Propionibacterium acnes endocarditis: a case series.

OBJECTIVES: Propionibacterium acnes remains a rare cause of infective endocarditis (IE). It is challenging to diagnose due to the organism's fastidious nature and the indolent presentation of the disease. The purpose of this study was to describe the clinical presentation and management of P. acnes IE with an emphasis on the methods of diagnosis. METHODS: We identified patients from the Cleveland Clinic Infective Endocarditis Registry who were admitted from 2007 to 2015 with definite IE by Duke Criteria. Propionibacterium acnes was defined as the causative pathogen if it was identified in at least two culture specimens, or identified with at least two different modalities: blood culture, valve culture, valve sequencing or histopathological demonstration of microorganisms. RESULTS: We identified 24 cases of P. acnes IE, 23 (96%) of which were either prosthetic valve endocarditis or IE on an annuloplasty ring. Invasive disease (71%) and embolic complications (29%) were common. All but one patient underwent surgery. Propionibacterium acnes was identified in 12.5% of routine blood cultures, 75% of blood cultures with extended incubation, 55% of valve cultures, and 95% of valve sequencing specimens. In 11 of 24 patients (46%), no causative pathogen would have been identified without valve sequencing. CONCLUSIONS: Propionibacterium acnes almost exclusively causes prosthetic valve endocarditis and patients often present with advanced disease. The organism may not be readily cultured, and extended cultures appear to be necessary. In patients who have undergone surgery, valve sequencing is most reliable in establishing the diagnosis.

Lung transplantation in a recipient with novel 2009 H1N1 influenza: lessons learned.

Immunosuppressed patients are at an increased risk for severe disease from influenza A (H1N1). We report a case of a patient who died of septic complications from H1N1 acquired at the time of single lung transplant.

Allograft entrapment after lung transplantation: a simple solution using a pleurocutaneous catheter.

BACKGROUND: Chronic pleural effusion following lung transplantation (LTx) is often responsible for respiratory insufficiency and can lead to lung entrapment. Decortication carries considerable morbidity, and extended use of tube thoracostomy is not practical. We have utilized an indwelling pleurocutaneous catheter in the setting of intractable post-transplant effusion and have reviewed our experience to determine whether this strategy: 1) facilitates resolution of effusion, and 2) adequately palliates lung entrapment. METHODS: Twelve PleurX (Denver Biomedical, Golden, CO, USA) catheters were placed in 9 LTx patients (6 unilateral, 3 bilateral) for refractory pleural effusions after standard tube thoracostomy drainage failed (12/12). Two-thirds of the patients (8/12) also had concomitant lung entrapment. RESULTS: There was no operative mortality. Median time from LTx to catheter placement was 79 days (range 21-769). Catheter use achieved the desired outcome in 11/12 placements. Catheters remained in place for a median of 86 days (range 35-190). Direct catheter-related complications included hemothorax (1) and empyema (1). CONCLUSION: Use of an indwelling pleurocutaneous catheter effectively achieves its intended goals of pleurodesis and management of entrapped lungs after LTx.

Double valve endocarditis.

BACKGROUND: There are little data concerning surgical outcomes in patients with native valve endocarditis affecting both the aortic and mitral valves. METHODS: From 1977 to 1998, 54 patients had simultaneous aortic and mitral valve grafting for native valve endocarditis. In 78%, mitral valve involvement was limited to the anterior leaflet, suggesting a jet lesion from the aortic valve. Surgical strategies included 31 valve repairs and valve replacement with mechanical (34), bioprosthetic (34), or allograft (9) prostheses. Three hundred twenty-five patient-years of follow-up were available for analysis (mean 6.0 +/- 4.8 years). RESULTS: There were no hospital deaths. Ten-year survival was 73%. Ten-year freedom from recurrent endocarditis was 84%, with risk peaking at 3 months, followed by a constant risk of 1.3%/yr. Choice of valvar procedure did not influence mortality or reinfection risk. CONCLUSIONS: The most common pattern of double valve infection was a jet lesion on the anterior mitral leaflet. Surgical treatment has late survival and freedom from reinfection similar to those of patients with single heart valve infection.

The atherosclerotic aorta at aortic valve replacement: surgical strategies and results.

BACKGROUND: Aortic valve replacement in patients with severe atherosclerosis of the ascending aorta poses technical challenges. The purpose of this study was to examine operative strategies and results of aortic valve replacement in patients with a severely atherosclerotic ascending aorta that could not be safely crossclamped. PATIENTS AND METHODS: From January 1990 to December 1998, 4983 patients had aortic valve surgery; of these, 62 (1.2%) patients had a severely atherosclerotic ascending aorta and required hypothermic circulatory arrest to facilitate aortic valve replacement. They form the study group. RESULTS: All patients had hypothermic circulatory arrest, but several different strategies were used to manage the ascending aorta. These techniques included aortic valve replacement with the use of hypothermic circulatory arrest (39%), ascending aortic endarterectomy (26%), ascending aortic replacement (19%), aortic inspection and crossclamping during hypothermic circulatory arrest (10%), and balloon occlusion of the ascending aorta (6%). Duration of hypothermic circulatory arrest was substantially longer for patients having aortic valve replacement with hypothermic circulatory arrest than for all other strategies. Hospital mortality was 14%, and 10% of patients had strokes. Increasing New York Heart Association functional class and impaired left ventricular function were risk factors for hospital mortality. Choice of operative technique did not influence patient outcome; however, no patient who underwent replacement of the ascending aorta had a stroke. CONCLUSIONS: Aortic valve replacement in patients with severe atherosclerosis of the ascending aorta is associated with increased operative morbidity and mortality. Complete aortic valve replacement during hypothermic circulatory arrest, the "no-touch" technique, requires a prolonged period of circulatory arrest. Ascending aortic replacement is a preferred technique, as it requires a short period of hypothermic circulatory arrest and results in comparable mortality with a low risk of stroke.

Improved lower esophageal sphincter manometry: application of the end-hole recording technique in vivo.

The recommendation to use a thin end-hole catheter for lower esophageal (LES) manometry has a strong theoretic background supported by previous in vitro studies. The pressure in the closed sphincter is measured, and the problem of pressure asymmetry eliminated. In this study the advantage and applicability of an end-hole catheter compared with the composite side-hole catheter for LES manometry was tested in vivo in dogs and human subjects. Pull-through manometry was performed with a continuously infused composite four-lumen catheter with one central channel and three side-hole channels enabling simultaneous end-hole and side-hole recording of LES pressure. A pull-through produced one end-hole and three side-hole pressure registrations. The end-hole recorded resting sphincter pressure was 19.7 +/- 4.5 cm H2O in 6 dogs and 9.9 +/- 6.8 cm H2O in 89 human subjects (volunteers and patients). The side holes recorded higher pressures, longer high-pressure zones, and obvious differences--asymmetry--between the three channels. The correlation between the side-hole and end-hole recordings was equally poor with regard to both pressure and length, with r values from 0.48 to 0.61. The relative difference between the end hole and side holes was most pronounced in low-pressure sphincters. In the dogs the end-hole and one side-hole channel always recorded LES pressure close to the expected 0 pressure during reflux, whereas the other two side-hole channels recorded high pressures. The present study proved the applicability of the end-hole technique for LES manometry in vivo in man. The end hole seemed to record true sphincter pressure.

Lower esophageal sphincter pressure in normal individuals and patients with gastroesophageal reflux. A comparison between end-hole and side-hole recording techniques.

The advantage of a single-lumen end-hole catheter compared with the usual composite side-hole catheter for lower esophageal sphincter (LES) manometry has been studied in vitro and in vivo. In the present study LES pull-through manometry was performed with a special catheter, enabling simultaneous end-hole and side-hole recording of LES pressure. Eighteen normal individuals with normal 24-h pH-monitoring (control group) and 42 reflux patients with pathologic 24-h pH-monitoring (reflux group) were studied. End-hole recorded resting sphincter pressure (RSP) in the control group was 15.4 +/- 5.0 cm H2O and in the reflux group 6.4 +/- 6.4 (p less than 0.0005). Side-hole recorded RSP (mean S1-S3) was 20.8 +/- 11.6 and 11.9 +/- 6.8, respectively (p less than 0.005). End-hole recorded total sphincter length (SL) in the control group was 34 +/- 9 mm and in the reflux group 27 +/- 12 (p less than 0.025) and abdominal sphincter length (ASL) 23 +/- 7 and 16 +/- 9, respectively (p less than 0.005). Side-hole recorded SL was 30 +/- 7 and 30 +/- 12, respectively (NS) and ASL 22 +/- 6 and 18 +/- 9 respectively (NS). After intake of 500 ml of water both LES pressure and length decreased in both groups but the separation between the groups was neither improved nor impaired. The results support the view that LES insufficiency is an important cause of gastroesophageal reflux. That LES had a lower pressure and was shorter in patients with reflux was best demonstrated by end-hole recorded pressure.

The contribution of the diaphragm and an intrinsic sphincter to the gastroesophageal antireflux barrier. An experimental study in the dog.

The components of the mechanical gastroesophageal antireflux barrier were studied in anesthetized dogs (15-18.5 kg). Pressure in the gastroesophageal junction area was recorded by pull-through manometry (using an infused end-hole-provided catheter) during gastric filling (distension) with water. In addition, the gastric volume at which reflux occurred was used as a measure of function and competence. Each dog was studied while intact and spontaneously breathing, after muscle relaxation, after excision of the left half of the diaphragm, and after death. In the intact dogs a barrier with a mean resting pressure of 20 (range, 14-26) cm H2O was recorded. During gastric filling the barrier pressure initially increased to 32 (16-42) cm H2O before steadily decreasing until reflux occurred. The highest pressure was recorded with 625 ml (250-1500 ml) in the stomach. Reflux occurred at a gastric volume of 3200 ml (2300-4000 ml). Muscle relaxation changed neither resting pressure nor reflux volume significantly. After excision of the left half of the diaphragm a barrier with a resting pressure of 15 (6-22) cm H2O was still recorded. Reflux then occurred at a gastric volume of 1400 ml (500-2500 ml). In dead dogs no pressure barrier could be recorded, and reflux was provoked already by 500 ml (250-750 ml) in the stomach. The presence of a mechanical barrier also after excision of the left half of the diaphragm, as evidenced by both pressure and reflux volume, can only be explained by an intrinsic sphincter, a lower esophageal sphincter (LES). However, the experiments also showed that the diaphragm contributed to the competence of the LES. This contribution was at first passive.

The problem of lower esophageal sphincter manometry. An experimental study in vitro.

The relation between sphincter pressure recorded by manometry and sphincter function was studied in three different in vitro models of the lower esophageal sphincter (LES). - A LES was simulated on gastroesophageal specimens by application of external pressure (A Starling model - model I), rubber band(s) (model II), or loaded plastic band loop(s) (model III). - Pressure in the simulated sphincters (SP) was recorded by pull-through manometry using either a continuously infused 4.5 mm thick composite catheter with three sidehole channels and a central longer thin endhole channel or a simple thin endhole catheter. SP was recorded with empty stomach (RSP), during gastric filling and at reflux. Gastric pressure at which reflux occurred - opening pressure (OP) - was used as a measure of function of the simulated sphincter. - RSP recorded by the sideholes was the same or higher in model I, higher in model II, and lower in model III than RSP recorded by the endhole. OP was equal to RSP (endhole) in model I but lower than RSP (endhole) in models II and III. External support to the esoPhageal specimen was recorded by the corresponding sidehole as increased pressure. - The models demonstrated a complex relation between recorded SP and OP that, however, could be explained by the different properties of the three models and La Place's law. Both sideholes and endhole seemed to record true pressures but the endhole recorded the pressure in the closed sphincter and was insensitive to pressure asymmetria caused by external support. These studies suggest that RSP recorded by a thin endhole catheter is a direct measure of sphincter strength which we expect determines sphincter function.

Studies of the dynamic response of esophageal manometry systems.

Manometry with fluid-filled catheter systems remains an important technique to study esophageal physiology. The influence of mode of infusion, infusion flow rate, and catheter dimensions on the dynamic response and compliance of such systems was studied. To test the dynamic response, a method based on the step response was developed and applied. A pressure impulse--a step function--was produced by burning off a balloon connected to the system. The response to this well-defined impulse recorded by the system--the step response--was analyzed. The highest frequency to which the system responded satisfactorily--the limiting frequency--was calculated and used as a measure of performance. Compliance and inherent postocclusion pressure rise rate were also determined. In low-compliance systems noninfused or infused by hydraulic capillary infusion, limiting frequencies from 8 to 20 Hz were found, and this was much higher than in a high-compliance system infused by a syringe infusion pump. Smaller diameter and increased length of the manometry catheter decreased the limiting frequency. Increased infusion flow rate did not increase the limiting frequency. The step response test seems to be a simple test of dynamic response that can contribute to better understanding of problems involved in pressure recording with fluid-filled catheter systems. Well-performing fluid-filled manometry systems are adequate for esophageal manometry. Inherent postocclusion pressure rise rate is not a measure of dynamic response, and compliance is not the only determinant of performance.

Strut fractures in De Bakey aortic valves.

In two of six patients with a De Bakey aortic valve prosthesis implanted in 1973, strut fractures occurred after 7.5 and 9 years, respectively. In one case the cage and ball embolized and the outcome was fatal. The second case was recognized before embolization had occurred, and the valve could be successfully replaced. Valve replacement is recommended in cases with a De Bakey aortic prosthesis of the described type.

A case of total bilateral spontaneous pneumothorax.

Bilateral spontaneous pneumothorax with almost complete collapse of the lungs in a 29-year-old man is reported. On admission to hospital the patient was in moderate respiratory distress, but the arterial blood gases were normal. Initially he was treated with bilateral tube drainage. Thoracotomy with parietal pleurectomy was later done on the right side to prevent recurrence.

Influence of hiatal hernia on lower esophageal sphincter function.

Sliding hiatal hernia has long term been implicated as a cause of lower esophageal sphincter (LES) incompetence and gastroesophageal reflux. The physics of LES function in hiatal hernia were investigated in in vitro and in vivo experiments. In vitro models of sliding hernias were constructed from excised canine gastroesophageal specimens. A "sphincter" was simulated with a rubber band around the gastroesophageal junction. It was found that placement of a ligature "hernia ring" on the stomach increased the opening pressure of the model sphincter. Addition of a tissue "hernia sac" sutured to the esophagus above the sphincter further increased the opening pressure, the protective effect being related to the pressure transmitted from the stomach to the hernia sac. There was no fluid leakage from the hernia sac between the hernia ring and the stomach. In anesthetized dogs (in vivo model) gastric and esophageal pressures were measured during gastric infusion while the LES gas way to reflux. A ligature tied loosely around the stomach to simulate a "hernia ring" and a sliding hernia without a hernia sac increased both the opening and the closing pressures of the LES by 36 +/- 18% and 35 +/- 20% (mean +/- SD), respectively. The opening pressure was increased by a decrease in gastric wall tension at the gastroesophageal junction, which was caused by the decreased radius of the herniated portion of the stomach. Pressure transmitted from the stomach to the hernia sac added to the LES pressure, and thereby further increased the opening pressure of the sphincter. The results explain how gastroesophageal reflux may be prevented in patients with hiatal hernia. It was recognized that the hernia sac may protect the sphincter, provided that it inserts into the esophagus above the LES.

The lower esophageal sphincter: mechanisms of opening and closure.

Patients with and without gastroesophageal reflux cannot be separated on the basis of lower esophageal sphincter (LES) miximal pressure alone, suggesting that more than this single factor is involved in normal closure of the LES. The physics of the closure mechanism was investigated in vivo in one and in vitro in two models. In anesthetized dogs the gastric and esophageal pressures were measured during gastric infusion while the LES gave way to reflux. In vitro sphincters were simulated on flaccid rubber tubes and excised canine gastroesophageal specimens. In model I the sphincter was simulated by mounting the specimen in a chamber and applying external pressure. In model II a ligature with graded tension was applied around the specimen. Station pullback manometry and pressure variations during constant flow perfusion were studied for these sphincter models. An opening pressure and a closing pressure for the LES were defined. The wall tension of the stomach as a force contributing to sphincter opening was recognized, introducing the degree of gastric distension as an important factor in sphincter function. The sealing property of the mucosa was estimated. The length of the sphincter was suggested to contribute to sphincter competence by decreasing the importance of gastric wall tension in sphincter opening and by improving the mucosal seal.