Ulrich Althaus

Three years' experience in video-assisted in thoracic surgery (VATS) for spontaneous pneumothorax

In a prospective study (June 1990 to June 1993), 79 patients were treated for spontaneous pneumothorax by video-assisted thoracoscopic methods with regular follow-up. The observation time was from 3 to 36 months (mean 19.6 months) and was more than 24 months in 27 patients. In 57 patients spontaneous pneumothorax was primary and in 22 secondary. The 53 male and 26 female patients were aged between 17 and 87 years (mean 37 years). Twenty-one patients were treated thoracoscopically for first episode, 22 for persistent pneumothorax (> 7 days), and 36 for a recurrence. Endoscopic examination failed to reveal any lung alteration in four patients (5.1%), and treatment then consisted of simple drainage. Leaks were sealed 26 times by means of a Roeder loop with local anesthesia and 14 times by wedge resection with endotracheal anesthesia and one-lung ventilation; 34 patients were treated by pleurectomy. No deaths occurred. Surgical morbidity was 3.8%, and the postoperative complication rate was 5.1%. One patient was excluded from the follow-up study after conversion to a thoracotomy for control of arterial bleeding. We noted six recurrences; four occurred in the first 21 days and three after ligation of the leak with a Roeder loop. We conclude that video-assisted thoracoscopic treatment of spontaneous pneumothorax by wedge resection and pleurectomy has a recurrence-free rate of 93.8% (45/48) and is therefore an effective treatment for all forms of spontaneous pneumothorax.

Thoracotomy and thoracoscopy: postoperative pulmonary function, pain and chest wall complaints.

OBJECTIVE Two different surgical accesses combined with standard pain management procedures are compared regarding early and intermediate pulmonary function and pain relief. METHODS In a prospective study, 15 consecutive patients undergoing video-thoracoscopy for pulmonary wedge resection (group 1) were matched to 15 patients undergoing standard postero-lateral thoracotomy for lobectomy (group 2) according to age, gender and preoperative pulmonary function. Postoperative pain control consisted of patient controlled analgesia in group 1 and epidural analgesia in group 2. Pain intensity was scored from 0-4. The predicted postoperative pulmonary function (FVC and FEV 1) after lobectomies was calculated from the preoperative value according to the extent of resection. A clinical measurement was obtained after a mean follow-up time of 4.2 months. RESULTS The ratios of postoperative measured to predicted values of FVC and FEV1 for group 1 compared with group 2 were 0.64 +/- 0.15 and 0.65 +/- 0.14 compared with 0.60 +/- 0.19 and 0.59 +/- 0.13, resp. (both n.s.) at the first day postoperative; 0.92 +/- 0.18 and 0.95 /- 0.17 compared with 0.76 +/- 0.20 (P < 0.05) and 0.83 +/- 0.23 (n.s.), resp. at hospital discharge; 0.98 +/- 0.10 and 0.94 +/- 0.14 compared with 1.01 +/- 0.17 (n.s.) and 1.10 +/- 0.17 (P < 0.05), resp. at follow-up. Pain intensity score one day after surgery ranged from 0.4 (resting position) to 1.6 (coughing) for group 1, and from 0.3 to 1.2 for group 2. Thirty-six percent of the thoracoscopy patients and 33% of the thoracotomy group complained of persistent pain or discomfort on the site of the operation after 3-18 months. CONCLUSION Post-thoracotomy pain can be effectively controlled with epidural analgesia and pain intensity is no higher than in patients after thoracoscopy who are managed with patient controlled analgesia. FVC is slightly more decreased after thoracotomy during the early postoperative period. FVC and FEV 1 approach the predicted values after four months in both groups. The rate of persistent pain is similar after thoracoscopy and thoracotomy.

Transit-time flow measurement for detection of early graft failure during myocardial revascularization

BACKGROUND A low-flow situation in arterial and venous grafts has been associated with high rates of perioperative infarction and mortality. This study was designed to look at intraoperative graft flow and resistance in patients with coronary artery disease. METHODS Coronary artery bypass graft flow was measured in 46 patients. Transit-time flow was used for coronary flow measurements at rest as well as after maximal vasodilation with adenosine infusion. RESULTS Forty-three of the 46 patients showed normal internal mammary artery graft flow (>20 mL/min); 3 patients had no or minimal graft flow. Redoing the graft anastomosis in these 3 patients resulted in normalization of graft flow. The mean flow increased significantly after correction from 0.5 +/- 0.7 mL/min to 15.7 +/- 9.6 mL/min (p < 0.02). Conversely, vascular resistance decreased significantly from 138 +/- 10 to 4.8 +/- 1.8 Ohmv (p < 0.0001), as did the pulsatility index (from 146.9 +/- 95.7 to 3.4 +/- 1.8; p < 0.001). After correction, coronary flow reserve was 2.5 +/- 1.1. CONCLUSIONS Measurements of intraoperative flow and resistance as well as derived variables allow assessment of early graft function and thus help prevent graft failure and reduce perioperative infarction. Transit-time volume flow might be a simple tool for quality control in coronary bypass procedures.

Early and late outcome of operated and non-operated acute dissection of the descending aorta.

OBJECTIVE At present debate continues concerning the optimal mode of treatment for type B dissections. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed early and long-term outcome of acute dissection of the descending aorta treated by emergency aortic replacement, medical treatment or delayed surgery. METHODS Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. A total of 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were: rupturing aneurysm (n = 15), diameter of the descending aorta (n = 13), malperfusion of the thoracoabdominal aorta (n = 8) and pseudocoarctation syndrome with uncontrollable hypertension (n = 2). All other patients (n = 187) underwent primary conservative treatment on the intensive care unit, including appropriate anti-hypertensive medication. In 12 of them, surgery was denied because of age or significant concomitant diseases. RESULTS Hospital mortality after urgent or emergency surgery was 21% (8/38 patients) for the overall time period. There has been a significant decrease in hospital mortality during the last 5 year-period (12% versus 30% between 1980 and 1994). Causes of death were: cardiac failure in 3, bleeding complications in 2, postoperative mesenteric ischemia in 2 and septicemia in one patient. From the 30 operative survivors, 9 (30%) patients required further surgery on the native aorta after a mean follow-up of 48 +/- 13 months. Hospital mortality during conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14, thoraco-abdominal malperfusion in 13 and cardiac failure in 3 patients, whereas in 3 patients, the cause of death could not be evaluated. In this group, 9 patients had to be shifted to early surgery during the initial hospitalization because of impending rupture (n = 4), rapidly increasing diameter (n = 2) and suspicion of intestinal ischemia (n = 3). After hospital discharge, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% (4/47 patients). Actuarial survival rates after surgery during the first admission were 85 +/- 6% at 5 years and 61 +/- 8% at 10 years, versus 76 +/- 5 and 50 +/- 7% respectively, following conservative treatment (P < 0.001). CONCLUSION Nowadays, acute type B dissection can be treated surgically with a reasonable perioperative risk. Despite aggressive anti-hypertensive treatment, hospital mortality of primary conservative treatment is still high and a substantial percentage of patients requires surgery during initial hospitalization. Main causes of death in both groups are rupture and abdominal malperfusion: therefore, closed clinical and radiologic assessment of the whole thoraco-abdominal aorta is of utmost importance. Long-term results are satisfying; unlimited radiographic follow-up allows for detection of potential severe complications and for proper planning of elective reoperations when indicated.

Intraoperative photodynamic therapy with m‐tetrahydroxyphenylchlorin for chest malignancies

Since there is no satisfactory treatment modality for diffuse malignant mesothelioma of the chest, we assessed surgical tumor resection followed by intraoperative photodynamic therapy with mTHPC in a phase I study.

Accidental deep hypothermia with cardiopulmonary arrest: extracorporeal blood rewarming in 11 patients.

Sixteen patients (age 13-53 years) with accidental deep hypothermia have been rewarmed in our clinic during the last 10 years, 14 by femoro-femoral cardiopulmonary bypass (CPB) of whom 11 had a cardiopulmonary arrest (asystole in 5 and ventricular fibrillation in 6). On admission, the latter were clinically dead showing wide non-reactive pupils and being supported by ventilation and external heart massage. In the survivors, the mean length of cold exposure was 4.4 h (2-5.5 h) and mean arrest interval until initiation of CPB was 2.5 h (1.4-3.7 h). Rectal temperature on admission ranged from 17.5 degrees C to 26 degrees C (mean 22.5 degrees C). The causes for hypothermia were fall into a crevasse (5), avalanche (1), drowning (2) and cold exposure (3) including 2 suicide attempts. Results are summarized in the following table: [table: see text] Eight of the 11 patients with deep hypothermia and cardiac arrest were rewarmed and resuscitated successfully with CPB. Three patients, including 2 cases of asphyxia (avalanche and drowning), could not be weaned from CPB despite adequate rewarming. The other drowned patient (53 years) died on the 3rd postoperative day (POD) from ARDS. The main complication was pulmonary edema (57%) and transient neurological deficits. All survivors became conscious during the first POD and resumed, their professional activity. We conclude that patients with accidental deep hypothermia and even prolonged cardiopulmonary arrest should be rewarmed and resuscitated rapidly by cardiopulmonary bypass. These measures are very promising particularly if the cause of accident and the circumstances suggest that cardiopulmonary arrest was induced by hypothermia alone without other asphyxiating mechanisms.

Acute traumatic rupture of the thoracic aorta: immediate or delayed surgical repair?

The appropriate management of traumatic aortic rupture is often difficult to determine, particularly if the rupture is associated with severe additional lesions. Between 1986 and 1991, ten consecutive patients with acute traumatic rupture of the thoracic aorta (ATRTA) and concomitant injuries were initially treated medically and submitted to delayed aortic repair. Within the same period no other patient had emergency reconstruction of the thoracic aorta. Diagnosis of ATRTA was established immediately after admission in eight patients. Five patients underwent emergency surgery for severe concomitant injuries. With regard to the aortic lesion, all patients were managed medically and submitted to pharmacological treatment in an attempt to reduce cardiac shear forces. None of the patients developed clinical signs of imminent free rupture while waiting for aortic surgery. In the absence of a significant hemothorax and when no coarctation syndrome is evident, the risk of free aortic rupture is considered to be rather low if the patient reaches the hospital in a stable circulatory condition. Postponement of aortic reconstruction is particularly indicated when severe concomitant lesions preclude safe immediate repair of the aortic tear. Following the patients recovery from associated major injury, aortic surgery can be performed as a low risk procedure using cardiopulmonary bypass which is recognised as the most effective technique to prevent spinal cord ischemia and to reduce the risk of paraplegia.

Different techniques of distal aortic repair in acute type A dissection: impact on late aortic morphology and reoperation

OBJECTIVE To compare three different techniques of distal aortic repair in acute type A (de Bakey type I) aortic dissection and to evaluate their impact on the late morphology of the aortic arch and descending aorta and on the incidence of reoperation. METHODS From 65 patients operated on due to an acute type A aortic dissection between 1989 and 1993, 54 long-term survivors underwent clinical and radiologic follow-up examination after a mean postoperative interval of 62+/-16 months. The surgical techniques of distal aortic reconstruction included closed repair using Teflon felt reinforcement under moderate hypothermic cardiopulmonary bypass (n = 20) and open repair in deep hypothermic circulatory arrest using either Teflon felt reinforcement (n = 16) or gelatin-resorcin-formaldehyde (GRF) glue (n = 18) to readapt the dissected aortic layers. In all patients, MR imaging was performed on a 1.5-T whole body imaging system for the evaluation of the morphology and function of the heart, aorta and supraaortic branches. RESULTS Overall hospital mortality following surgical repair of type A aortic dissection was 15.4% during this time period. The highest rate of persistent false lumen perfusion (17/20, 85%) and presence of an intimal flap in the aortic arch (13/20, 65%) was observed in patients following closed repair of acute ascending aortic dissection, whereas the lowest rate of such findings was demonstrated in patients who had undergone open distal aortic repair using biological glue (false lumen perfusion 10/18, 55% and intimal flap in the arch 2/18, 11%). Redo-surgery was significantly reduced in the open repair group using GRF glue (1/18, 5.5%) as compared with the Teflon felt repair group (3/16, 18%) and the closed repair group (6/20, 30%). CONCLUSIONS In patients with acute type A dissection, open distal aortic repair using GRF-glue favourably influences both (1) the severity of late morphologic alterations in the downstream aorta and (2) the incidence of reoperation.

Transit time flow measurement: experimental validation and comparison of three different systems

BACKGROUND Bloodflow measurements are of major clinical importance for quality control in vascular surgery. They allow detection of low-flow situations which may influence outcome adversely. The purpose of the present study was to validate three different flow systems for measuring absolute blood flow. METHODS Measurements were performed in an experimental flow model using arteries and veins and blood or saline at two different temperatures. As a reference method true flow was measured by volume sampling. RESULTS Correlation coefficients between transit time flow and true flow measurements ranged between 0.71 and 0.92. Systematic overestimation and underestimation of transit time flow were observed, but after second-order correction all correlations were excellent, ranging from 0.93 to 0.95 irrespective of flow medium and temperature. CONCLUSIONS Transit time flow measurements are exact and reproducible. Second-order correction yields good accuracy and high precision, with minimal differences among the three systems evaluated.

Prevention of neointimal proliferation by immunosuppression in synthetic vascular grafts

OBJECTIVE Immunosuppressive agents have been proposed to reduce neointimal hyperplasia in synthetic vascular grafts. Thus, the purpose of the present study was to evaluate the safety and efficacy of rapamycins (systemic vs. local vs. oral administration) and mycophenolate mofetil (MMF) to reduce intimal hyperplasia in infrarenal synthetic vascular grafts of the rat. METHODS Fifty-four Wistar rats (250 g) completed the study after a synthetic vascular graft (ePTFE, Gore-tex, 2 mm diameter, 10 mm length) was implanted end-to-end in the infrarenal aorta. The animals were divided into three groups: group 1 consisted of 12 control animals, group 2 consisted of 37 rats receiving rapamycins, either per os (RAD, 1.5 or 3 mg/kg), intraperitoneally (RPM, 1.5 or 3 mg/kg) or locally (RPM soaking of the graft); and in group 3 (n=5), MMF (40 mg/kg) was administered orally. The animals were followed weekly with weight controls and signs of toxicity for 30 (n=37) and 60 (n=17) days, respectively. All animals were sacrificed and underwent histological examination at completion of the study. RESULTS All animals survived in groups 1 and 3, but five died in group 2. The weight gain was normal in all groups, except for the subgroup 2a receiving high dose rapamycins orally. All rats in group 3 suffered from diarrhea, whereas animals receiving high dose rapamycins showed toxic signs (hair loss, wound healing problems). Histological examination showed a significant increase in intimal hyperplasia in group 1 (0.03+/-0.01 and 0.14+/-0.05 microm after 30 and 60 days, respectively; P<0.01). Rapamycins in either application or dosage had no significant effect on intimal hyperplasia. CONCLUSIONS Local or systemic administration of rapamycins has no effect on intimal hyperplasia in synthetic vascular grafts. In contrast, toxic signs with weight loss were observed in animals treated with high dose rapamycins, but not in those treated with MMF. Thus, in the rat model, immunosuppression with rapamycins or MMF cannot be recommended for the prevention of intimal hyperplasia in the synthetic vascular graft model.