Comparison of radiological and clinical results of balloon kyphoplasty according to anterior height loss in the osteoporotic vertebral fracture

Background context

Percutaneous kyphoplasty is effective for pain reduction and vertebral height restoration in patients with osteoporotic vertebral fractures. However, in cases of severely collapsed fractures involving the loss of more than 70% of the vertebral height, kyphoplasty is technically difficult to perform and the outcomes remain unknown.

Purpose

To compare the vertebral height restoration rate, kyphotic angle, and clinical results of patients who underwent kyphoplasty according to the degree of anterior vertebral height loss. In addition, to determine the feasibility and effects of kyphoplasty on severely collapsed osteoporotic vertebral fractures.

Study design/setting

A retrospective study.

Patient sample

A total of 129 patients (145 vertebrae) who underwent kyphoplasty for osteoporotic painful vertebral fracture and followed up for more than 1 year between September 2005 and August 2012 were recruited for the analysis.

Outcome measures

The patients' kyphotic angle, anterior vertebral height, and anterior vertebral height restoration ratio 1 year after surgery were compared. Pre- and postoperative pain around the fractured vertebra and the radiological and clinical results according to bone mineral density (BMD) were also compared.

Methods

Patients were divided into three groups for comparison, according to radiographic findings. Patients with an anterior height compression ratio more than 70% at the time of fracture comprised Group I, patients with a compression ratio of 50–70% comprised Group II, and those with a compression ratio of 30–50% comprised Group III.

Results

Group I showed a greater extent of anterior height restoration immediately after surgery compared with the other groups, which noticeably decreased over time. All three groups showed significant restoration of the anterior vertebral height between pre- and postoperative values. The anterior vertebral height 1 year after surgery did not differ between Group I and Group II but was significantly higher in Group III. There was no correlation between the BMD and restoration or decrease of anterior vertebral height over time. Pain around the fractured vertebra significantly decreased in all groups immediately and 1 year after surgery compared with preoperative levels, although the pain level 1 year after surgery did not differ significantly between the groups.

Conclusions

In patients with an anterior vertebral compression ratio more than 70% because of osteoporotic vertebral fracture, although the anterior height and kyphotic angle were significantly lower than those of patients with an anterior vertebral compression ratio of 30% to 50%, kyphoplasty significantly improved the degree of pain, restored the anterior vertebral height, and maintained the kyphotic angle. Therefore, kyphoplasty can be a useful approach in patients with an anterior vertebral compression ratio more than 70%.     

A new model for the study of secondary intra-abdominal hypertension in rats

Background

To build a new and appropriate model of secondary intra-abdominal hypertension (IAH) in rats.

Methods

A total of 32 female Sprague–Dawley rats were randomized into four groups. Group I: the rats were hemorrhaged to a mean arterial pressure (MAP) of 40 mm Hg for 1 h and portal hypertension was induced by partial ligation of the portal vein 1 h later; Group II: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 1 h; Group III: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 2 h; Group IV: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 2 h, and a specially designed abdominal restraint device was used. After these procedures, respectively, the collected blood was reinfused and lactated Ringer solution was continuously infused until the secondary IAH model was established.

Results

No models were built in Groups I, II, and III. One rat died in Group IV after portal vein ligation, and all the remaining rats successfully developed IAH; the success rate was 87.5%. During the resuscitation period, the average time was 5.26 ± 0.59 h and the average total infusion volume was 665.5 ± 86.04 mL/kg.

Conclusion

A rat model of secondary IAH was successfully established by resuscitation after a combination of inducing portal hypertension, hemorrhaging to a MAP of 40 mm Hg for 2 h, and using an abdominal restraint device. All these criteria mimic key etiological factors for the development of secondary IAH.     

Biomechanical evaluation of fracture fixation constructs using a variable-angle locked periprosthetic femur plate system

Background

In the United States there are more than 230,000 total hip replacements annually, and periprosthetic femoral fractures occur in 0.1–4.5% of those patients. The majority of these fractures occur at the tip of the stem (Vancouver type B1). The purpose of this study was to compare the biomechanically stability and strength of three fixation constructs and identify the most desirable construct.

Methods

Fifteen medium adult synthetic femurs were implanted with a hip prosthesis and were osteotomized in an oblique plane at the level of the implant tip to simulate a Vancouver type B1 periprosthetic fracture. Fractures were fixed with a non-contact bridging periprosthetic proximal femur plate (Zimmer Inc., Warsaw, IN). Three proximal fixation methods were used: Group 1, bicortical screws; Group 2, unicortical screws and one cerclage cable; and Group 3, three cerclage cables. Distally, all groups had bicortical screws. Biomechanical testing was performed using an axial–torsional testing machine in three different loading modalities (axial compression, lateral bending, and torsional/sagittal bending), next in axial cyclic loading to 10,000 cycles, again in the three loading modalities, and finally to failure in torsional/sagittal bending.

Results

Group 1 had significantly greater load to failure and was significantly stiffer in torsional/sagittal bending than Groups 2 and 3. After cyclic loading, Group 2 had significantly greater axial stiffness than Groups 1 and 3. There was no difference between the three groups in lateral bending stiffness. The average energy absorbed during cyclic loading was significantly lower in Group 2 than in Groups 1 and 3.

Conclusions

Bicortical screw placement achieved the highest load to failure and the highest torsional/sagittal bending stiffness. Additional unicortical screws improved axial stiffness when using cable fixation. Lateral bending was not influenced by differences in proximal fixation.

Clinical relevance

To treat periprosthetic fractures, bicortical screw placement should be attempted to maximize load to failure and torsional/sagittal bending stiffness.     

The effect of metallic tracheal stents on radiation dose in the airway and surrounding tissues

Background

Metallic airway stents are often used in the management of central airway malignancies. The presence of a metallic foreign body may affect radiation dose in tissue. We studied the effect of a metallic airway stent on radiation dose delivery in a phantom and an in vivo porcine model.

Methods

A metallic tracheal stent was fitted onto a support in a water phantom. Point dosimeters were positioned in the phantom around the support and the stent. Irradiation was then performed on a linear accelerator with and without the stent. Metallic tracheal stents were deployed in the trachea of three pigs. Dosimeters were implanted in the tissues near (Group 1) and away (Group 2) from the stent. The pigs were then irradiated, and the dose perturbation factor was calculated by comparing the actual dose detected by the dosimeters versus the planned dose.

Results

The difference in the dose detected by the dosimeters and the planned dose ranged from 1.8% to 6.1% for the phantom with the stent and 0%–5.3% for the phantom without the stent. These values were largely within the manufacturer's specified error of 5%. No significant difference was observed in the dose perturbation factor for Group 1 and Group 2 dosimeters (0.836 ± 0.058 versus 0.877 ± 0.088, P = 0.220) in all the three pigs.

Conclusions

Metallic airway stents do not significantly affect radiation dose in the airway and surrounding tissues in a phantom and porcine model. Radiation treatment planning systems can account for the presence of the stent. External beam radiation can be delivered without concern for significant dose perturbation.     

Side-to-side nerve bridges reduce muscle atrophy after peripheral nerve injury in a rodent model

Background

Peripheral nerve injury can result in muscle atrophy and long-term disability. We hypothesize that creating a side-to-side bridge to link an injured nerve with a healthy nerve will reduce muscle atrophy and improve muscle function.

Methods

Sprague-Dawley rats were divided into four groups (n = 7 per group). Group 1: transection only—a 10-mm gap was created in the proximal tibial nerve; group 2: transected plus repaired—the transected tibial nerve was repaired; group 3: transected plus repaired plus nerve bridge—transected nerve repaired with a distal nerve bridge between the tibial and peroneal nerves via epineurial windows; and group 4: transected plus nerve bridge—transected tibial nerve left unrepaired and distal bridge added. Gait was assessed every 2 wk. At 90 d the following measures were determined: gastrocnemius mass, muscle and nerve nuclear density, and axonal infiltration into the nerve bridge.

Results

Groups 3 and 4 had greater improvements in walking track recovery than groups 1 and 2. Group 3's gastrocnemius muscles exhibited the least amount of atrophy. Groups 1, 2, and 4 exhibited greater histologic appearance of muscle breakdown compared with group 3 and control muscle. Finally, most bridges in groups 3 and 4 had neuronal sprouting via the epineurial windows.

Conclusions

Our study demonstrated reduced muscle atrophy with a side-to-side nerve bridge in the setting of peripheral nerve injury. These results support the application of novel side-to-side bridges in combination with traditional end-to-end neurorrhaphy to preserve muscle viability after peripheral nerve injuries.     

Abdominal ultrasound versus hepato-imino diacetic acid scan in diagnosing acute cholecystitis—what is the real benefit?

Background

Acute cholecystitis is one of the most common surgical problems, yet substantial debate remains over the utility of simple examination, abdominal ultrasound (AUS), or advanced imaging such as hepato-imino diacetic acid (HIDA) scan to support the diagnosis.

Materials and methods

The preoperative diagnostic workup of patients who underwent cholecystectomy with histologically confirmed acute cholecystitis was reviewed to calculate the sensitivity of AUS, HIDA scan, or both. In addition, the sensitivity of the commonly described ultrasonographic findings was assessed.

Results

From 2010 through 2012, 406 patients among 9087 reviewed charts presented to the emergency department with acute upper abdominal pain and met inclusion criteria. 32.5% (N = 132) of patients underwent AUS only, 11.3% (N = 46) underwent HIDA scan only, and 56.2% (N = 228) had both studies performed for workup. 52.7% (N = 214) of patients had histopathologically confirmed acute cholecystitis. The sensitivities of AUS, HIDA, and AUS combined with HIDA for acute cholecystitis were 73.3% (95% confidence interval [CI] = 66.3%–79.5%), 91.7% (95% CI = 86.2%–95.5%), and 97.7% (95% CI = 93.4%–99.5%), respectively. Although of limited sensitivity, AUS findings of sonographic Murphy sign, gallbladder distension, and gallbladder wall thickening were associated with a diagnosis of acute cholecystitis.

Conclusions

The sensitivity of AUS for diagnosing acute cholecystitis in patients with acute upper abdominal pain is limited. The addition of a HIDA scan in the diagnostic workup significantly improves sensitivity and can add valuable information in the appropriate clinical setting.     

Predictors of early lung function in patients with congenital diaphragmatic hernia

Purpose

Long-term pulmonary outcomes of congenital diaphragmatic hernia (CDH) have demonstrated airflow obstruction in later childhood. We examined pulmonary function data to assess what factors predict lung function in the first three years of life in children with CDH.

Methods

This was a retrospective study of patients treated for CDH who underwent infant pulmonary function testing (IPFT) between 2006 and 2012. IPFT was performed using the raised volume rapid thoracoabdominal compression technique and plethysmography.

Results

Twenty-nine neonates with CDH had IPFTs in the first 3 years of life. Their mean predicted survival using the CDH Study Group equation was 63% ± 4%. Fourteen infants (48%) required extracorporeal membrane oxygenation (ECMO). The mean age at IPFT was 85.1 ± 5 weeks. Airflow obstruction was the most common abnormality, seen in 14 subjects. 12 subjects had air trapping, and 9 demonstrated restrictive disease. ECMO (p = 0.002), days on the ventilator (p = 0.028), and days on oxygen (p = 0.023) were associated with restrictive lung disease.

Conclusion

Despite following a group of patients with severe CDH, lung function revealed mild deficits in the first three years of life. Clinical markers of increased severity (ECMO, ventilator days, and prolonged oxygen use) are correlated with reduced lung function.     

Promotion of tracheal cartilage growth by intra-tracheal injection of basic fibroblast growth factor (b-FGF)

Purpose

Basic fibroblast growth factor (b-FGF) is a very effective growth factor that induces the proliferation of chondrocytes. This study aimed to investigate whether intra-tracheally-injected b-FGF solution promotes the growth of tracheal cartilage.

Methods

Group 1: 500 μl of distilled water was injected at the posterior wall of the cervical trachea of New Zealand white rabbits by using a tracheoscope (n = 5). Group 2: 100 μg/500 μl of b-FGF solution was injected at the posterior wall of the cervical trachea (n = 5). Group 3: Biodegradable gelatin hydrogel microspheres incorporating 100 μg/500 μl of b-FGF solution were injected at the posterior wall of the cervical trachea (n = 5). All animals were sacrificed 4 weeks later, and the outer diameter and luminal area of the cervical trachea at the site of b-FGF injection were measured.

Results

The cervical tracheas in the two b-FGF injection groups were spindle-shaped and had a maximum diameter at the injection site. The median outer diameter of the cervical trachea in Groups 1, 2, and 3 was 7.3, 8.0, and 8.0 mm, respectively, showing a significant difference among Groups 1, 2, and 3 (P = 0.04). The median luminal area in Groups 1, 2, and 3 was 27.4, 29.4, and 32.1 mm², respectively. The ad hoc test showed a marginally significant difference only between groups 1 and 3 (p = 0.056).

Conclusion

Intra-tracheal injection of slowly released b-FGF enlarged the tracheal lumen.     

Sensitivity of endoscopic retrograde cholangiopancreatography standard cytology: 10-y review of the literature

Background

Biliary strictures present a unique diagnostic challenge to clinicians as they can be caused by both benign and malignant conditions. With the high mortalities associated with hepatopancreaticobiliary malignancies, accurate and rapid tissue diagnosis is imperative and typically done before initiation of treatment. However, the exact sensitivity of standard cytology from endoscopic retrograde cholangiopancreatography (ERCP) to diagnose malignancy remains unclear because of wide distribution of reported values in the literature. Furthermore, the use of radical surgery to obtain tissue when cytology is indeterminate has led to questions about the role of ERCP in patients with biliary strictures.

Methods

A PubMed search was conducted using the terms ERCP, cytology, and brushings. Articles reviewed were published between 2002 and 2012, had patient population with biliary stricture, and had ERCP brushing results and final pathology available for review. The cytology and pathology data were abstracted from each study, and the combined overall sensitivity was calculated.

Results

Sixteen studies were identified, with sensitivities ranging from 6%–64% and 99% confidence intervals (CIs) ranging from ±6% to ±32%. A combined total of 1556 patients were included, with positive ERCP cytology results in 358 cases. On final pathology, however, 861 patients were positive for malignancy. When the data were combined, we found an overall sensitivity of 41.6% ± 3.2% (99% CI) with a negative predictive value of 58.0% ± 3.2% (99% CI).

Conclusions

ERCP brushings suffer from low sensitivity and negative predictive value. This study questions the utility of ERCP to change the surgical management of these diseases in patients with radiographic evidence of a neoplasm or high suspicion of a malignancy.     

The Comparisons of Hepatitis C Virus RNA Level Between Intraoperative Blood Salvage (Cell Saver) and Systemic Hepatitis C Virus RNA Kinetics During Liver Transplantation

Background

Cell Saver (CS; Haemonemic Corp, Braintree, Mass, United States) is frequently used to decrease transfusion requirements of homologous blood during liver transplantation (OLT). However, the use of CS in hepatitis C virus (HCV)-infected recipients is still debated owing to the potential elevation of HCV RNA level. In this study, we compared HCV RNA levels of CS blood with a series of blood samples obtained from HCV-infected OLT recipients.

Methods

Twelve HCV-infected patients with >50,000 copies/mL of HCV RNA were enrolled. HCV RNA was measured immediately after induction (I), at the end of anhepatic period (II), at the end of operation (III), and from the first returned blood in CS (CSb). HCV RNA level at each time period was compared.

Results

HCV RNA levels ranged from 77,931 to 9,072,000 copies/mL at I. When compared to I, HCV RNA levels were reduced to 11.1% ± 13.0% and 0.7% ± 1.0% at II and III, respectively. Also, the RNA level reduced to 3.0% ± 2.0% of I after CS processing. The HCV RNA level at I was significantly higher than the levels at II, III, and CSb (P = .012, each), and the level at II was significantly higher than the level at III (P = .012). The HCV RNA level at CSb showed no statistical difference with the levels at II, but it was significantly higher than the level at III (P = .042).

Conclusions

The use of CS in HCV-infected OLT recipients seems to carry no additional risk with respect to intraoperative HCV RNA kinetics.     

Outcomes of Orthotopic Liver Transplantation in Non-malignant End-stage Liver Diseases

Background

Orthotopic liver transplantation (OLT) is an effective treatment for patients who have end-stage liver disease. The aim of this study is to compare outcomes of OLT in fulminant hepatic failure (FHF) and non-fulminant hepatic failure (non-FHF) patients.

Methods

A retrospective review of adult patients who underwent OLT for non-malignant end-stage liver diseases between 2002 and 2011 at Siriraj Hospital was performed. All explanted liver histopathology results were reviewed. The clinical factors and overall results of OLT were analyzed.

Results

Of the 137 patients, 72 patients had non-malignant diagnoses. Eleven patients were diagnosed with FHF, whereas 61 patients were in the non-FHF group. The most common indication for liver transplantation was chronic viral hepatitis. One- and 5-year survival rates (95% confidence interval) in the FHF group were 91% (51%–99%) and 91% (51%–99%), respectively, whereas those in the non-FHF group were 74% (61%–83%) and 66% (52%–77%), respectively. Multivariate cox regression analysis revealed no statistically significant difference of survival between both groups (P = .34).

Conclusions

The post-OLT outcomes in non-malignant patients were comparable between FHF and non-FHF groups in terms of survival. OLT remains the only therapeutic option for the FHF patients.     

Age and gender differences in substance screening may underestimate injury severity: a study of 9793 patients at level 1 trauma center from 2006 to 2010

Background

Although the relationship between psychoactive substance use and injury is known, evidence remains conflicting on the impact of substance use on clinical outcomes after injury. We hypothesized that preinjury substance use would negatively impact clinical outcomes.

Methods

National Trauma Registry American College of Surgeons identified patients (n = 9793) presenting to Duke Hospital from 2006 to 2010. Logistic regression models assessed potential predictors of receiving substance screening, mortality, length of stay, ventilator requirement, intensive care admission, or emergency department disposition.

Results

Forty-seven percent (4607/9793) of patients received blood alcohol screen (BAS) and 31% (3017/9793) received urine drug screen (UDS). Men were more likely to receive both BASs (P < 0.001) and UDSs (P = 0.001) than women after controlling for potential confounders. There was no significant difference between men and women over the legal limit for alcohol (OLLA; 27.2%, 95% confidence interval [CI]: 25.7%–28.8% versus 24.8%, 95% CI: 22.3%–27.5%). Similarly, younger patients more likely received both BASs (P < 0.001) and UDSs (P < 0.001) compared with older patients. The proportion of patients aged ≤45 y OLLA (26.5 %, 95% CI: 24.9%–28.2%) was similar to those aged >45 y OLLA (26.8%, 95% CI: 24.5%–29.3%). After controlling for potential confounders neither alcohol, nor tetrahydrocannabinol, nor cocaine was predictive of mortality, ventilator requirement, length of stay, or emergency department disposition, but a higher alcohol level (P = 0.0174) predicted intensive care admission.

Conclusions

Females and those aged >45 y are less likely to receive BASs and UDSs. Differential screening that is biased may place patients at risk for receiving inadequate care.     

Are flexion extension films necessary for cervical spine clearance in patients with neck pain after negative cervical CT scan?

Background

There are variations in cervical spine (CS) clearance protocols in neurologically intact blunt trauma patients with negative radiological imaging but persistent neck pain. Current guidelines from the current Eastern Association for the Surgery of Trauma include options of maintaining the cervical collar or obtaining either magnetic resonance imaging (MRI) or flexion-extension films (FEF). We evaluated the utility of FEF in the current era of routine computerized tomography (CT) for imaging the CS in trauma.

Materials and methods

All neurologically intact, awake, nonintoxicated patients who underwent FEF for persistent neck pain after negative CT scan of the CS at our level I trauma center over a 13-mo period were identified. Their charts were reviewed and demographic data obtained.

Results

There were 354 patients (58.5% male) with negative cervical CS CT scans who had FEF for residual neck pain. Incidental degenerative changes were seen in 37%—which did not affect their acute management. FEF were positive for possible ligamentous injury in 5 patients (1.4%). Two of these patients had negative magnetic resonance images and the other three had collars removed within 3 wk as the findings were ultimately determined to be degenerative.

Conclusions

In the current era, where cervical CT has universally supplanted initial plain films, FEF appear to be of little value in the evaluation of persistent neck pain. Their use should be excluded from cervical spine clearance protocols in neurologically intact, awake patients.     

A comparison of dynamic views using plain radiographs and thin-section three-dimensional computed tomography in the evaluation of fusion after posterior lumbar interbody fusion surgery

Background context

Accurate evaluation of the postsurgery status of interbody fusion is important in deciding the patient's treatment. Dynamic plain radiographs are used as a convenient method, but the accuracy is not so good.

Purpose

This study aimed to evaluate the usefulness of dynamic flexion-extension radiographs as a method for evaluating fusion, by comparing it with three-dimensional thin-section computed tomography (CT).

Study design

Prospective controlled study.

Methods

We conducted a prospective study with 108 patients (158 levels) who, diagnosed with severe spinal stenosis and Grade I and Grade II spondylolisthesis, underwent posterior lumbar interbody fusion (PLIF) surgery, with follow-up by dynamic plain radiographs, functional rating scale, and three-dimensional (3D) thin-section CT for 1 year after surgery. In the plain radiographs, we looked for less than 3° of lordotic angle change, less than 3 mm of translation between vertebral bodies, and no presence of halo signs; satisfying all the criteria was regarded as fusion (Group A), whereas failure to satisfy any condition was referred to as probable nonfusion (Group B) and if none were satisfied as nonfusion (Group C). The patients were classified into fusion or nonfusion groups based on CT. Correlation between plain radiographs and CT groups was analyzed. Moreover, clinical assessment and cross-comparison between observers were done.

Results

In 158 levels, 95 (60.8%) levels were classified into the fusion group by plain radiographs and 131 (83%) levels by CT. When we analyzed the results of each groups, in Group A, 78 (81.3%) levels belonged to the CT fusion group and 18 (18.7%) levels to the CT nonfusion group, in Group B, 51 (89.5%) and 6 (10.5%) levels, and in Group C, 2 (40%) and 3 (60%) levels, respectively. For each of the CT fusion group, a cross-comparison using dynamic radiographs reconfirmed 78 (59.5%) levels for Group A, 51 (38.9%) levels for Group B, and 2 (1.6%) levels for Group C; for the CT nonfusion groups, 18 (66.7%) levels, 6 (22.2%) levels, and 3 (11.1%) levels were for Groups A, B, and C, respectively. In clinical evaluation, all groups showed clear postsurgery improvement, but there was no statistically significant difference. In terms of observer-to-observer error and agreement between diagnoses, CT showed a statistically higher level of correlation than plain radiographs.

Conclusions

Dynamic flexion-extension radiographs cannot be seen as an objective standard in the evaluation of fusion after PLIF surgery. It would be desirable to confirm the fusion status by thin-section 3D-CT for an objective analysis.     

The Advanced Trauma Operative Management course—a two student to one faculty model

Background

The internationally recognized Advanced Trauma Operative Management (ATOM) course uses a 1:1 student-to-faculty teaching model. This study examines a two student to one faculty ATOM teaching model.

Materials and methods

We randomly assigned 16 residents to four experienced ATOM faculty members. Half started with the one-student model and the other half with the two-student model and then switched using the same faculty. Students and faculty completed forms on the educational value of the two models (1 = very poor; 2 = poor; 3 = average; 4 = good; and 5 = excellent) and identified educational preferences and recommendations.

Results

We assigned educational values for the 13 procedures as follows: All faculty rated the one-student model as excellent; six members rated the two-student model as excellent, and seven as good. Students rated 50%–75% as excellent and 12%–44% as good for the two-student model, and 56%–81% as excellent and 12%–44% as good for the one-student model. Given resource constraints, all faculty and 88% of students preferred the two-student model. With no resource constraints, 75% of students and 50% of faculty chose the two-student model. All faculty and students rated both models “acceptable.” Overall, 81% of students and 50% of faculty rated the two-student model better. All faculty members recommended that the models be optional; 94% of students recommended that they be either optional (50%) or a two-student model (44%). Performing or assisting on each procedure twice was considered an advantage of the two-student model.

Conclusions

The two-student teaching model was acceptable and generally preferred in this study. With appropriately trained faculty and students, the two-student model is feasible and should result in less animal usage and possibly wider promulgation.     

Advanced Age of Renal Transplant Recipients Correlates With Increased Plasma Concentrations of Interleukin-6, Chemokine Ligand 2 (CCL2), and Matrix Metalloproteinase 2, and Urine Concentrations of CCL2 and Tissue Inhibitor of Metalloproteinase 1

Background

Advanced age of renal transplant recipients (RTRs) has a negative impact on kidney allograft survival through impaired extracellular matrix degradation by the matrix metalloproteinases/tissue inhibitors of metalloproteinases (MMPs/TIMPs) system. Moreover, older RTRs are at risk of smoldering inflammation, known as inflammaging.

Aim

The aim of the study was to assess the impact of a RTR's age on plasma and urine concentrations of interleukin 6 (IL-6), chemokine ligand 2 (CCL2), and the MMPs/TIMPs system.

Material and Methods

One hundred fifty adult RTRs (8.7% ≥ 65 years) and 37 adult healthy volunteers (10.8% ≥ 65 years) were enrolled in the study. The studied factors (IL-6, CCL2, MMP-2, MMP-9, TIMP-1 and TIMP-2) were quantified in plasma and urine with enzyme-linked immunosorbent assay. The Mann-Whitney U test and Spearman's (r_s) rank correlation were applied, and differences with a P < .05 were considered statistically significant.

Results

There was a weak but significant positive correlation between increasing RTR's age and plasma IL-6 (r_s = 0.18, P = .028), CCL2 (r_s = 0.27, P = .001), and MMP-2 (r_s = 0.20, P = .017), as well as urine CCL2 (r_s = 0.16, P = 0.050) and TIMP-1 (r_s = 0.20, P = .014) concentrations.

Conclusions

Advancing age of RTRs correlates with increasing plasma IL-6 and CCL2 concentrations, reflecting smoldering inflammation (known as inflammaging) and alterations in MMPs/TIMPs profiles, especially with increased plasma MMP-2 and urine TIMP-1 concentrations.     

Effects of biventricular pacing on left heart twist and strain in a porcine model of right heart failure

Background

Biventricular pacing (BiVP) improves cardiac output (CO) in selected cardiac surgery patients, but response remains variable, necessitating a better understanding of the mechanism. Accordingly, we used speckle tracking echocardiography (STE) to analyze BiVP during acute right ventricular pressure overload (RVPO).

Materials and methods

In nine pigs, the inferior vena cava (IVC) was snared to decrease CO and establish a control model. Heart block was induced, the pulmonary artery snared, and BiVP initiated. Echocardiograms of the left ventricular midpapillary level were taken at varying atrioventricular delay (AVD) and interventricular delay (VVD) for STE analysis of regional circumferential strain (CS) and radial strain (RS). Echocardiograms were taken of the left ventricular base, midpapillary, and apex during baseline, IVC occlusion, and each BiVP setting for STE analysis of twist, apical and basal rotations, CS, RS, and synchrony. Indices were correlated against CO with mixed linear models.

Results

During IVC occlusion, CO correlated with twist, apical rotation, RS, RS synchrony, and CS (P < 0.05). During RVPO with BiVP, CO only correlated with RS synchrony and CS (P < 0.05). During AVD and VVD variations, CO was associated with free wall RS (P < 0.008). CO correlated with septal wall CS during AVD variation and free wall CS during VVD variation (P < 0.008).

Conclusions

In an open chest model, twist, RS, RS synchrony, and CS analyzed by STE may be noninvasive surrogates for changes in CO. During RVPO, changes in RS synchrony and CS with varying regional strain contributions may be the primary mechanism in which BiVP improves CO. Lack of correlation of remaining indices may reflect postsystolic function.     

Dakin solution alters macrophage viability and function

Background

Macrophages are important in wound defense and healing. Dakin's solution (DS), buffered sodium hypochlorite, has been used since World War I as a topical antimicrobial for wound care. DS has been shown to be toxic to host cells, but effects on immune cells are not well documented.

Materials and methods

DS at 0.5%, 0.125%, and ten-fold serial dilutions from 0.25%–0.00025% were evaluated for cellular toxicity on murine macrophages (J774A.1). The effect of DS on macrophage adhesion, phagocytosis, and generation of reactive oxygen species was examined. Macrophage polarization following DS exposure was determined by gene expression using quantitative real-time polymerase chain reaction.

Results

Concentrations of DS >0.0025% reduced macrophage viability to <5% in exposure times as short as 30 s. Similarly, phagocytosis of Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus flavus were significantly reduced at all tested concentrations by macrophages pretreated with DS. H₂O₂ production was reduced by 8%–38% following treatment with 0.00025%–0.125% DS. Macrophage adherence was significantly increased with >0.0025% DS after 15 min of exposure compared with controls. Quantitative real-time polymerase chain reaction demonstrated that DS exposure resulted in classical macrophage activation, with increased expression of inducible nitric oxide synthase 2, interferon-γ, and interleukin (IL)-1β.

Conclusions

DS at clinically used concentrations (0.025%–0.25%) was detrimental to macrophage survival and function. For optimal clinical use, understanding the impact of DS on macrophages is important as depletion may result in impaired pathogen clearance and delayed healing. These findings indicate that 0.00025% DS is a safe starting dose; however, optimal use of DS requires further validation with in vivo models.     

Difference in Outcomes Between Living Left Lobe Donors and Noncirrhotic Subjects Undergoing Left Lobe Resections

Objectives

The aim of this study was to compare short- and long-term outcomes between the living donors and patients without cirrhosis after left lobe resection.

Material and Methods

We retrospectively collected data from 40 left lobe donors (Group 1) and from 40 patients who had undergone left liver resection for various diseases (Group 2) from 2002 to 2010. In addition to preoperative parameters, we compared intraoperative variables as well as, short- and long-term outcomes, including postoperative complications and laboratory test results. The liver functions included total bilurubin (TB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), international normalized ratio (INR), and albumin (ALB) compared as well as changes in white blood cell (WBC) count and platelet count.

Results

The preoperative parameters of the two groups were comparable. There was significantly more blood loss in Group 2 than Group 1 (422.5 mL vs 318.8 mL; P = .001), leading to more autologous blood transfusions in Group 2 (P = .008). The other intraoperative variables were similar between the two groups. The overall postoperative complication rate was similar: 4% in Group 1 and 8% in Group 2 (P = .213); however, there were longer hospital stays and overall costs in Group 1 (P < .05). The total bilirubin level, AST, and ALT of Group 2 were worse than those in Group 1 during the early postoperative period. Upon long-term follow-up the postoperative platelet count decreased in the two groups compared with the preoperative levels.

Conclusion

The type and rate of complications following left hepatectomy were similar between donors and noncirrhotic hepatic patients. Nevertheless, more serious liver dysfunction postoperatively was observed among the patient group.     

Faut-il procéder à un dépistage du portage de Pseudomonas aeruginosa dans les services de réanimation ?

Objective

To evaluate the potential interest of screening of Pseudomonas aeruginosa on admission and during hospitalisation in intensive care units patients.

Method

A retrospective study was carried out in two adult ICU of the University-Hospital of Besançon in 2007. P. aeruginosa screening was performed on admission and once a week during ICU stay. Clinical samples positive with P. aeruginosa were collected.

Results

Among the 754 patients included, 146 had a screening sample positive giving an average incidence of 19.4 per 100 patients. Thirty-five were imported and 111 ICU-acquired. Sixty-one patients had at least one positive clinical sample, that is an incidence 8.1 cases per 100 admitted patients. Sensibility, specificity, positive and negative predictive values of screening as an indicator of subsequent infection were 54.1%, 86.9%, 26.6% and 95.6%, respectively.

Conclusion

Screening samples are necessary to assess P. aeruginosa endemicity in intensive care units. The high negative predictive value of screening suggests that use of specifics anti-Pseudomonas antimicrobials could be reduced. However, the benefit of this strategy remains to be evaluated.