 87.9% (29/33): one of two patients (50%) in stage I, 17 of 19 (89.4%) in stage IIA, eight of nine (88.8%) in stage IIB, and three of three (100%) in stage III. Metaanalysis of these results compared with results in nine published series in which other techniques were used showed no difference in clinical improvement after thymectomy between series. CONCLUSION: We conclude that video-assisted thymectomy is as effective as the traditional open surgical approaches for performance of thymectomy in the management of patients with myasthenia gravis. In addition, the improved cosmesis of the video-assisted approach ideally will lead to earlier thymectomy in patients with myasthenia gravis.

Upper T mini-sternotomy for aortic valve operations.

OBJECTIVES: New minimally invasive approaches for cardiac surgical procedures are constantly being developed in the hope of decreasing patient morbidity and enhancing the postoperative recovery. This report reviews the use of an upper T mini-sternotomy approach to aortic valve surgery. PATIENTS: Nine consecutive nonselected patients (5 men, 4 women, mean age, 66 years) underwent isolated aortic valve replacement with the use of this approach. Two patients had isolated aortic valve stenosis, three had isolated aortic valve incompetence, and four patients had mixed aortic valve disease. RESULTS: In all cases, an excellent view of the aortic valve was obtained, aortic valve replacement with a bileaflet mechanical prostheses was performed, and no intraoperative difficulties were encountered. Mean aortic cross-clamp time was 83 min and mean cardiopulmonary bypass perfusion time was 97 min. All patients were extubated in the operating room at the end of the surgical procedure, and there were no postoperative complications. All patients were discharged home on postoperative day 3, and there were no late complications. CONCLUSION: Through an upper T mini-sternotomy, aortic valve surgery can be performed in the conventional manner using standard surgical instruments with no alteration in cardiopulmonary bypass and myocardial protection routines. With this method, postoperative pain is reduced and patient recovery is expeditious.

Can CT scanning be used to select patients with unilateral primary spontaneous pneumothorax for bilateral surgery?

STUDY OBJECTIVES: Despite advances in the surgical treatment of spontaneous pneumothorax, the timing of surgical intervention continues to be a subject of controversy. We test the hypothesis that CT scanning can help to predict the probability of the occurrence of primary spontaneous pneumothorax (PSP) by detecting lung bullae. DESIGN: Prospective, longitudinal cohort study. PATIENTS AND METHODS: Between May 1994 to March 1995, 28 consecutive patients (23 men; age range, 18 to 47 years; mean, 29 years) with unilateral PSP who were to undergo video-assisted thoracic surgery (VATS) received preoperative CT of the thorax. CT scans were interpreted by one radiologist blinded to the clinical data for the presence of bullae in both lungs. All patients were followed-up in our outpatient clinic for an average of 59.0 months (range, 54 to 64 months). RESULTS: Eighty-eight percent of the blebs or bullae identified intraoperatively were demonstrated on preoperative CT scans. CT scans also showed the presence of lung blebs or bullae in the contralateral lung in 15 patients (53.6%). During the follow-up period, 4 of these 15 patients (26.7%) with contralateral blebs developed PSP in the untreated lung; none of the patients who did not have contralateral blebs (n = 13) developed PSP (p = 0.04 [chi(2) analysis]). CONCLUSIONS: The detection of lung bullae by CT scanning in the contralateral lung following unilateral PSP is associated with a higher rate of subsequent occurrence of pneumothorax in that lung. Thus, CT scanning can be used to predict the risk of occurrence of this condition, allowing preemptive surgical intervention in selected patients.

Video-assisted thoracoscopic anatomic lung resections. The initial Hong Kong experience.

We report our combined experience on video-assisted thoracoscopic (VAT) anatomic lung resections from two major hospitals in Hong Kong over a 17-month period. From August 1993 to December 1994, 82 cases of major lung resections were attempted using the VATS approach, of which 60 were successfully completed (55 lobectomies, 2 bilobectomies, 2 pneumonectomies, and 1 segmentectomy). Of these 60 cases, there were 43 men and 17 women with a mean age of 66 years (range, 37 to 85 years). The final pathologies were 52 primary lung cancers (37 adenocarcinoma, 11 squamous cell carcinoma, 2 bronchoalveolar carcinoma, 1 adenosquamous carcinoma, and 1 undifferentiated carcinoma); 1 pulmonary metastasis (from nasopharyngeal carcinoma); and 7 benign lesions (3 tuberculosis, 1 bronchiectasis, 1 sclerosing hemangioma, 2 organizing pneumonia). There was one postoperative death (mortality rate, 1.8%). Complications include persistent air leak over 10 days (four), wound infection (two), supraventricular tachycardia (three), and recurrence of tumor over the utility thoracotomy scar (one). All the patients were followed up from 8 weeks to 19 months (mean, 10 months). The mean duration of chest drainage was 5.4 days (range, 2 to 25 days). The mean hospital stay was 7.2 days (range, 4 to 35 days). The average postoperative parenteral narcotic (meperidine hydrochloride [Pethidine]) requirement by patient-controlled analgesia was 275 mg (range, 75 to 800 mg). This compared favorably with an age- and sex-matched historic group of patients who underwent posterolateral thoracotomy and had a hospital stay of 10.4 days (statistically non-significant) and narcotic requirement of 950 mg (statistically significant by paired t test). We conclude that VAT anatomic lung resection is technically feasible. However, there are some specific complications associated with major lung resection through minimal access. Refinement of our present technique and attention to details are important to improve our results.