Bacterial biofilm in chronic lesions of hidradenitis suppurativa

BACKGROUND

Chronic nonhealing or recurrent inflammatory lesions, reminiscent of infection but recalcitrant to antibiotic therapy, generally characterize biofilm-driven diseases. Chronic lesions of hidradenitis suppurativa (HS) exhibit several characteristics, which are compatible with well-known biofilm infections.

OBJECTIVES

To determine and quantify the potential presence of bacterial aggregates in chronic HS lesions.

METHODS

In 42 consecutive patients with HS suffering from chronic lesions, biopsies were obtained from lesional as well as from perilesional skin. Samples were investigated using peptide nucleic acid-fluorescence in situ hybridization in combination with confocal laser scanning microscopy. In addition, corresponding histopathological analysis on haematoxylin and eosin slides was performed.

RESULTS

Biofilms were seen in 67% of the samples of chronic lesions and in 75% of the perilesional samples. The mean diameter of aggregates in lesional skin was significantly greater than in perilesional skin (P = 0·01). Large biofilms (aggregates > 50 μm in diameter) were found in 42% of lesional samples and in only 5% of the perilesional samples (P = 0·009). The majority of the large biofilms were situated in sinus tracts (63%) or in the infundibulum (37%). The majority of the sinus tract samples (73%) contained active bacterial cells, which were associated with inflammation.

CONCLUSIONS

This study suggests that biofilm formation is associated with inflammation of chronic HS lesions. The aggregates most likely occur as a secondary event, possibly due to predisposing local anatomical changes such as sinus tracts (tunnels), keratinous detritus and dilated hair follicles.

Optical coherence tomography in optic neuritis and multiple sclerosis: a review

Optical coherence tomography (OCT) is a new noninvasive high-resolution method that measures the retinal nerve fiber layer (RNFL) thickness. An overview of the use in optic neuritis (ON) and multiple sclerosis (MS) is presented. Literature survey of PubMed was carried out. RNFL thickness in eyes of healthy control subjects was 102.9-111.11 microm, in eyes affected by ON 59.79-85 microm, and in fellow eyes 82.73-99.8 microm. All studies found a significant reduction in RNFL in eyes affected by ON compared with fellow eyes and eyes of healthy controls. Two out of three studies found a significant reduction in RNFL in fellow eyes compared with control eyes. RNFL thickness correlated with visual acuity, visual field, low-contrast letter acuity, contrast sensitivity, and color vision. Correlations were also found with the optic nerve area evaluated by magnetic resonance imaging, neurologic impairment score, and increasing disease duration. One of two studies found a significant correlation with amplitudes of visual evoked potentials, neither correlated with latencies. OCT is a promising new tool for evaluating atrophy in patients with ON and MS.

Inhibition of endothelial cell migration by gene transfer of tissue inhibitor of metalloproteinases-1

BACKGROUND

Angiogenesis requires degradation of the vessel's basal lamina and endothelial cell migration into the tissue stroma. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play important roles in this process. MMP activity is tightly regulated during vessel growth. This work was designed to characterize the effect of TIMP-1 upregulation on endothelial cell invasion of the extracellular matrix.

METHODS

We constructed replication-deficient recombinant adenoviruses that encode either TIMP-1 (Ad.TIMP-1) or Escherichia coli lac Z (Ad.beta gal) cDNA. Bovine aortic endothelial (BAE) cells were infected with 100 infectious particles/cell. Gene expression was assessed by Northern and Western blotting. TIMP-1 activity in cell-conditioned media was measured by a resorufin-labeled casein protease assay. BAE cell migration was measured by Boyden chamber assays with 0.2% gelatin-coated, 8. 0-mcm polycarbonate membranes.

RESULTS

TIMP-1 was overexpressed by Ad.TIMP-1-infected BAE cells relative to control, Ad. beta gal-infected or uninfected cells. TIMP-1 activity in Ad.TIMP-1 cell-conditioned medium was 2.8-fold higher than in control cells. By Boyden chamber assays with gelatin-coated membranes, Ad. TIMP-1-infected BAE cells showed 89.97 +/-1.64% (mean +/- SEM) reduction in migration relative to Ad.beta gal-infected cells (P < 0. 02) and 90.53 +/- 1.12% relative to uninfected cells (P < 0.02). Without gelatin coating, migration was equivalent in all groups.

CONCLUSION

The replication-deficient recombinant adenovirus we constructed affords rapid and efficient upregulation of functional TIMP-1 in endothelial cells. Infection results in a dramatic decrease in cell migration and invasion of extracellular matrix. Thus, such a recombinant vector may provide a useful tool for the gene therapy of vascular remodeling and inhibition of angiogenesis.

Early results of posterior leaflet folding plasty for mitral valve reconstruction

BACKGROUND

Standard reconstruction for posterior mitral leaflet (PML) disease is quadrangular resection and annular plication; when the PML is excessively high, a sliding plasty is used. We have developed an alternative technique, a posterior leaflet folding plasty. It is performed by folding down the cut vertical edges of the PML. The central height of the PML is reduced, leaflet coaptation is moved posteriorly, and annular plication is unnecessary.

METHODS

From March 1995 to August 1996, 26 (17.9%) of 145 patients undergoing mitral reconstruction had a posterior leaflet folding plasty. Concomitant procedures included anterior leaflet resection or resuspension and myotomy and myectomy. In 3 patients, the PML resection extended to a commissure.

RESULTS

There was one death and no reoperations. The mean New York Heart Association class was improved from 2.4 preoperatively to 1.4. There was no major postoperative mitral insufficiency in the 26 patients. Systolic anterior motion was transiently seen in 1 patient in whom left ventricular outflow tract obstruction was present preoperatively.

CONCLUSIONS

The data demonstrate the safety and short-term efficacy of posterior leaflet folding plasty. This technique may help avoid systolic anterior motion after reconstruction of the PML.

Acellularized porcine heart valve scaffolds for heart valve tissue engineering and the risk of cross-species transmission of porcine endogenous retrovirus

OBJECTIVE

Acellularized porcine heart valve scaffolds have been successfully used for heart valve tissue engineering, creating living functioning heart valve tissue. However, there is concern about the possibility of porcine endogenous retrovirus transmission. In this study we investigated whether acellularized porcine heart valve scaffold causes cross-species transmission of porcine endogenous retrovirus in a sheep model.

METHODS

Acellularized porcine pulmonary valve conduits (n = 3) and in vitro autologous repopulated porcine pulmonary valve conduits (n = 5) were implanted into sheep in the pulmonary valve position. Surgery was carried out with cardiopulmonary bypass support. The animals were killed 6 months after the operation. Blood samples were collected regularly up to 6 months after the operation and tested for porcine endogenous retrovirus by means of polymerase chain reaction and reverse transcriptase-polymerase chain reaction. In addition, explanted tissue-engineered heart valves were tested for porcine endogenous retrovirus after 6 month in vivo.

RESULTS

Porcine endogenous retrovirus DNA was detectable in acellularized porcine heart valve tissue. However, 6 months after implantation of in vitro and in vivo repopulated acellularized porcine heart valve scaffolds, no porcine endogenous retrovirus sequences were detectable in heart valve tissue and peripheral blood.

CONCLUSION

Acellularized porcine matrix scaffolds used for creation of tissue-engineered heart valves do not transmit porcine endogenous retrovirus.

Impact of heparin bonding on pediatric cardiopulmonary bypass: a prospective randomized study

BACKGROUND

Heparin-coated circuits reduce the inflammatory response to cardiopulmonary bypass in adult patients; however, little is known about its effects in the pediatric population. Two studies were performed to assess this technology's impact on inflammation and clinical outcomes.

METHODS

In a pilot study, complement and interleukins were measured in 19 patients who had either uncoated cardiopulmonary bypass circuits or heparin-bonded circuits. Subsequently, 23 additional patients were studied in a randomized fashion. Respiratory function and blood product utilization were recorded.

RESULTS

In the pilot study, heparin-bonded circuit patients had less complement 3a (p < 0.001) and interleukin-8 (p < 0.05) compared with uncoated cardiopulmonary bypass circuit patients. The randomized study revealed that the heparin-bonded circuit was associated with reduced complement 3a (p = 0.02). Multiple variable analysis revealed that the following postoperative variables were increased with bypass time (p = 0.01) and diminished with heparin-bonded circuits: interleukins (p = 0.01), peak airway pressures (p = 0.05), and prothrombin time (p = 0.03).

CONCLUSIONS

Heparin-bonded circuits significantly reduce cytokines and complement during cardiopulmonary bypass and lower interleukin levels postbypass; they were also associated with improved pulmonary and coagulation function. Heparin-bonded circuits ameliorate the systemic inflammatory response in pediatric patients from cardiopulmonary bypass.

Valve sparing aortic root reconstruction versus composite replacement -- perioperative course and early complications

OBJECTIVE

In patients with aneurysm of the ascending aorta, dilatation of the sinotubular junction is the major cause of aortic valve regurgitation. Valve sparing aortic root replacement in patients without valvular structural defects offers a new form of treatment. The aim of this study was the assessment of the perioperative course and early complications of this method compared to composite replacement in a large single center cohort.

METHODS

From 1992 to 1999, valve sparing replacement of the ascending aorta (recon) has been performed in 78 patients, while 269 patients underwent replacement by a composite graft (comp). A comparison of matched pairs (n=52) with respect to age, gender, presence of Marfan's syndrome, aortic dissection as well as date of surgery, was chosen. Aortic insufficiency was 2.8+/-0.7 for recon vs. 2.2+/-1.1 for comp preoperatively. Course and length of hospitalization, echocardiographic follow-up, complications, and mortality were compared at 1-year follow-up.

RESULTS

There were no operative deaths. During follow-up, one patient (2%) died 5 months postoperatively (recon) vs. two patients (3.9%) in the comp group. Bypass-time (123+/-31 vs. 153+/-31 min, P<0.0001) and cross-clamp-time (82+/-22 vs. 120+/-23 min, P<0.0001) were significantly shorter in comp. Stay in ICU (1.9+/-1.6 for recon vs. 2.3+/-2.1 days for comp) and post-op hospitalization (18.3+/-5.7 vs. 21.2+/-11.1 days) were comparable. Improvement of NYHA-class was significant after both operations (recon 2.6+/-0.8 vs. 1.3+/-0.5 and for comp 2.4+/-0.6 vs. 1.5+/-0.7, both P<0.0001). One patient (1.9%) in the recon group had to be reoperated for valve failure. Thrombembolic or bleeding complications were observed in 6 patients (12%) in comp, zero in recon (P=0.027).

CONCLUSION

Valve sparing aortic root reconstruction is feasible with low perioperative morbidity and mortality and good early results. Major advantages of recon are significant reduction of thrombembolic and anticoagulation related complications as opposed to longer cross-clamp and bypass times as well as a valve failure in one patient. Further follow-up is needed to confirm our data in a long-term perspective.

Marfan syndrome: A therapeutic challenge for long-term care

Marfan syndrome (MFS) is an autosomal dominant genetic disorder caused by mutations in the fibrillin-1 gene. Acute aortic dissection is the leading cause of death in patients suffering from MFS and consequence of medial degeneration and aneurysm formation. In addition to its structural function in the formation of elastic fibers, fibrillin has a major role in keeping maintaining transforming growth factor β (TGF-β) in an inactive form. Dysfunctional fibrillin increases TGF-β bioavailability and concentration in the extracellular matrix, leading to activation of proinflammatory transcription factors. In turn, these events cause increased expression of matrix metalloproteinases and cytokines that control the migration and infiltration of inflammatory cells into the aorta. Moreover, TGF-β causes accumulation of reactive oxygen species leading to further degradation of elastin fibers. All these processes result in medial elastolysis, which increases the risk of vascular complications. Although MFS is a hereditary disease, symptoms and traits are usually not noticeable at birth. During childhood or adolescence affected individuals present with severe tissue weaknesses, especially in the aorta, heart, eyes, and skeleton. Considering this, even young patients should avoid activities that exert additional stress and pressure on the aorta and the cardiovascular system. Thus, if the diagnosis is made and prophylactic treatment is initiated in a timely fashion, MFS and its preliminary pathophysiologic vascular remodeling can be successfully ameliorated reducing the risk of life-threatening complications. This commentary focuses on new research opportunities and molecular findings on MFS, discusses future challenges and possible long-term therapies.

Acute dissection of the ascending aorta: first results of emergency valve sparing aortic root reconstruction

OBJECTIVE

Acute dissection of the ascending aorta requires immediate surgical intervention. In this study, we report our first results with valve sparing aortic root reconstruction removing all the diseased tissues.

METHODS

From August 1995 to December 2000, 22 patients with acute aortic dissection of the ascending aorta (Stanford type A) underwent valve sparing aortic root reconstruction. Their ages ranged from 20 to 76 years (52+/-15, 68% males). Dissection was found in the ascending aorta (3 patients) or both in the ascending aorta and aortic arch (19 patients; 86%). Course and length of hospitalization, echocardiographic and clinical follow-up, complications and mortality were analysed.

RESULTS

Mean cardiopulmonary bypass time was 212+/-56 min (134-352 min), mean aortic cross clamp time was 157+/-24 min (114-205 min). In patients undergoing additional arch replacement (n=19), circulatory arrest was 35+/-18 min (11-75 min). After reconstruction, intraoperative echocardiography showed aortic insufficiency (AI) grade 0 in 16 patients (84%) and grade 1 in three patients (16%). Stay in intensive care unit was 2.1+/-0.7 days, and postoperative hospitalization was 21+/-14.4 days. There were three perioperative deaths (14%). Mean post-operative follow-up was 18.4+/-18 months (0.4-65.4 month). One patient died 10 months postoperatively. At follow-up, no patient suffered AI grade 2 or higher, and no reoperation for aortic valve failure was necessary. All patients presented with a favorable exercise tolerance being in New York Heart Association functional class I or II.

CONCLUSION

Valve sparing aortic root reconstruction in patients with type A dissection can be performed with acceptable intraoperative mortality and morbidity and excellent results during follow-up. The complete resection of the diseased aorta is particularly appealing.

Outcome Following Single vs Bilateral Lung Transplantation in Recipients 60 Years of Age and Older

AIMS

The significant shortage of donor organs in lung transplantation necessitates a careful selection of lung transplant recipients. The outcome of lung transplant recipients aged 60 years and older has not been analyzed systematically.

METHODS

We retrospectively reviewed our experience with older recipients. Between January 1999 and July 2003, 248 patients underwent lung transplantation at our institution, of which 18 were aged 60 years and older (7.3%, range 60-66, mean 62 +/- 1.1).

RESULTS

Eleven (61%) of the recipients 60 years and older received a single (SLTx) and seven (39%), a bilateral lung transplant. Donor age in the single transplant cohort was 30 +/- 4 years. It was 33 +/- 3 years in bilateral patients. Posttransplant ventilation time was significantly different among groups, with 282 +/- 32 hours after bilateral and 56 +/- 13 hours after transplant (P < .05). Also significantly longer was the length of the ICU stay in the bilateral group. First PaO2 in the ICU was not different among the two groups. The 1-year survival in the single transplant group was significantly better compared to the bilateral group with 73% versus 43%, respectively.

CONCLUSIONS

The 1-year survival following lung transplantation in patients older than 60 years is markedly reduced compared to recipients under 60 years of age. If a lung transplant is considered in a recipient above the age of 60 years, a single transplant should be favoured. If that is not indicated, patients over 60 should be very carefully selected for bilateral transplant.

Acute aortic dissection versus aortic root aneurysm: comparison of indications for valve sparing aortic root reconstruction☆

OBJECTIVES

To prove whether different indications for valve sparing aortic root reconstruction may have an impact on the outcome and longevity of the repair.

METHODS

From July 1993 to March 2003, the reimplantation technique for valve sparing aortic root reconstruction was applied to 232 patients. In 44 patients, indication for operation was acute aortic dissection type A (AADA). These patients were compared with 44 randomised patients operated for aortic root aneurysm (root) by matched pair analysis with respect to age, gender, time point of operation and presence of Marfan's syndrome. Peri- and post-operative courses with focus on survival and valvular stability were analysed.

RESULTS

Pre-operative grade of aortic insufficiency was 2.4+/-1 in root vs. 1.5+/-1.7 in AADA (P = 0.004) Mean CPB-time (214+/-60 vs. 171+/-42 min;P < 0.001), aortic cross clamp time (158+/-40 vs. 129+/-39 min; P = 0.001) and stay on ICU (5.2+/-9 vs. 1.7+/-1 days; P = 0.034) were longer for AADA, while hospitalisation was comparable (14+/-10 vs. 14+/-7 days; P = 0.88). Five patients (11.4%) from AADA died peri-operatively compared to no patient from root (P = 0.055). None of the early deaths were valve-related. Re-thoracotomy rate was 6.8% for both groups. Mean follow-up was 19+/-21 months for AADA vs. 28+/-21 months for root (P = 0.038) Survival at 3 years was 88+/-5% for AADA and 100% for root (P = 0.028). Freedom from valvular reoperation was 97+/-2.7% for root and 97+/-3% for AADA at 3 years (P = 0.44). At last investigation, mean grade of aortic insufficiency for AADA was 0.2+/-0.3 compared to 0.3+/-0.3 for root (P = 0.34)

CONCLUSIONS

Regardless of the underlying indication, the aortic valve preserving reimplantation technique can be performed with favourable functional results.

Impact of preoperative aortic root diameter on long-term aortic valve function after valve sparing aortic root reimplantation

BACKGROUND

Valve sparing aortic root reimplantation technique in patients with aortic root aneurysm have shown excellent mid-term results. In conjunction with the diameter of the aortic root the mechanical leaflet stress increase, which might have an impact on long-term aortic valve function after valve sparing aortic root reimplantation.

METHODS AND RESULTS

From July 1993 to October 2001, 168 patients with aortic root aneurysm underwent valve sparing aortic root reimplantation. Patients with type A aortic dissection were excluded. Thus, 123 patients were analyzed. We identified 47 patients with an preoperative aortic root diameter exceeding 60 mm (group A), 58 patients with an diameter between 50 and 60 mm (group B), and 18 patients with a diameter less than 50 mm (group C). The groups were compared regarding mortality, long-term survival, freedom from reoperation, freedom from severe and moderate aortic valve insufficiency (AI), and postoperative morbidity. Mean follow-up (group A 43+/-26 months, group B 40+/-25 months, group C 23+/-19 months; group C versus group A, P=0.005; group C versus group B, P=0.011) was shorter in group C. Perioperative mortality (group A 2.2%, group B 1.9%, group C 5.2%; P=ns) was comparable between the groups with each one patient. The 3-year survival for group A was 98+/-2%, for group B 96+/-3%, and for group C 100+/-0% (P=ns). Freedom from reoperation for group A was 98+/-2%, for group B 96+/-3%, and for group C 88+/-8% (P=ns). Four patients developed severe or moderate AI, thus freedom from severe and moderate AI for group A was 100+/-0%, for group B 88+/-8%, and for group C 94+/-5% (P=ns). During follow-up no thromboembolic or bleeding events were noticed.

CONCLUSIONS

Our data show that the preoperative diameter of the aortic root has no impact on the longevity of the repair. Thus, the reimplantation technique can be recommended for all patients presenting with an aortic root aneurysm and normal leaflets regardless of the aortic root diameter.

[Genetics and prevention of genetic aortic syndromes (GAS) and of the Marfan syndrome]

BACKGROUND

Genetic aortic syndromes are autosomal-dominantly heritable aneurysms of the thoracic aorta, which carry a high risk of aortic rupture or acute thoracic aortic dissection at young age.

OBJECTIVES

We introduce the reader to the principles of genetic diagnostics and the medical and surgical prevention of thoracic aortic dissection in patients with genetic aortic syndromes.

METHODS

A cardiologist, a health economist, a patient representative, a heart surgeon, and a molecular geneticist teamed up to elucidate their perspective on major aspects of genetics and prevention of genetic aortic syndromes.

RESULTS

Genetic aortic syndromes reflect a broad spectrum of diverse disease entities comprising the Marfan syndrome, the Loeys-Dietz syndrome or the vascular Ehlers-Danlos syndrome. The diagnosis of each respective disease entity requires combined assessment of phenotype and genotype information. A medical prevention of aortic complications such as dissection is mandatory although a curative therapy currently appears unlikely in humans. The single most important measure against acute aortic dissection is the preventive replacement of the aortic root, where valve preserving techniques appear preferable. Comprehensive prophylaxis including molecular diagnostics seem reasonable also from an economic point of view.

DISCUSSION

Optimal prevention requires individualization of concepts, which entail a detailed diagnostic characterization of each specific genetic aortic syndrome including characterization of the genotype.

Intraoperative Bypass Graft Angiography: Cooperation between Cardiologist and Surgeons in the Operation Room for Optimal Postoperative Results - Is this the Way for the Future?

OBJECTIVE

To confirm the quality of total arterial CABG carried out using the left internal thoracic artery (LITA) and a radial artery (RA) T-graft and distal anastomoses immediately in the OR, we developed a new technique using intraoperative graft angiography.

METHODS

A 5-Fr sheath is inserted in the proximal radial artery stump, through which a catheter for LITA angiography is later introduced. From July 2004 to March 2005, 23 patients underwent total arterial CABG with the T-graft and intraoperative graft angiography.

RESULTS

On-pump CABG was performed in 22 patients and off-pump CABG in 1 patient. Mean procedure time for the angiography was 13.7 +/- 7.3 minutes, and mean fluoroscopy time was 6.2 +/- 4.6 minutes. In two patients, the RA-marginal artery side-to-side anastomosis was stenosed and had to be revised as demonstrated by graft angiography. In one patient, the RA was kinked and in another, there was a kinking of the LITA. In both cases, kinking was corrected. The remaining anastomoses were seen to have unobstructed flow with no evidence of stenosis.

CONCLUSIONS

Intraoperative graft angiography can be performed in patients undergoing total arterial CABG. This concept of intraoperative cooperation between an interventional cardiologist and surgeons could significantly improve the operative outcome in CABG surgery.

[Modified endothelial cells in graft vasculopathy]

Occlusion of venous bypass grafts after coronary revascularization grafting represents the main reason for re-do operations. Arterial pressure as well as mechanical injury of the venous wall lead to endothelial dysfunction, causing intimal hyperplasia with luminal stenosis and eventually occlusion. In the transplanted heart, coronary artery disease limits the long-term success of cardiac transplantation. The disease is characterized by the interaction of activated immunologic cells and donor epicardical and microvascular endothelium. The ex vivo modification of endothelial cells may offer a therapeutic option to overcome both kinds of graft vasculopathy. Seeding of human endothelial cells on artificial and bioartificial acellularized vessel matrices has proven possible. The use of xenogenic matrices initially acellularized and recellularized with autologic endothelial cells and myofibroblasts may help to overcome the lack of vascular and valvular grafts with long durability. In addition, gene therapeutic methods to modify the function of such endothelial cells may offer a new therapeutic strategy, such as over-expression of nitric monoxide or inhibition of matrix metalloprotinases. First results of large animal studies show promising results and may lead to the first clinical trials in the near future.