Complications in CT-Guided, Semi-Automatic Coaxial Core Biopsy of Potentially Malignant Pulmonary Lesions.

PURPOSE: Histological verification of pulmonary lesions is important to ensure correct treatment. Computed tomographic (CT) transthoracic core biopsy is a well-established procedure for this. Comparison of available studies is difficult though, as technical and patient characteristics vary. Using a standardized biopsy technique, we evaluated our results for CT-guided coaxial core biopsy in a semi-automatic technique. MATERIALS AND METHODS: Within 2 years, 664 consecutive transpulmonary biopsies were analyzed retrospectively. All interventions were performed using a 17/18G semi-automatic core biopsy system (4 to 8 specimens). The incidence of complications and technical and patient-dependent risk factors were evaluated. RESULTS: Comparing the histology with the final diagnosis, the sensitivity was 96.3%, and the specificity was 100%. 24 procedures were not diagnostic. In all others immunohistological staining was possible. The main complication was pneumothorax (PT, 21.7%), with chest tube insertion in 6% of the procedures (n = 40). Bleeding without therapeutic consequences was seen in 43 patients. There was no patient mortality. The rate of PT with chest tube insertion was 9.6% in emphysema patients and 2.8% without emphysema (p = 0.001). Smokers with emphysema had a 5 times higher risk of developing PT (p = 0.001). Correlation of tumor size or biopsy angle and the risk of PT was not significant. The risk of developing a PT was associated with an increasing intrapulmonary depth of the lesion (p = 0.001). CONCLUSION: CT-guided, semiautomatic coaxial core biopsy of the lung is a safe diagnostic procedure. The rate of major complications is low, and the sensitivity and specificity of the procedure are high. Smokers with emphysema are at a significantly higher risk of developing pneumothorax and should be monitored accordingly. KEY POINTS: Using an 18G core biopsy system with 6 specimens will allow immunohistological staining with high sensitivity and specificity. Smokers with emphysema are at a significantly higher risk of developing a pneumothorax.

Development of proteinuria after switch to sirolimus-based immunosuppression in long-term cardiac transplant patients.

Calcineurin-inhibitor therapy can lead to renal dysfunction in heart transplantation patients. The novel immunosuppressive (IS) drug sirolmus (Srl) lacks nephrotoxic effects; however, proteinuria associated with Srl has been reported following renal transplantation. In cardiac transplantation, the incidence of proteinuria associated with Srl is unknown. In this study, long-term cardiac transplant patients were switched from cyclosporine to Srl-based IS. Concomitant IS consisted of mycophenolate mofetil +/- steroids. Proteinuria increased significantly from a median of 0.13 g/day (range 0-5.7) preswitch to 0.23 g/day (0-9.88) at 24 months postswitch (p = 0.0024). Before the switch, 11.5% of patients had high-grade proteinuria (>1.0 g/day); this increased to 22.9% postswitch (p = 0.006). ACE inhibitor and angiotensin-releasing blocker (ARB) therapy reduced proteinuria development. Patients without proteinuria had increased renal function (median 42.5 vs. 64.1, p = 0.25), whereas patients who developed high-grade proteinuria showed decreased renal function at the end of follow-up (median 39.6 vs. 29.2, p = 0.125). Thus, proteinuria may develop in cardiac transplant patients after switch to Srl, which may have an adverse effect on renal function in these patients. Srl should be used with ACEi/ARB therapy and patients monitored for proteinuria and increased renal dysfunction.

Comparison of different decellularization procedures of porcine heart valves.

BACKGROUND: Tissue engineering of heart valves should avoid the disadvantages of conventional prostheses. In this study we tested different decellularization procedures for their potential of cell removal and their ability to preserve the matrix. METHODS: Specimens of porcine aortic and pulmonary roots were treated with either trypsin or sodium-dodecyl-sulfate (SDS) or Triton-X 100 and sodium-deoxycholate with a range of concentrations. Tissue samples were then processed for scanning electron microscopy and laser scanning microscopy. RESULTS: Trypsin achieved only incomplete decellularization and caused severe structural alterations of the matrix. In contrast SDS removed cells completely but caused strong structural alterations. Treatment with Triton-X100 and sodium-deoxycholate achieved both complete decellularization and preservation of the matrix structure. CONCLUSION: Techniques of decellularization are highly variable in efficiency and matrix preservation and was best achieved in our study with Triton-X100 and sodium deoxycholate.

Early failure of the tissue engineered porcine heart valve SYNERGRAFT in pediatric patients.

OBJECTIVES: The first tissue engineered decellularized porcine heart valve, Synergraft (Cryolife Inc., USA) was introduced in Europe as an alternative to conventional biological valves. This is the first report of the rapid failure of these new grafts in a small series. MATERIALS AND METHODS: In 2001, 2 model 500 and 2 model 700 Synergraft valves were implanted in four male children (age 2.5-11 years) in the right ventricular outflow tract as a root. Two patients had a Ross operation and two had a homograft replacement. RESULTS: The cryopreserved Synergraft valves appeared macroscopically unremarkable at implantation. Recovery from surgery was uneventful and good valve function was demonstrated postoperatively. Three children died, two suddenly with severely degenerated Synergraft valves 6 weeks and 1 year after implantation. The third child died on the 7th day due to Synergraft rupture. Subsequently the fourth graft was explanted prophylactically 2 days after implantation. Macroscopically all four grafts showed severe inflammation starting on the outside (day 2 explant) leading to structural failure (day 7 explant) and severe degeneration of the leaflets and wall (6 weeks and 1 year explant). Histology demonstrated severe foreign body type reaction dominated by neutrophil granulocytes and macrophages in the early explants and a lymphocytic reaction at 1 year. In addition significant calcific deposits were demonstrated at all stages. Surprisingly pre-implant samples of the Synergraft revealed incomplete decellularization and calcific deposits. No cell repopulation of the porcine matrix occurred. CONCLUSION: The xenogenic collagen matrix of the Synergraft valve elicits a strong inflammatory response in humans which is non-specific early on and is followed by a lymphocyte response. Structural failure or rapid degeneration of the graft occurred within 1 year. Calcific deposits before implantation and incomplete decellularization may indicate manufacturing problems. The porcine Synergraft treated heart valves should not be implanted at this stage and has been stopped.

Single running suture--the new standard technique for bronchial anastomoses in lung transplantation.

OBJECTIVE: The aim of this retrospective study is to assess the results of a single running suture technique for bronchial anastomoses in lung transplantation. In a previous pilot study, equal results compared to the established standard technique --using single stitches on the cartilaginous part--have been described by our group. This report reviews the results obtained over a period of 3 years. METHODS: Between January 1999 and December 2001, 154 consecutive lung transplantations (91 bilateral sequential, 35 right single lung and 28 left single lung) were performed in 141 patients using single running sutures for bronchial anastomoses. Thirteen transplantations (25 anastomoses) were performed in lobar or split lung technique. Bronchial healing was assessed at routine bronchoscopes performed in increasing time intervals from 7 days to 1 year postoperatively and depending upon clinical necessity. RESULTS: Six patients (4.2%) died earlier than 7 days postoperatively and were excluded from further analysis. No bronchial complication was observed in any of them. Three months and 1-year survival rates were 82.9 and 72.7%, respectively. Two hundred and thirty-four anastomoses were subjected to examination. Mean ischemic time was 5.1h (+/-1.5). In 228 anastomoses (97.4%), excellent primary airway healing was observed. In four anastomoses (1.7%), small healing defects less than 5mm without necessity for intervention were detected. Two anastomoses (0.9%) developed a cicatriceal stenosis requiring intraluminal stenting. CONCLUSIONS: The single running suture technique for bronchial anastomoses in lung transplantation provides excellent results with regard to primary and long-term airway healing and its use as a standard suturing technique is, therefore, recommended.

First experiences with outpatient care of patients with implanted axial flow pumps.

As known from patients with pulsatile ventricular assist devices (VADs), early mobilization, physical exercise, and return to normal life are essential for optimal recovery. Recently, implantable rotary pumps became available for extended left ventricular support as bridges to transplantation. Modified procedures are essential for patient training and hospital discharge. The MicroMed-DeBakey VAD was implanted in 10 patients with end-stage heart disease. After recovery, regular ergometer training was performed with loads adapted to the patient's condition. Procedures for patient observation under outdoor conditions and a blood pressure measuring device for low pulse pressure conditions were developed. Improvement of physical condition was achieved in 8 patients. In the first 2 patients, exercise capacity was limited due to flow obstruction. In the following patients, an increase of workload on the ergometer up to 120 W was observed. Correlated with training, lactate/load relationship and heart rate decreased. Three patients were discharged from the hospital during support. The DeBakey-VAD system can support patients for extended time periods and is suitable for recovery and exercise. Under optimal patient and environmental conditions, discharge from the hospital can be obtained.

Adhesion molecule behavior during rejection and infection episodes after heart transplantation.

In cardiac transplant recipients the release of soluble cellular adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-Selectin into serum is pronounced during immune activation. It is uncertain whether there is a specific pattern of release during infection or cardiac allograft rejection. In a prospective study, 30 consecutive cardiac allograft recipients were followed for a median period of 11.4 months (range 1-34). Soluble ICAM-1 (sICAM-1), soluble VCAM-1 (sVCAM-1) and soluble E-Selectin (sE-Selectin) were measured in addition to acute phase proteins (C-reactive protein, alpha1-antitrypsin), complement factors (C3, C4) and beta2-microglobulin. The measured serum levels were correlated with the clinical status of the transplant recipient: 1) uneventful clinical status; 2) asymptomatic infection; 3) symptomatic infection and 4) rejection. Forty age-matched healthy subjects served as controls. Six days before biopsy-proven cardiac allograft rejection sICAM-1-release started to increase (p < 0.05) as compared to uneventful clinical status. The peak concentration of sICAM-1 was measured three days before rejection. On the day of rejection, serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were increased, whereas sE-Selectin was not markedly elevated. In symptomatic infections, the serum concentrations of sICAM-1 (p < 0.001) and sVCAM-1 (p < 0.05) were elevated at the day of diagnosis and both parameters reached peak levels three days after onset of chemotherapy. In multivariate analysis soluble adhesion molecules only weakly discriminated between rejection and infection (sensitivity: 13%, specificity: 95%). Although, in combination with routine blood parameters the discriminatory power could be improved (sensitivity: 85%, specificity: 85%) the clinical utility of these markers in non-invasive monitoring is limited.

Evaluation of the EMIT Mycophenolic Acid Assay from Dade Behring.

The Emit Mycophenolic Acid Assay, a new homogeneous enzyme immunoassay for the quantitative analysis of mycophenolic acid (MPA) in human plasma, was evaluated and compared to a high-performance liquid chromatography (HPLC) method. Coefficients of variation (CV) of the within-run imprecision (n = 10) varied from 2.5% to 4.4% and from 1.3% to 4.9% for the Emit and the HPLC, respectively. The CV's of between-day imprecision (n = 10) ranged from 7.9% to 10.8% for the Emit and from 4.7% to 12.1% for the HPLC. Mean recoveries were 95.6% and 100.1% for Emit and HPLC, respectively. Serial dilution of a patient pool demonstrated a linear relationship between expected (x) and measured (y) concentrations: Emit, y = 0.998x + 0.086; HPLC, y = 1.006x - 0.016. The detection limit and the lower limit of quantification were 0.087 mg/L and 0.20 mg/L for Emit. The detection limit for HPLC was 0.08 mg/L using a signal-to-noise ratio of three. Sample stability under various storage conditions was satisfactory, although storage at -20 degrees C is recommended for storage longer than one day. No cross-reactivity from the major metabolite mycophenolic acid glucuronide (MPAG) was found. A correlation study on 261 patient samples yielded the following regression equation (bivariate Deming procedure): Emit = 1.012HPLC + 0.244, r = 0.970.

A simple HPLC method for monitoring mycophenolic acid and its glucuronidated metabolite in transplant recipients.

Mycophenolic acid (MPA) is nowadays in broad clinical use as a substitute for azathioprine. An immunoassay for MPA recently received approval for clinical applications. The high performance liquid chromatography (HPLC) assay for measuring MPA and its glucuronide conjugate (MPAG) we describe here is not only rapid and simple but also extremely sensitive at plasma levels obtained during standard immunosuppressive regimens. The determination of MPAG is possible without any change of the chromatographic conditions (detection wavelength of 214 nm, mobile phase: acetonitrile and 50 mmol/l o-phosphoric acid (50:50, V/V), run time: 15 min). The required equipment is a standard HPLC system including a simple UV-detector. Sample volume of 400 microl is required for both determinations. Detection limit is 0.25 micromol/l for MPA and 5 micromol/l for MPAG. Linearity is excellent for serial dilutions (0.5-25 micromol/l for MPA, 25-500 micromol/l for MPAG) and high accuracies favour the method described. More than 2000 plasma samples tested for MPA in patients after heart transplantation within one year and more than 500 samples for MPAG underline the clinical applicability of this assay.

IMP-dehydrogenase inhibition in human lymphocytes and lymphoblasts by mycophenolic acid and mycophenolic acid glucuronide.

Inosine 5'-monophosphate dehydrogenase (IMP-DH) activities were measured in human lymphocytes (exhibiting type I IMP-DH activity) and human lymphoblasts (exhibiting type II IMP-DH activity) in the presence of various amounts of mycophenolic acid (MPA) (0-20 mumol/L) and MPA glucuronide (MPAG) (0-200 mumol/L). Moreover, the influences of human serum albumin (HSA) and human plasma on the MPA- and MPAG-mediated effects were investigated. In the presence of water, 2.5 mumol/L MPA decreased the IMP-DH activity measured in lymphocytes by 60%, whereas in lymphoblasts a 80% inhibition was detectable. In the presence of > or = 10 mumol/L MPA, lymphocytic as well as lymphoblastic IMP-DH activities were reduced in a similar manner. The concentration of MPAG required for 50% inhibition was for both cell types > 25 mumol/L and < 50 mumol/L, respectively. MPAG (200 mumol/L) reduced lymphocytic as well as lymphoblastic IMP-DH activity by approximately 80%. With 100 g/L HSA or human plasma as diluent, the inhibitory effects of MPA and MPAG were significantly (P < 0.05) diminished, whereas HSA concentrations < or = 25 g/L only slightly influenced the inhibition of IMP-DH activity by MPA and MPAG. In summary, it can be clearly demonstrated that not only MPA but also MPAG contributes to the inhibition of both IMP-DH isoenzymes, which might be relevant for the immunosuppressive properties of mycophenolate mofetil in transplant patients.

Saccharomyces cerevisiae alpha-factor prevents formation of glycoproteins in a cells.

alpha-Factor inhibits incorporation of [14C]glucosamine into water-soluble and into SDS-extractable glycoproteins to about 90%. The incorporation into chitin is not affected and the same is true for [14C]phenylalanine incorporation into protein. The inhibition of glycoprotein synthesis is specific for a cells.