Interactions of polysaccharide-based tissue adhesives with clinically relevant fibroblast and macrophage cell lines

The effects of polysaccharide-based tissue adhesives on cell survival and inflammatory cell activation were determined using in vitro mouse cell cultures. Cytotoxicity of tissue adhesives was evaluated by placing adhesives in direct contact with 3T3 fibroblast cells. Polysaccharide-based tissue adhesives composed of dextran aldehyde and star PEG amine were non-cytotoxic to fibroblasts; in contrast, a commercial adhesive composed of 2-octyl cyanoacrylate was highly cytotoxic to fibroblasts. The inflammatory potential of tissue adhesives was evaluated by exposing J774 macrophage cells to adhesives, and measuring TNF-alpha release from macrophages. Polysaccharide-based tissue adhesives did not elicit inflammatory TNF-alpha release from macrophages. These results suggest that polysaccharide-based tissue adhesives are non-cytotoxic and non-inflammatory; the results are therefore significant in the design of in vitro cell culture systems to study biomaterials.

Obstructive suburethral mass after transurethral injection of dextranomer/hyaluronic acid copolymer

Dextranomer/hyaluronic acid copolymer (Zuidex(R)) is a new bulking agent. There is little data about the complications of using this substance as urethral bulking agent for the treatment of urinary stress incontinence. We are presenting a 59-year-old female patient who developed a suburethral mass and urinary retention after zuidex urethral injection. A stepwise approach for treatment was followed. Complete excision of the mass was the only curative procedure that succeeded.

[Perioperative colloid administration: a survey of Spanish anesthesiologists' attitudes]

OBJECTIVES

To determine the availability of intravascular fluid volume replacement solutions in Spanish hospitals, to survey the extent of use of colloids by anesthesiologists, to ascertain the possible adverse effects they seek to prevent when using each solution, and to assess their level of knowledge about the subject.

MATERIAL AND METHODS

A questionnaire was administered over a period of 6 months (July 2004-January 2005). The questionnaire was available online at www.encuestacoloides.com. The address was distributed by e-mail to anesthesiologists of all the Spanish autonomous communities and published in the Revista Española de Anestesiología y Reanimación.

RESULTS

One hundred forty-two anesthesiologists responded. Crystalloids and colloids were widely available in most hospitals. Hydroxyethyl starch (HES) solutions were the colloids most often used (73%), followed by gelatins (28%). Dextran solutions, on the other hand, were no longer being used. The reasons the respondents gave for using these solutions were related to the time they remained in the vascular system, their greater effect of volume expansion, and the preservation of hemostasis. The most-feared complication was anaphylactic reaction to gelatins and there were concerns about the dose limit for infusion of HES solutions and about hemodynamic instability caused by dextran solutions. Fifty-four percent felt that scientific meetings provide little information about colloids and volume replacement.

CONCLUSIONS

There is widespread use of colloids other than dextran along with crystalloids for plasma volume replacement. Spanish anesthesiologists are clear about important concepts related to colloid use. However, a high percentage have doubts about certain fundamental issues. Continuing professional development opportunities related to intravascular fluid replacement therapy should be increased.

[Paraurethral abscess developing after mid-urethral Zuidex-injection in women with stress urinary incontinence -- management of complications and retrospective comparison with bladder neck located injection technique]

PURPOSE

To evaluate the cause and management of paraurethral abscess developing after injection of a mixture of hyaluronic acid and dextranomer (Zuidex) for treating stress urinary incontinence.

PATIENTS AND METHOD

A total of 127 women having undergone midurethral Zuidex injection and 34 women after endoscopically guided Deflux injection into the tissue around the bladder neck were followed up 1 to 24 months after the intervention. At follow-up, the paraurethral tissue was evaluated clinically by gynecologic examination and by introital ultrasound.

RESULTS

Thirteen of 127 women (10 %) having undergone midurethral Zuidex injection had a sterile paraurethral abscess that was treated by transvaginal puncture (1 to 3 punctures with removal of 10-60 ml of fluid per patient). No case of postoperative paraurethral abscess formation was demonstrated in the control group treated by Deflux injection into the area around the bladder neck.

CONCLUSIONS

Paraurethral abscess must be excluded in the postinterventional follow-up of patients after Zuidex injection. Patients in whom an abscess is demonstrated can be treated by transvaginal puncture. Abscess formation can be avoided by injecting dextranomer/hyaluronic acid into the area around the bladder neck.

Postoperative Ureteral Obstruction After Subureteral Injection of Dextranomer/Hyaluronic Acid Copolymer

PURPOSE

Subureteral injection of dextranomer/hyaluronic acid copolymer is widely accepted for the treatment of primary vesicoureteral reflux. Few studies document the incidence of surgically relevant postoperative obstruction or the characteristics of patients at risk.

MATERIALS AND METHODS

Four institutions had reported surgically relevant postoperative obstruction to representatives of Q-Med Scandinavia, the manufacturers of Deflux (dextranomer/hyaluronic acid). All children undergoing dextranomer/hyaluronic acid injection at these institutions were evaluated in this study. Patients requiring postoperative stenting were retrospectively reviewed for pertinent history, volume injected, technique of injection, duration of symptoms before intervention, duration of intervention and final outcome.

RESULTS

A total of 745 patients (1,155 ureters) underwent injection. Five patients (6 renal units, 7 ureters) required stenting for obstructive symptoms and hydronephrosis, of whom 4 immediately became symptomatic. All patients had been injected with up to 1 ml dextranomer/hyaluronic acid. Four patients (80%) had either a neurogenic bladder or dysfunctional voiding. All stents were placed and removed without complications, with complete resolution of symptoms in all patients. Length of stenting ranged from 2 to 6 weeks. No patient required open surgery. One of 2 patients undergoing postoperative voiding studies had development of recurrent vesicoureteral reflux.

CONCLUSIONS

Dextranomer/hyaluronic acid injection is associated with a small risk of postoperative ureteral obstruction requiring endoscopic intervention, with an overall incidence of less than 0.7% of patients injected. Patients with voiding dysfunction or neurogenic bladder may be at increased risk. Intervention with temporary ureteral stenting is effective, technically simple and curative.

Patient-perceived outcomes in the treatment of stress urinary incontinence: focus on urethral injection therapy

Intervention for stress urinary incontinence (SUI) is generally focused on minimizing urinary leakage. However, the overall impact of SUI therapy on patients' quality of life is, arguably, more important than leakage outcomes. We performed a literature search to investigate the effect of urethral injection therapy on quality of life. Significant quality-of-life improvements have been observed with a number of injectable agents, while there is a distinct lack of correlation between subjective and objective outcomes. Two studies comparing urethral injection therapy with surgical intervention found superior objective efficacy with surgery, but no significant differences in quality-of-life improvements. Personal goals of patients undergoing urethral injection are yet to be explored, but there may be willingness to trade a lower success rate in favor of a more minor treatment procedure. In conclusion, quality-of-life improvements after urethral injection appear significant and comparable to those obtained with surgery. Further study of patients' own perceptions, pre- and posttreatment, would be valuable.

Lung Collapse Induced by Pulmonary Hemorrhage: A Rare Complication of Hysteroscopy

Pulmonary hemorrhage is a rare but sometimes fatal complication of hysteroscopy. We present the first case report in which a healthy patient developed lung collapse induced by pulmonary hemorrhage after operative hysteroscopy. The possible etiologies of this rare complication are also discussed.

Ureteral obstruction after dextranomer/hyaluronic acid copolymer injection for treatment of secondary vesicoureteral reflux after renal transplantation

Ureteral obstruction after transurethral injection therapy for primary vesicoureteral reflux is known to occur in less than 1% of cases. We report the first case of a ureteral obstruction after transurethral injection of dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of secondary vesicoureteral reflux after renal transplantation. Loss of transplant function made reimplantation of the ureter necessary. A periureteral phlebitis and moderate foreign body reaction was found histologically, although the patient had received immunosuppressive therapy. Endoscopic therapy of secondary vesicoureteral reflux in patients after renal transplantation is a reasonable minimally invasive treatment option; however, severe complications may occur.

Simple aspiration technique to address voiding dysfunction associated with transurethral injection of dextranomer/hyaluronic acid copolymer

Dextranomer/hyaluronic acid copolymer (Zuidex) is currently under Food and Drug Administration investigation for use as a transurethral bulking agent to treat female stress urinary incontinence secondary to intrinsic sphincter deficiency. Urethral obstruction is a recognized complication of bulking agents. We describe an aspiration method to address iatrogenic voiding dysfunction resulting from this therapy.

Anaphylactoid reactions to Dextran 40 and 70: Reports to the United States Food and Drug Administration, 1969 to 2004

BACKGROUND

Clinical dextrans, such as Dextran 40 and Dextran 70, are associated with anaphylactoid reactions caused by dextran-reactive immunoglobulin G antibodies. When infused immediately before clinical dextrans, dextran 1 significantly reduces the incidence of severe anaphylactoid reactions. The objective of the study was to describe the frequency and characteristics of reports submitted to the United States Food and Drug Administration (FDA) for anaphylaxis or anaphylactoid events after clinical dextran administration.

METHODS

We searched the FDA's Adverse Event Reporting System for reports associated with a clinical dextran and describing anaphylaxis/anaphylactoid reactions. Our case definition for a probable anaphylaxis/anaphylactoid event required signs or symptoms from at least two body systems, with at least one sign or symptom being hypotension, vasodilation, or respiratory difficulty, and onset within 60 minutes. Other reports were considered possible cases if the reporter specifically described the reaction as anaphylaxis or an anaphylactoid reaction. Premier RxMarket Advisor provided estimates of total US hospitalizations with clinical dextran or dextran 1 administration from 2000 to 2004, based on discharge billing data from a sample of US hospitals. The IMS National Sales Perspective provided estimates of total doses of dextrans sold in the United States from 1999 to 2004, based on volumes of dextrans sold in a sample of retail and nonretail outlets.

RESULTS

The FDA received 366 clinical dextran adverse event reports from 1969 to 2004, of which 90 (24.6%) were anaphylaxis/anaphylactoid events. The ratio of hospitalizations where clinical dextran was administered to hospitalizations where dextran 1 was administered was 28.4:1. The expected ratio would be 1:1 if all clinical dextran patients had received dextran 1 pretreatment. The ratio of clinical dextran doses sold to dextran 1 doses sold in the United States was 38.6:1.

CONCLUSIONS

A high proportion of adverse event reports for clinical dextrans described anaphylaxis or anaphylactoid reactions. Hospital discharge and product sales data suggest that dextran 1 has not been used consistently before clinical dextran administration in recent years. To reduce the risk of anaphylactoid reactions, physicians should consider routine administration of dextran 1 before the infusion of a clinical dextran.

Traumatic axonal injury in the perisomatic domain triggers ultrarapid secondary axotomy and Wallerian degeneration

Traumatic axonal injury (TAI) arising from diffuse brain injury (DBI) results in focally impaired axonal transport with progressive swelling and delayed disconnection over several hours within brainstem axons. Neocortical DBI-mediated perisomatic axotomy does not result in neuronal death, suggesting that a comparably delayed axotomy progression was responsible for this unanticipated response. To evaluate delayed perisomatic axotomy, the current study was initiated. Rats received intracerebroventricular 10-kDa dextran followed by moderate midline/central fluid percussion injury (FPI) or FPI alone. At 15, 30, 60, and 180 min post-injury, light and transmission electron microscopy identified impaired axonal transport via antibodies targeting amyloid precursor protein (APP), while double-label fluorescent microscopy explored concomitant focal axolemmal alterations via dextran-APP co-localization. At 15 min post-injury, perisomatic TAI was identified with LM within dorsolateral and ventral posterior thalamic nuclei. Using TEM, many sustaining somata and related proximal/distal axonal segments revealed normal ultrastructural detail that was continuous with focal axonal swellings characterized by cytoskeletal and organelle pathology. In other cases, axotomy was confirmed by loss of axonal continuity distal to the swelling. By 30 min post-injury, perisomatic axotomy predominated. By 60-180 min, somatic, proximal axonal segment, and swelling ultrastructure were comparable to earlier time points although swelling diameter increased. Distal axonal segment ultrastructure now revealed the initial stages of Wallerian degeneration. The site of perisomatic axotomy did not internalize dextran, suggesting that its pathogenesis occurred independent of altered axolemmal permeability. Collectively, this DBI-mediated ultrarapid perisomatic axotomy and its sequelae further illustrate the varied axonal responses to trauma.

Cardiac arrest and resuscitation with an automatic mechanical chest compression device (LUCAS) due to anaphylaxis of a woman receiving caesarean section because of pre-eclampsia

We report a case of anaphylaxis with pulseless electrical activity (PEA)(verified by ECG and a radial intra-arterial line) in a 30-year-old woman who received 3G Promiten (dextran-1) and a prophylactic intra-venous infusion of Macrodex (dextran) for postoperative thromboembolism during caesarean section for pre-eclampsia in the 24th week of gestation. Manual chest compressions, followed by mechanical chest compressions (LUCAS, Jolife, Lund, Sweden), were performed for 50min before restoration of spontaneous circulation (ROSC). She awoke the next day with no sequelae. She had some suction cup marks on the sternum but otherwise no complications of the chest compressions. At follow up by phone 1 month later, she and her baby were doing well.

Periurethral granuloma following injection with dextranomer/hyaluronic acid copolymer for stress urinary incontinence

Periurethral injection of bulk-enhancing agents provides a simpler and cost-effective therapeutic approach for stress incontinence in women. We report a case of periurethral granuloma secondary to dextranomer/hyaluronic acid (Dx/HA) copolymer injection. A 73-year-old woman with history of radiotherapy for cervical carcinoma at the age of 55 presented with stress urinary incontinence. She underwent periurethral injection of Dx/HA copolymer, and incontinence was resolved. At 4 months postoperatively, a 3-4 cm noninflammatory painless mass in the external genitalia was noted. Cystic images compatible with urethral diverticula were seen in the magnetic resonance imaging scan, but voiding cystourethrography was unrevealing. Transvaginal tumor puncture yielded abundant creamy material, the culture of which was negative. Microscopic examination revealed refractile foreign material surrounded by foreign body giant cells. Surgical debridement of the granuloma using a cold scalpel was performed. Stress urinary incontinence recurred but resolved spontaneously within 1 month. One year later, the patient continues to be asymptomatic.

Delayed resolution of negative pressure pulmonary edema associated with low-molecular-weight dextran after microsurgery--a case report

Negative pressure pulmonary edema (NPPE) is an uncommon perioperative complication after total or partial upper airway obstruction during anesthesia or respiratory distress. The cardinal event causative of the pathophysiology is believed to be the generation of a sudden and marked negative intrapleural pressure against a closed glottis, resulting in a disruption of the normal intravascular Starling mechanism. Ultimately, excessive intravascular fluid which transudes into the interstitial space eventuates in pulmonary edema. In most reports, patients suffering from NPPE could recover within 24 h after appropriate treatment. Here, we report a case of highly suspected NPPE with delayed resolution associated with the perioperative use of dextran, following microsurgery for digital anastomosis of the nearly amputated right thumb. We have reviewed the possible pathomechanisms of NPPE, and discuss herein the possible relationship between the delayed resolution of NPPE and perioperative use of dextran.

Comparison of three fluid solutions for resuscitation in dengue shock syndrome

BACKGROUND

Dengue shock syndrome is characterized by severe vascular leakage and disordered hemostasis and progresses to death in 1 to 5 percent of cases. Although volume replacement is recognized as the critical therapeutic intervention, World Health Organization management guidelines remain empirical rather than evidence-based.

METHODS

We performed a double-blind, randomized comparison of three fluids for initial resuscitation of Vietnamese children with dengue shock syndrome. We randomly assigned 383 children with moderately severe shock to receive Ringer's lactate, 6 percent dextran 70 (a colloid), or 6 percent hydroxyethyl starch (a colloid) and 129 children with severe shock to receive one of the colloids. The primary outcome measure was requirement for rescue colloid at any time after administration of the study fluid.

RESULTS

Only one patient died (<0.2 percent mortality). The primary outcome measure--requirement for rescue colloid--was similar for the different fluids in the two severity groups. The relative risk of requirement for rescue colloid was 1.08 (95 percent confidence interval, 0.78 to 1.47; P=0.65) among children with moderate shock who received Ringer's lactate as compared with either of the colloid solutions, 1.13 (95 percent confidence interval, 0.74 to 1.74; P=0.59) among children who received dextran as compared with starch in the group with severe shock, and 0.88 (95 percent confidence interval, 0.66 to 1.17; P=0.38) among children who received dextran as compared with starch in the combined analysis. Although treatment with Ringer's lactate resulted in less rapid improvement in the hematocrit and a marginally longer time to initial recovery than did treatment with either of the colloid solutions, there were no differences in all other measures of treatment response. Only minor differences in efficacy were detected between the two colloids, but significantly more recipients of dextran than of starch had adverse reactions. Bleeding manifestations, coagulation derangements, and severity of fluid overload were similar for all fluid-treatment groups.

CONCLUSIONS

Initial resuscitation with Ringer's lactate is indicated for children with moderately severe dengue shock syndrome. Dextran 70 and 6 percent hydroxyethyl starch perform similarly in children with severe shock, but given the adverse reactions associated with the use of dextran, starch may be preferable for this group.

Biocatalytic synthesis of highly ordered degradable dextran-based hydrogels

We have prepared unique macroporous and ordered dextran-based hydrogels using a single-step biocatalytic transesterification reaction between dextran and divinyladipate in neat dimethylsulfoxide. These hydrogels show a unimodal distribution of interconnected pores with average diameters from 0.4 to 2.0 microm depending on the degree of substitution. In addition, the hydrogels show a higher elastic modulus for a given swelling ratio than chemically synthesized dextran-based hydrogels. In vivo studies in rats show that the hydrogel networks are degradable over a range of time scales from 5 to over 40 days, and possess good biocompatibility, as reflected in only a mild inflammatory reaction and minor fibrous capsule formation during the time-frame of subcutaneous implantation. These combined properties may offer competitive advantages in biomedical applications ranging from tissue engineering to controlled drug delivery.

Tissue reactions of in situ formed dextran hydrogels crosslinked by stereocomplex formation after subcutaneous implantation in rats

In this study, the in vivo biocompatibility of physically crosslinked dextran hydrogels was investigated. These hydrogels were obtained by mixing aqueous solutions of dextran grafted with L-lactic acid oligomers and dextran grafted with D-lactic acid oligomers. Gelation occurs due to stereocomplex formation of the lactic acid oligomers of opposite chirality. Since gelation takes some time, in situ gel formation is possible with this system. A number of sterilization methods was evaluated for their effect on the chemical and physical properties of the hydrogel. It was shown that of the investigated options (filtration, gamma irradiation, dry-heat and autoclaving) dry-heat sterilization was the preferred method to prepare sterile gels suitable for in vivo evaluations. Two types of stereocomplex gels were prepared and implanted subcutaneously in rats. The tissue reaction was evaluated over a period of 30 days. A mild ongoing foreign body reaction was observed characterized by infiltration of macrophages. Giant cells were only scarcely formed and the low numbers of lymphocytes showed that priming of the immune system is hardly involved. Importantly, the gels fully degraded in vivo within 15 days, which is in good agreement with the in vitro degradation behaviour of these gels. In conclusion, stereocomplexed dextran-oligolactic gels showed good biocompatibility which makes them suitable candidates for the design of controlled release devices for pharmaceutically active proteins.

Small volume hypertonic resuscitation of circulatory shock

Small volume hypertonic resuscitation is a relatively new conceptual approach to shock therapy. It was originally based on the idea that a relatively large blood volume expansion could be obtained by administering a relatively small volume of fluid, taking advantage of osmosis. It was soon realized that the physiological vasodilator property of hypertonicity was a useful byproduct of small volume resuscitation in that it induced reperfusion of previously ischemic territories, even though such an effect encroached upon the malefic effects of the ischemia-reperfusion process. Subsequent research disclosed a number of previously unsuspected properties of hypertonic resuscitation, amongst them the correction of endothelial and red cell edema with significant consequences in terms of capillary blood flow. A whole set of actions of hypertonicity upon the immune system are being gradually uncovered, but the full implication of these observations with regard to the clinical scenario are still under study. Small volume resuscitation for shock is in current clinical use in some parts of the world, in spite of objections raised concerning its safety under conditions of uncontrolled bleeding. These objections stem mainly from experimental studies, but there are few signs that they may be of real clinical significance. This review attempts to cover the earlier and the more recent developments in this field.

Effect of hypertonic saline dextran on acid-base balance in patients undergoing surgery of abdominal aortic aneurysm*

OBJECTIVE

To evaluate the magnitude and cause of metabolic acidosis after infusion of 7.5% sodium chloride 6% dextran 70.

DESIGN

Randomized, prospective clinical study.

SETTING

University hospital.

PATIENTS

Two groups of 14 patients each, undergoing repair of abdominal aortic aneurysm.

INTERVENTIONS

Patients were randomly assigned to receive either 250 mL of hypertonic saline dextran (HSD) or a conventional fluid regimen with 250 mL of hydroxyethyl starch in normal saline solution (H-NS) during the period of aortic clamping. Additionally, normal saline was used in both groups to reach a target pulmonary artery occlusion pressure of 15-18 mmHg. pH, Paco2, and serum concentrations of sodium, potassium, magnesium, calcium, chloride, lactate, albumin, and phosphate were measured. Strong ion difference was calculated as (sodium + potassium + magnesium + calcium) - (chloride + lactate). The amount of weak plasma acid was calculated.

MEASUREMENTS AND MAIN RESULTS

The infusion of HSD resulted in an immediate large increase in serum sodium (19 mmol/L) and chloride (22 mmol/L), whereas the infusion of H-NS led only to mild increases in serum sodium (3 mmol/L) and chloride (6 mmol/L). Both HSD and H-NS caused concomitant and equal decreases in the amount of weak plasma acid, strong ion difference, and pH (7.28-7.30). The reduction of bicarbonate was also identical and proportional to the extent of dilution due to infusion of HSD and H-NS. This induced metabolic acidosis was corrected spontaneously in both groups 24 hrs after surgery.

CONCLUSION

Both the intravenous administration of 7.5% sodium chloride and the conventional fluid regimen with saline-based 6% hydroxyethyl starch solution resulted in a metabolic acidosis of equal extent. This suggests dilution of plasma buffers or a decrease in strong ion difference to be the primary cause of metabolic acidosis.

Thrombelastographic whole blood clot formation after ex vivo addition of plasma substitutes: improvements of the induced coagulopathy with fibrinogen concentrate

BACKGROUND

Plasma substitutes such as hydroxyethyl starch (HES) and various dextrans may compromise the haemostatic system, thereby causing potentially dangerous bleeding. Whilst several mechanisms have been advanced to explain the nature of the coagulopathy induced by this colloid, there has been comparably little interest in devising ways to optimize haemostasis after a relative colloid overdose.

METHODS

Real-time whole blood (WB) clot formation profiles were recorded using a thrombelastographic method employing activation with tissue factor. The coagulation tracings were transformed into dynamic velocity profiles of WB clot formation. WB from healthy individuals (n=20) was exposed to haemodilution of approximately 55% with isotonic saline, HES 200/0.5, HES 130/0.4, and dextran 70, respectively. Possible modalities for improvement of the induced coagulopathy were explored, in particular ex vivo addition of a fibrinogen concentrate.

RESULTS

WB coagulation profiles changed significantly with decreased clot strength, and a compromised propagation phase of clot formation. The duration of the initiation phase of WB coagulation was unchanged. No statistical differences were detected amongst the HES solutions and dextran 70. However, dextran 70 returned a more suppressed clot development and strength compared with the HES solutions. Ex vivo haemostatic addition of washed platelets (75 x 10(9) litre(-1)) and factor VIII (0.6 IU ml(-1)) produced insignificant changes in clot initiation, propagation, and in the clot strength. In contrast, ex vivo addition of a fibrinogen concentrate (1 g litre(-1)) improved the coagulopathy induced by all of the three individual plasma expanders tested.

CONCLUSION

Coagulopathy induced by haemodilution with either HES 200/0.5, HES 130/0.4, and dextran 70 may be improved by fibrinogen supplementation.