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J P Janssen

Publications and source records attributed to J P Janssen.

At least 19 recordsLinked to original sources
PubMed2000

Chylothorax.

Chylothorax is defined as an accumulation of chyle in the pleural space caused by disruption of the thoracic duct or one of its major divisions. Chyle has a high content of triglycerides. The odorless fluid is turbid and milky due to the presence of fat containing particles, the chylomicrons. The etiology of chylothorax can be divided into four major categories: tumor, trauma, idiopathic and miscellaneous. Although chylothorax is uncommon, it is a serious and potentially hazardous disorder. Loss of chyle leads to metabolic disturbances, malnutrition and immunodeficiency. Treatment consists of treatment of the underlying disease, conservative treatment (medium chain triglyceride diet, parenteral nutrition) or surgical intervention. Appropriate timing of surgical intervention is essential. Since the ligation of the thoracic duct can be performed during thoracoscopy, this minimal interventional technique is the procedure of choice when conservative treatment fails.

Chylothorax↗
PubMed2000

Detection of areas with viable remnant tumor in postchemotherapy patients with Ewing's sarcoma by dynamic contrast-enhanced MRI using pharmacokinetic modeling.

An approach is presented for monitoring the effects of neoadjuvant chemotherapy in patients with Ewing's sarcoma using dynamic contrast-enhanced perfusion magnetic resonance (MR) images. For that purpose, we modify the three-compartment pharmacokinetic permeability model introduced by Tofts et al. (Magn Reson Med 1991;17:357-67) to a two-compartment model. Perfusion MR images acquired using an intravenous injection with Gadolinium (Gd-DTPA) are analyzed with this two-compartment pharmacokinetic model as well as the with an extended pharmacokinetic model that includes the (local) arrival time t(0) of the tracer as an endogenous (estimated) parameter. For each MR section, a wash-in parameter associated with each voxel is estimated twice by fitting each of the two pharmacokinetic models to the dynamic MR signal. A comparison of the two wash-in parametric images (global versus local arrival time) with matched histologic macroslices demonstrates a good correspondence between areas with viable remnant tumor and a high wash-in rate. This can be explained by the high number and permeability of the (leaking) capillaries in viable tumor tissue. The novel pharmacokinetic model based on a local arrival time of tracer results in the best fit of the wash-in rate, the most important factor discerning viable from nonviable tumor components. However, parameter estimates obtained with this model are also more sensitive to noise in the MR signal. The novel pharmacokinetic model resulted in a sensitivity between 0.22 and 0.60 and a specificity between 0.61 and 1. The model based on a global arrival time gave sensitivities between 0.33 and 0.77 and specificities between 0.58 and 0.99. Both statistics are computed as the fraction of correctly labeled voxels (viable or nonviable tumor) within a specified ROI, which delineates the tumor. We conclude that the added value of estimating the local arrival time of tracer first manifests itself for moderate noise levels in the MR signal. The novel pharmacokinetic model should moreover be preferred when pharmacokinetic modeling is applied on the average signal intensity within a ROI, where noise has less effect on the fitted parameters.

Adolescent↗
PubMed1996

Pulmonary function of patients with spontaneous pneumothorax in relation to the extent of emphysema-like changes.

The aim of the present study was to analyse pulmonary function parameters of patients with spontaneous pneumothorax (SP) in relation to the extent of emphysema-like changes (ELCs). Pulmonary function tests were performed in 85 patients with unilateral SP, 6 weeks after video-assisted thoracoscopy (VAT). In 63 patients, thoracic computer tomography (CT) was obtained. An ELCs score, based on findings of CT and VAT, was used to quantify ELCs, ranging from 0 (expressing no ELCs) to 3 (expressing extensive ELCs). Emphysema-like changes were detected during VAT in 74% of patients, of which 70% were considered larger than 2 cm. An ELCs score > or = 2 was found in 27 patients. Clinical characteristics of the patients grouped according to thoracoscopical findings and ELCs score did not differ, except for age. Patients with large ELCs were significantly older than patients without ELCs or small ELCs (P = 0.0009). In patients with large ELCs and ELCs score > or = 2, increased mean percentages of predicted total lung capacity and decreased diffusing capacity (KCO) were found. None of the patients exhibited all pulmonary function criteria of emphysema, in contrast to 43% of the patients with an ELCs score > or = 2. KCO was the only pulmonary function parameter which was decreased in smokers, especially in patients with large ELCs or ELCs score > or = 2. Static lung compliance (Cstat) was the only pulmonary function parameter which was increased in patients with recurrent SP. The authors concluded that KCO is related to smoking behaviour and ELCs in patients with SP. Cstat is the only parameter which is increased in patients with recurrent SP. The discrepancy between pulmonary function and macroscopical parenchymal changes could be explained by the fact that not all patients with SP are old enough at presentation to show all signs of emphysema with pulmonary function testing. On the other hand, it might be possible that ELCs in SP cause different pulmonary function abnormalities than in centriacinar or panacinar emphysema.

Adult↗
PubMed1995

The value of parasternal mediastinoscopy in staging bronchial carcinoma.

Computed tomography (CT) is the non-invasive staging procedure of choice for assessment of metastasis to mediastinal lymph nodes in patients with bronchial carcinoma. Cervical mediastinoscopy can provide histologic evidence of mediastinal spread to the peritracheal, tracheobronchial and subcarinal lymph nodes. Sub-aortic and para-aortic nodes cannot be sampled via this route. The present study was performed to assess the staging value of the parasternal mediastinoscopy as a separate entity. Cervical and parasternal mediastinoscopy was performed in 37 patients with a proven diagnosis of non-small cell carcinoma of the left upper lobe. In 16 patients lymph node or tumor tissue could be biopsied via the parasternal route, in 21 patients no parasternal biopsy was taken. Of the 16 cases with biopsies, only one was positive (6%). Histologic examination of lymph node biopsy tissue was false negative in one other patient (6%). Of the 21 patients without biopsies taken during parasternal mediastinoscopy, three (14%) had proven lymphogenic spread to the subaortic and para-aortic nodes, detected at thoracotomy. The parasternal procedure changed treatment in only one patient (3%). Diagnostic sensitivity was 20%. It is concluded that parasternal mediastinoscopy should not be used as a routine staging procedure in patients with left upper lobe lung cancer.

Adenocarcinoma↗
PubMed1995

Videothoracoscopic appearance of first and recurrent pneumothorax.

STUDY OBJECTIVE: Comparison of the videothoracoscopic appearance of first and recurrent pneumothorax, and assessment of a relation between endoscopic appearance and recurrence rate. SETTING: University hospital. PATIENTS: Eighty-two patients, 64 men (mean age, 32.7 years) and 18 women (mean age, 31.5 years), were included. Patients with known underlying pulmonary disease at the time of hospital admission were excluded. There were 61 patients (74%) with first pneumothorax, and 21 patients (26%) with recurrent pneumothorax. INTERVENTIONS: All patients underwent videothoracoscopy under general anesthesia, with double-lumen intubation. RESULTS: Blebs or bullae were found in 47 patients (77%) with first pneumothorax, and in 14 patients (67%) with recurrent pneumothorax. Bullae > 2 cm were found in 34 patients (56%) with first pneumothorax and 10 patients (48%) with recurrent pneumothorax. Patients with blebs or bullae were significantly older than patients with normal videothoracoscopic appearance (mean age, 36.5 +/- 15.7 years vs 25.3 +/- 5.8 years, p < 0.05). Adhesions were significantly more frequently found in patients with blebs or bullae compared with patients with normal thoracoscopic appearance of the lung (p < 0.05). Seventeen of 21 patients (81%) with normal thoracoscopic appearance were smokers. Of nonsmoking patients (n = 22), 82% had blebs and bullae. CONCLUSIONS: No significant differences in videothoracoscopic appearance were found between first and recurrent pneumothorax. These results suggest that recurrence after the first event of spontaneous pneumothorax cannot be predicted by thoracoscopic findings. Smoking and blebs or bullae are independent risk factors for development of spontaneous pneumothorax.

Adolescent↗
PubMed1994

[Treatment of spontaneous pneumothorax: survey among Dutch pneumonologists].

OBJECTIVE: To gain insight into the treatment of spontaneous pneumothorax in the Netherlands. DESIGN: Questionnaire. SETTING: Nationwide in the Netherlands. METHOD: A questionnaire was sent to all 286 practising pulmonologists in the Netherlands to inquire about the mode of treatment used for spontaneous pneumothorax. Answers were sorted by size of practice. University hospital, non-university hospitals qualified for residency training and offices with at least 4 pulmonologists were classified as large practices. Other practices were classified as small. RESULTS: 89% of all pulmonologists responded. In small practices, a first spontaneous pneumothorax was treated by chest tube drainage; in large practices, thoracoscopy was usually performed. In recurrent pneumothorax, thoracoscopy was the first choice in both small and large practices. The role of interventional thoracoscopy and surgery was not established. CONCLUSION: Worldwide, including in the Netherlands, there is no consensus about the treatment of spontaneous pneumothorax. Randomised studies with cost-effect analysis are necessary.

Chest Tubes↗
PubMed1994

Primary sarcoma of the lung: a clinical study with long-term follow-up.

Primary pulmonary sarcoma is an extremely rare tumor. In more than 30 years, only 22 patients with PPS were seen in our hospital; 18 patients (82%) underwent operation. Radical resection is the only curative treatment in patients with primary pulmonary sarcoma. All 4 patients (18%) who did not undergo operation died within 17 months. All 7 patients (32%) in whom no radical resection could be performed died between 10 months and 16 years after operation. Total resection of the tumor could be performed in 11 patients (50%). Of these, 7 are still alive (64%), and 1 patient died of an unrelated cause after 25 years (mean follow-up, 13.5 years). Histologic diagnosis in these patients was leiomyosarcoma in 4, malignant schwannoma in 2, and fibrosarcoma and undifferentiated sarcoma in 1 each. Median survival for all patients was 24 months. Actuarial 5-year survival was 44% for all patients. Small tumor diameter and low-grade malignancy are statistically significant favorable prognostic factors. No patient with grade 1 tumor died; the median survival was 60 months for grade 2 sarcomas, and 17 months for grade 3 sarcomas. No patient with a completely resected small primary pulmonary sarcoma had recurrence or metastasis.

Adolescent↗
PubMed1994

Treatment of patients with spontaneous pneumothorax during videothoracoscopy.

Thoracoscopy for spontaneous pneumothorax has been performed over the years by many pulmonologists. The aim of the procedure was merely diagnostic: the detection of blebs and bullae. Therapeutic modalities were restricted to chemical pleurodesis. The development of videothoracoscopy has made more complex interventions, such as bullectomy possible. A protocol for videothoracoscopic treatment of spontaneous pneumothorax, with all treatment modalities in one session, has been developed. All patients with spontaneous pneumothorax underwent videothoracoscopy under general anaesthesia with double lumen tube intubation. If no abnormalities were found on the visceral pleura, talc pleurodesis was performed. Small lesions, blebs or bullae < 2 cm, were coagulated prior to pleurodesis. In case of blebs or bullae > 2 cm, thoracoscopic resection with an EndoGIA stapling device was performed, followed by scarification, i.e. electrocoagulation, of the parietal pleura. In 43 patients, 44 procedures were performed. In 15 cases (34%) no blebs or bullae were found. In 6 cases (14%) only blebs < 2 cm were found. In 23 cases (52%) blebs and bullae > 2 cm were found. In 21 out of 44 cases (48%), talc pleurodesis was performed, and in 23 cases (52%) bullectomy was performed. No major complication occurred. The average hospital stay was 5.7 days after talc pleurodesis and 6.0 days after bullectomy. There were 2 recurrences (5%) after a follow-up of at least 18 months. In conclusion, the use of videothoracoscopy in spontaneous pneumothorax makes it possible to continue a diagnostic procedure as a therapeutic session.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Endoscopic management of bronchial stenosis after double lung transplantation.

Double lung transplantation with bilateral bronchial sutures is an increasingly popular therapeutic alternative for endstage, bilateral, septic pulmonary disease; however, surgical outcome has been hampered by mechanical complications at the level of the airway anastomoses. In our institution, therefore, the protocol for surveillance includes frequent flexible fiberoptic and rigid bronchoscopy under general anesthesia in all patients. Since 1988, there were 24 double lung transplantations (mean age, 19 yr) performed at the University of Marseille Hospitals using bilateral sutures without omental wrapping. Nineteen patients had cystic fibrosis; of the ten individuals (53 percent) with cystic fibrosis who ultimately developed bronchial stenosis, six required therapeutic endoscopic intervention including dilatation or Nd:YAG laser resection. Five patients required endobronchial silicone stents. Statistically significant risk factors for postsurgical airway narrowing included young age (mean, 14.3 yr vs 24.0 yr in patients without stenosis) and prolonged mechanical ventilation prior to transplant (all five patients ventilated before surgery developed stenosis). Results of interventional bronchoscopy were good, and an excellent level of physical activity was maintained in most patients. A team familiar with all aspects of therapeutic bronchoscopy is essential to ensure proper management of airway complications in patients after lung transplantation.

Adolescent↗
PubMed1992

Extended thoracoscopy: a biopsy method to be used in case of pleural adhesions.

Extended thoracoscopy (ET) allows several large biopsies to be taken in patients with thick adhesions of the pleura when normal thoracoscopy is impossible. Twenty patients with undiagnosed pleural effusion or thickening and two with associated pulmonary tumour close to the chest wall underwent ET because closed adhesions prevented the induction of an artificial pneumothorax. Under local anaesthesia and neuroleptanalgesia, at the site of suspected lesions on computed tomographic (CT) scan, a cutaneous incision of 3-4 cm is made on the appropriate intercostal space. After dissection with blunt scissors, the operator introduces his finger to create a space in the pleural cavity. The thoracoscope is inserted to inspect the pleura and to take several biopsies for histopathological examination. A chest tube is inserted for a few minutes after checking airtightness and haemostasis. The procedure is well-tolerated. In three cases no pleural biopsy could be taken; in three patients a false negative diagnosis was observed. A correct diagnosis was obtained in 16 out of 19 patients (84%). If performed by a pulmonologist experienced with thoracoscopy ET is a rapid, safe and efficient method to obtain biopsies in cases where normal thoracoscopy after induction of a pneumothorax is not possible. It considerably reduces the need for open thoracotomy.

Adolescent↗
PubMed1990

[localized fibrous tumors of the pleura].

The localized fibrous tumour of the pleura, also named localized fibrous mesothelioma or fibroma of the pleura, is a very rare tumour with a benign behaviour. Its origin, clinical behaviour and prognosis are very different from malign mesothelioma. In a 33-year period 22 patients with this diagnosis were surgically treated. The prognosis was excellent. In this article the clinical and radiological signs, as well as the diagnosis and therapy are discussed.

Adult↗