The Use of Hemostatic Agents and Sealants in Urology

John J, Khademhosseini A. Recent advances in biopolymer-based hemostatic materials

Hemorrhage is the leading cause of trauma-related deaths, in hospital and prehospital settings. Hemostasis is a complex mechanism that involves a cascade of clotting factors and proteins that result in the formation of a strong clot. In certain surgical and emergency situations, hemostatic agents are needed to achieve faster blood coagulation to prevent the patient from experiencing a severe hemorrhagic shock. Therefore, it is critical to consider appropriate materials and designs for hemostatic agents. Many materials have been fabricated as hemostatic agents, including synthetic and naturally derived polymers. Compared to synthetic polymers, natural polymers or biopolymers, which include polysaccharides and polypeptides, have greater biocompatibility, biodegradability and processibility. Thus, in this review, we focus on biopolymer-based hemostatic agents of different forms, such as powder, particles, sponges and hydrogels. Finally, we discuss biopolymer-based hemostatic materials currently in clinical trials and offer insight into next-generation hemostats for clinical translation.

Hemostatic efficacy of two topical adjunctive hemostats in a porcine spleen biopsy punch model of moderate bleeding

Topical hemostatic agents have become essential tools to aid in preventing excessive bleeding in surgical or emergency settings and to mitigate the associated risks of serious complications. In the present study, we compared the hemostatic efficacy of SURGIFLO^® Hemostatic Matrix Kit with Thrombin (Surgiflo-flowable gelatin matrix plus human thrombin) to HEMOBLAST™ Bellows Hemostatic Agent (Hemoblast-a combination product consisting of collagen, chondroitin sulfate, and human thrombin). Surgiflo and Hemoblast were randomly tested in experimentally induced bleeding lesions on the spleens of four pigs. Primary endpoints included hemostatic efficacy measured by absolute time to hemostasis (TTH) within 5 min. Secondary endpoints included the number of product applications and the percent of product needed from each device to achieve hemostasis. Surgiflo demonstrated significantly higher hemostatic efficacy and lower TTH (p < 0.01) than Hemoblast. Surgiflo-treated lesion sites achieved hemostasis in 77.4% of cases following a single product application vs. 3.3% of Hemoblast-treated sites. On average, Surgiflo-treated sites required 63% less product applications than Hemoblast-treated sites (1.26 ± 0.0.51 vs. 3.37 ± 1.16). Surgiflo provided more effective and faster hemostasis than Hemoblast. Since both products contain thrombin to activate endogenous fibrinogen and accelerate clot formation, the superior hemostatic efficacy of Surgiflo in the porcine spleen punch biopsy model seems to be due to Surgiflo's property as a malleable barrier able to adjust to defect topography and to provide an environment for platelets to adhere and aggregate. Surgiflo combines a flowable gelatin matrix and a delivery system well-suited for precise application to bleeding sites where other methods of hemostasis may be impractical or ineffective.

Use of hemostatic agents for surgical bleeding in laparoscopic partial nephrectomy: Biomaterials perspective

In recent years, there was an abrupt increase in the incidence of renal tumors, which prompt up the appearance of cutting-edge technology, including minimally invasive and organ-preserving approaches, such as laparoscopic partial nephrectomy (LPN). LPN is an innovative technique used to treat small renal masses that have been gaining popularity in the last few decades due to its promissory results. However, the bleeding control remains the main challenge since the majority of currently available hemostatic agents (HAs) used in other surgical specialities are inefficient in LPN. This hurried the search for effective HAs adapted for LPN surgical peculiarities, which resulted on the emergence of different types of topical HAs. The most promising are the natural origin HAs because of their inherent biodegradability, biocompatibility, and lowest toxicity. These properties turn them top interests' candidates as HAs in LPN. In this review, we present a deep overview on the progress achieved in the design of HAs based on natural origin polymers, highlighting their distinguishable characteristics and providing a clear understanding of their hemostat's role in LPN. This way it may be possible to establish a structure-composition properties relation, so that novel HAs for LPN can be designed to explore current unmet medical needs.

An update on oxidized regenerated cellulose (fibrillar™) in reducing postoperative corporal bleeding following inflatable penile prosthesis surgery

Background

Scrotal hematoma formation is a dreaded complication of penile prosthesis surgery that increases patient pain and healthcare costs, as well the risk for eventual device infection and failure. The efficacy of hemostatic agents in reducing the incidence of scrotal hematoma development has not been extensively studied in urologic prosthetic surgery. In this paper we further evaluate our experience with oxidized regenerated cellulose (ORC; Surgicel Fibrillar™) as an adjunct to standard hemostatic practices in inflatable penile prosthesis (IPP) implantation.

Methods

From April 2016 onward, intracorporal ORC pledgets were placed during corporotomy closure in all patients undergoing IPP implantation or revision by a single surgeon using an identical surgical technique. Perioperative parameters and outcomes-primarily postoperative cumulative drain output, secondarily patient phone calls in the postoperative period-were compared among successive cases with ORC (April 2016 to February 2019) and without ORC (April 2013 to March 2016).

Results

A total of 274 men underwent IPP implantation during the study period; 175 (64%) had ORC included in their corporotomy closures. Median drain output was significantly reduced in the ORC patients relative to the non-ORC group (50 vs. 65 mL; P=0.0001). A significant reduction in patient-initiated phone calls regarding scrotal pain, swelling, or discomfort in the first 4 weeks following surgery was also observed in the ORC group (average 0.69 vs. 1.1 calls per patient; P=0.03). A total of 9 patients underwent IPP explantation during the study period, all due to device infection; 5 of these were in the ORC group, while 4 were in the non-ORC group (P=0.73). ORC use did not constitute any additional infection risk.

Conclusions

Bilateral incorporation of ORC pledgets during corporotomy closure in IPP surgery significantly decreases postoperative scrotal drain output, a well-documented risk factor for scrotal hematoma formation.

Hemostatic effect and psychological impact of an oxidized regenerated cellulose patch after transrectal ultrasound-guided prostate biopsy: A prospective and retrospective study

To investigate the usefulness of the oxidized regenerated cellulose patch (ORCP) for postbiopsy hemostasis, anxiety, and depression in patients undergoing transrectal ultrasound-guided prostate biopsy.This was a prospective-retrospective study of 300 patients who underwent systematic 12-core prostate biopsy from August 2016 through March 2018. The ORCP was inserted into the rectum immediately after prostate biopsy in the prospective group (n = 150), while the retrospective group (n = 150) underwent prostate biopsy alone. The frequency rate and duration of hematuria, rectal bleeding, and hematospermia were compared between the 2 groups. Anxiety and depression were assessed with the hospital anxiety and depression scale before and after prostate biopsy in the prospective group.The frequency rates of hematuria and hematospermia showed no significant differences between the prospective versus retrospective groups (64.7% vs 66.7%, P = .881; 18 vs 20%, P = .718; respectively). Frequency of rectal bleeding was significantly lower in the prospective group than in the retrospective group (26.7% vs 42.7%, P = .018). However, there were no significant differences in median duration of rectal bleeding, hematuria, or hematospermia between the 2 groups (2, 5, and 2 days vs 2, 7, and 1 day, P > .05, respectively, for the prospective vs retrospective group). Multivariate analysis found that ORCP insertion was a significant protective factor against postbiopsy rectal bleeding (P = .038, odds ratio 0.52). Only anxiety level in the prospective group before versus after prostate biopsy was significantly reduced (5 vs 4, P = .011).ORCP insertion after prostate biopsy is an effective and simple method for decreasing rectal bleeding. ORCP insertion may also alleviate anxiety in patients undergoing prostate biopsy.

The effect of the new hemostatic agent Ostene® on bone healing: An experimental study in rabbits

Introduction: Ostene® is a water-soluble wax-like alkylene oxide copolymer preparation for use as a mechanical hemostatic agent. This study aims to evaluate the effects of Ostene® on bone healing. Materials and Methods: Twenty albino rabbits were divided into four groups according to post-treatment follow-up (24 hr, 3 days, 7 days, 14 days) with five rabbits in each group. Each rabbit in all groups was treated with two study materials (Ostene® and Gelfoam®). Three holes were made in the mandibular bone of each rabbit using 5mm surgical bur; two holes were made on right side: one for testing Ostene® and another for Gelfoam®. A third hole, on the left side of mandible, was not treated, and was used as a control. Finally, the incision was closed. The specimens were collected at different days post-treatment and examined by histopathology. Result and Discussion: This study showed that there is a significant difference (p-value≤ 0.05) between the Ostene® group and the other groups (Gelfoam® and control). At 24 hr post intervention, there is a significant difference in osteoblast cell formation (p-value=0.03), and osteoclast cell formation (p-value=0.05). New blood vessel formation, osteoblast and osteoclast cell formation for Ostene® group at 3 days post-intervention were also significantly different (p-values = 0.05, 0.03, 0.04, respectively). At 7 days post-intervention p-values were 0.05 for osteoblast formation and 0.04 for osteoclast formation, respectively. After 14 days of healing p-value for osteoblast cell formation in the Ostene® group was 0.05 and 0.04 for osteoclast cell formation. Conclusions: The bone hemostatic agent Ostene® is an effective at enhancing osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Practical Suggestions for Prevention of Complications Arising from Oxidized Cellulose Retention: A Case Report and Review of the Literature

BACKGROUND Bleeding is a major intraoperative complication during surgical procedures. When conventional methods such as ligature and diathermocoagulation are ineffective for bleeding management, hemostatic agents should be used. Oxidized cellulose is one of the major hemostatic agents used worldwide. Oxidized cellulose is often left in situ after hemostasis because of its high level of reabsorption that lasts up to 8 weeks. However, 38 cases of retaining-associated complications are reported in the literature. CASE REPORT A 51-year-old male patient presented in our emergency department with acute abdominal pain, nausea, and vomiting. The patient had been admitted in our department for laparoscopic cholecystectomy for acute cholecystitis 25 months previously. Abdominal ultrasound and CT scan showed the presence of a cystic circular mass, with homogeneous fluid content, close to the surgical clips of the previous surgery, resembling a "neogallbladder". Laparoscopic abdominal exploration and drainage were performed. Histological examination reported protein-based amorphous material with rare lymphocytes and macrophages. Culturing was negative for bacterial growth. The patient was discharged uneventfully on the 4 th postoperative day. The primary surgical report was evaluated with evidence of application of Gelita-Cel ® Standard for hemostatic purposes. Results of 12-month follow-up were normal. CONCLUSIONS Herein, we report the first case of a complication associated with the use of Gelita-Cel ® Standard. We reviewed the literature to better define the purpose and limits of oxidized cellulose use as a hemostatic agent. Despite the fundamental role of oxidized cellulose as a hemostatic agent, we provide some practical suggestions to prevent the reported severe complications and surgical overtreatments.

Use of oxidized regenerated cellulose to achieve hemostasis during laparoscopic cholecystectomy: a retrospective cohort analysis

OBJECTIVE

Laparoscopic cholecystectomy is the first-choice treatment for symptomatic cholelithiasis. Though generally safe, this procedure is not without complications, with bleeding the most frequent cause of conversion to open cholecystectomy. Oxidized regenerated cellulose (ORC) added to conventional hemostatic strategies, is widely used to control bleeding during surgery despite limited evidence supporting its use. This retrospective study analyzed patients undergoing laparoscopic cholecystectomy in an Italian center over a 16-month period, between October 2014 and February 2016, who experienced uncontrollable bleeding despite the use of conventional hemostatic strategies, requiring the addition of ORC gauze (Emosist®).

RESULTS

Of the 530 patients who underwent laparoscopic cholecystectomy, 24 (4.5%) had uncontrollable bleeding from the liver bed. Of these, 62.5% had acute cholecystitis and 33.3% chronic cholecystitis; 1 patient was diagnosed with gallbladder carcinoma, postoperatively. Most patients had comorbidities, 16.7% had liver cirrhosis, and 37.5% used oral anticoagulants. The application of ORC rapidly controlled bleeding in all patients. Patients were discharged after a mean duration of 2.2 days. ORC was easy to use and well tolerated. Bleeding complications remain a relevant issue in laparoscopic cholecystectomy. ORC was able to promptly stop bleeding not adequately controlled by conventional methods and appears, therefore, to be a useful hemostat.

Absorbable Hemostatic Aggregates

Topical absorbable hemostats are routinely utilized in surgical procedures to assist in controlling intraoperative bleeding. SURGICEL Original Absorbable Hemostat, one of the most frequently used adjunctive hemostats, is composed of oxidized regenerated cellulose (ORC). We report here that a novel powdered form of ORC, composed of aggregates of ORC fine fibers, provides additional valuable hemostatic performance characteristics and retains the biochemical and bactericidal profile of the parent ORC fabric. The ORC aggregates are more effective in promoting coagulation than their constituent ORC fine fibers because of more favorable surface energetics and surface area. Aggregates with similar particle size distributions that have higher sphericity values exhibit better coagulation efficacy. Finally, ORC aggregates more effectively promote clot formation than starch-based hemostatic particles. The results of this investigation indicate that the efficacy of this novel powdered hemostat is based on its chemical composition, morphology, and particle surface energetics.

Oxidized Regenerated Cellulose (Fibrillar) Reduces Risk of Postoperative Corporal Bleeding Following Inflatable Penile Prosthesis Surgery

OBJECTIVE

To report our initial experience with oxidized regenerated cellulose (ORC; Surgicel Fibrillar) as a hemostatic adjunct during inflatable penile prosthesis (IPP) surgery.

MATERIALS AND METHODS

Beginning in April 2016, ORC pledgets were placed within the corporotomy closures of all men undergoing IPP insertion. Perioperative characteristics and outcomes including cumulative postoperative drain output were evaluated among consecutive cases with (April 2016 to October 2016) and without ORC (December 2015 to March 2016) using an identical surgical technique by a single surgeon.

RESULTS

During the study period, 64 men underwent IPP implantation, of whom 32 (50%) received ORC. There was a significant reduction in median drain output relative to controls (33 mL vs 65 mL; P = .01). Postoperatively, ORC use was associated with a reduction in the number of patient phone calls for scrotal-related concerns in the immediate postoperative period (average 0.5 vs 1.1; P = .03). There were 3 IPP explantations in the non-ORC group (2/3 for infection)-one of which was directly related to an infected hematoma. After controlling for other clinical features, the use of ORC (β -32, 95% confidence interval: -61 to -5; P = .02) was independently associated with a reduction in drain output.

CONCLUSION

ORC use during IPP corporotomy closure reduces postoperative drain output, a known risk factor for hematoma-related complications.

Hemostatic agents used for nephrostomy tract closure after tubeless PCNL: a systematic review and meta-analysis

To evaluate the role of hemostatic agents used for nephrostomy tract closure after tubeless percutaneous nephrolithotomy (PCNL). A systematic review of Pubmed, Embase and Cochrane was performed. All studies that compared hemostatic agents with common methods (silk stitch or pressure dressing) were included. The analyzed outcomes were hospital stay, operative time, blood loss, transfusion rate, fever rate, and complication rate. A total of eight articles including six RCTs met our criteria. Hemostatic agents showed short hospital stay (MD -4.54, 95 % CI -6.78 to -2.36, p < 0.0001). There was no difference between hemostatic agents and common methods on operative time (MD 2.00, 95 % CI -17.32 to 21.33, p = 0.84), blood loss (MD -0.19, 95 % CI -0.41 to 0.03, p = 0.08), transfusion rate (OR 1.42, 95 % CI 0.34-5.96, p = 0.63), fever rate (OR 1.02, 95 % CI 0.33-3.12, p = 0.97) and complication rate (OR 1.02, 95 % CI 0.33-3.12, p = 0.97). Eight studies including six RCTs showed that use of hemostatic agents was safe. Hemostatic agents showed short hospital stay. There were no difference between hemostatic agents and common methods on blood loss, transfusion rate, fever rate, and complication rate.

Systematic review and meta-analysis of fibrin sealants for patients undergoing pancreatic resection

INTRODUCTION

Post-operative pancreatic fistula (POPF) is a common complication after partial pancreatic resection, and is associated with increased rates of sepsis, mortality and costs. The role of fibrin sealants in decreasing the risk of POPF remains debatable. The aim of this study was to evaluate the literature regarding the effectiveness of fibrin sealants in pancreatic surgery.

METHODS

A comprehensive database search was conducted. Only randomized controlled trials comparing fibrin sealants with standard care were included. A meta-analysis regarding POPF, intra-abdominal collections, post-operative haemorrhage, pancreatitis and wound infections was performed according to the recommendations of the Cochrane collaboration.

RESULTS

Seven studies were included, accounting for 897 patients. Compared with controls, patients receiving fibrin sealants had a pooled odds ratio (OR) of developing a POPF of 0.83 [95% confidence interval (CI): 0.6-1.14], P = 0.245. There was a trend towards a reduction in post-operative haemorrhage (OR = 0.43 (95%CI: 0.18-1.0), P = 0.05) and intra-abdominal collections (OR = 0.52 (95%CI: 0.25-1.06), P = 0.073) in those patients receiving fibrin sealants. No difference was observed in terms of mortality, wound infections, re-interventions or hospital stay.

CONCLUSION

On the basis of these results, fibrin sealants cannot be recommended for routine clinical use in the setting of pancreatic resection.

Patterns of use of hemostatic agents in patients undergoing major surgery

BACKGROUND

Although a number of prohemostatic agents that are applied intraoperatively have been introduced to minimize bleeding, little is known about the patterns of use and the factors that influence use. We examined the use of hemostatic agents in patients undergoing major surgery.

METHODS

All patients who underwent major general, gynecologic, urologic, cardiothoracic, or orthopedic surgery from 2000-2010 who were recorded in the Perspective database were analyzed.

RESULTS

Among 3,633,799 patients, hemostatic agents were used in 30.3% (n = 1,102,267). The use of hemostatic agents increased from 28.5% in 2000 to 35.2% in 2010. Over the same period, the rates of transfusion declined for pancreatectomy (-14.4%), liver resection (-15.0%), gastrectomy (-11.7%), prostatectomy (-6.6%), nephrectomy (-4.6%), hip arthroplasty (-10.4%), and knee arthroplasty (-6.6%). Over the same time period, the transfusion rate increased for colectomy (6.0%), hysterectomy (3.7%), coronary artery bypass graft (8.4%), valvuloplasty (4.2%), lung resection (1.9%), and spine surgery (1.6%). Transfusion remained relatively stable for thyroidectomy (0.2%).

CONCLUSIONS

The use of hemostatic agents has increased rapidly even for surgeries associated with a small risk of transfusion and bleeding complications. In addition to patient characteristics, surgeon and hospital factors exerted substantial influence on the allocation of hemostatic agents.

Evaluation of a gelatin matrix as a topical hemostatic agent for hepatic bleeding in the dog

New generation topical hemostatic agents containing thrombin have been developed for use in surgical procedures when control of bleeding by conventional methods is either ineffective or impractical. The authors compared the safety, hemostatic efficacy, and handling characteristics of a thrombin-containing topical surgical hemostatic agent (a gelatin matrix) to a hemostatic gelatin sponge for treatment of parenchymal bleeding after liver biopsy. Fourteen dogs were enrolled in this prospective clinical study. Paired 1.5 cm × 1.5 cm and 0.5 cm deep liver biopsies were obtained via laparotomy for each dog. One bleeding liver biopsy lesion was treated with the gelatin matrix and the other with a gelatin sponge. The treated liver biopsy sites were compared for bleeding severity, time to hemostasis, cumulative blood loss, and hemostatic agent handling characteristics. Median time to hemostasis was significantly shorter (P = 0.034) and median cumulative blood loss was significantly lower (P = 0.033) for the lesions treated with the gelatin matrix than the gelatin sponge. Adverse reactions were not observed within the first 24 hr postoperatively. When used to control parenchymal bleeding from liver biopsy sites in the dog, the evaluated gelatin matrix was safe and more effective than the gelatin sponge.

The use of Tachosil as hemostatic sealant in nephron sparing surgery for Wilms tumor: preliminary observations

BACKGROUND

TachoSil, which is an absorbable collagen sponge coated with human fibrinogen and thrombin, has proven to enhance hemostasis and promote optimal wound healing in adults undergoing nephron sparing surgery (NSS). We report our preliminary experience using this hemostatic agent during NSS in children.

METHODS

Prospective analysis of 3 patients with Wilms tumor (synchronous bilateral in one) undergoing NSS at our institution over an 18-month period. Primary outcome measures were intraoperative bleeding control and surgery-related postoperative sequelae.

RESULTS

Overall, 4 kidneys underwent 5 NSS procedures, which included 3 partial nephrectomies and multiple tumor excisions performed on another kidney at initial and second-look surgery. After control of major bleeding and suturing of the collecting system, which was entered during 2 of the 5 NSS procedures, TachoSil was applied to the parenchymal surface of the kidney, achieving immediate hemostasis. All NSS procedures were performed without hilar clamping, drainage or stent placement. None of the patients required blood transfusion. Small perirenal fluid collections were documented postoperatively, and all spontaneously resolved within 4 weeks of surgery.

CONCLUSION

In children undergoing NSS, TachoSil represents an effective and safe tool for control of mild to moderate bleeding, and also facilitates sealing and wound dressing.

Comparative analysis of periprostatic implantation and intracavernosal injection of human adipose tissue-derived stem cells for erectile function recovery in a rat model of cavernous nerve injury

BACKGROUND

We compared periprostatic implantation (PPI) and intracavernosal injection (ICI) of human adipose tissue-derived stem cell (ADSC) to facilitate recovery of erectile function in a rat model of cavernous nerve (CN) injury.

METHODS

Bilateral CN dissection (BCND) was induced in Sprague-Dawley rats. After BCND 10 rats each were treated with PPI and/or ICI of ADSCs. After 4 weeks erectile responses to electric pelvic ganglion stimulation were studied. Each penis was evaluated in terms of the expression of neuronal nitric oxide synthase and smooth muscle content.

RESULTS

The ratio of maximal intracavernosal pressure to mean arterial pressure was significantly decreased in the BCND group (24.5%) compared to the sham group (64.2%). PPI and ICI significantly improved erectile function (46.7% and 47.9%, respectively) compared to the BCND group. A combination of PPI and ICI (42.5%) did not afford any incremental effect on erectile function. After stem cell therapy, the expression of neuronal nitric oxide synthase increased slightly in the ICI group without statistical relevance, whereas the PPI and combination groups showed marginally significant increases (P = 0.08). In both the PPI and ICI groups, the smooth muscle content was similar to the sham group. The combination group showed remarkable increase in smooth muscle content to an extent greater than that seen when either treatment was given alone, although statistically not significant.

CONCLUSION

PPI or ICI of ADSCs in a rat model of CN injury were equally effective in recovering penile erection, but may address different types of pathophysiology.

Efficacy of BloodSTOP iX, surgicel, and gelfoam in rat models of active bleeding from partial nephrectomy and aortic needle injury

OBJECTIVE

To compare the bleeding time using 3 different hemostatic agents in a rat model of partial nephrectomy and aortic needle injury.

METHODS

Bilateral partial nephrectomy was performed in 20 rats with a total bleeding surface of 1.5 cm(2) without vascular clamping. Surgicel (n = 10) or BloodSTOP iX (n = 10) matrix was applied on each kidney cut surface. Finger pressure was applied to the parenchyma with transparent plastic bubble wrap to allow for visualization of the site and monitor the bleeding time. Pressure was applied until the bleeding stopped and then released to assess the presence of active bleeding for 5 minutes. An additional 24 rats underwent aortic trauma with a 25-gauge needle puncture, and the efficacy of the topical hemostatic agents were compared among Gelfoam (n = 8), Surgicel (n = 8), and BloodSTOP iX (n = 8).

RESULTS

After partial nephrectomy, the mean bleeding time with BloodSTOP iX and Surgicel treatment was 83.70 ± 13.73 seconds and 168.8 ± 19.41 seconds, respectively, a statistically significant difference (P = .002). After aortic injury, the mean bleeding time was 157.5 ± 31.44 seconds, 187.5 ± 23.20 seconds, and 66.00 ± 13.74 seconds in the Gelfoam, Surgicel, and BloodSTOP groups, respectively, which was statistically significant (P = .004).

CONCLUSION

The BloodSTOP iX hemostatic surgical matrix was more effective in reducing the bleeding time than Surgicel in a rat model of partial nephrectomy. Similarly, in an aortic needle injury model, BloodSTOP iX achieved hemostasis faster than Gelfoam or Surgicel.

In vivo hemostatic efficacy of polyurethane foam compared to collagen and gelatin

OBJECTIVES

Topical hemostatic agents are used in all surgical disciplines. Most of these hemostats are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission. A newly developed biodegradable, fully synthetic hemostatic agent based on polyurethane foam (PU) with 55 % polyethylene glycol (PEG) would prevent these potential risks.

MATERIALS AND METHODS

The hemostatic efficacy of this new agent was compared to gelatin and collagen in humans who underwent extraction of an upper and lower molar (split-mouth model). After extraction of a molar in the maxilla and mandible, a PU foam and collagen or gelatin were inserted in the extraction socket for 2 min. Hereafter, the agents were removed and stored in ethylenediaminetetraacetic acid to stop coagulation. Then, the concentration of coagulation parameters thrombin-antithrombin III (TAT) complexes, fibrinogen, and thromboxane B2 (TxB2) in blood extracts from the agents was measured. The concentrations were also determined in baseline blood samples which were collected from the extraction socket.

RESULTS

The concentrations of TAT and TxB2 were significantly increased, and fibrinogen concentration was significantly reduced compared to baseline wound blood concentrations indicating enhanced hemostasis. No significant differences were seen in the concentrations of these coagulation parameters in the three different hemostatic agents.

CONCLUSIONS

These results show that PU combined with 55 % PEG is a promising alternative for the animal-derived hemostatic agents.

CLINICAL RELEVANCE

The synthetic hemostatic agent could replace the animal-derived products like collagen and gelatin and therewith prevent the potential risk of pathogen transmission.

Local tissue reaction after the application of topical hemostatic agents in a rat partial nephrectomy model

Various hemostatics are used for renal surgical procedures. We investigated the hemostatic efficacy of cellulose derivatives on the model of partial nephrectomy in rats focusing on the local reaction of renal parenchyma. A total of 50 Wistar rats were divided into five groups of 10 animals each. Partial nephrectomy of the caudal pole without hilar vascular control was performed. Oxidized cellulose (OC), sodium salt of oxycellulose (OCN), carboxymethyl cellulose (CMC), dialdehyde cellulose (DAC), and gelatin-based hemostatic (C) were applied to the bleeding wounds. The time to hemostasis was monitored. Half of the animals were euthanized after 3 days, the second half 30 days from the experiment start date. The left kidney was excised and subjected to histopathological examination. The biochemical data was subjected to statistical analysis. The time to hemostasis in all groups was significantly less than in the C group (in OC p = 0.0057, OCN p = 0.0039, CMC and DAC p = 0.0001). In the C group, massive hemorrhages and necrosis did occur. In the OC and OCN groups, there were regenerative changes, a receding inflammatory reaction and hemorrhage. DAC caused an immune reaction and massive interstitial hemorrhages with biochemical signs of liver damage. Parenchyma in CMC revealed a reduction of necrosis and interstitial hemorrhages with regenerative processes. The most effective hemostatics were CMC and OC, achieving the best results both in the time to hemostasis, and for histopathological evaluation.

Oxidized regenerated cellulose granuloma mimicking recurrent mass lesion after laparoscopic nephron sparing surgery

INTRODUCTION

Achieving hemostasis in laparoscopic nephron sparing surgery (LNSS), a technically demanding procedure, is challenging. Absorbable hemostatic agents, such as oxidized regenerated cellulose (ORC) are frequently used for hemostasis in laparoscopic nephron sparing surgery. Retention of this material is a very rare situation.

PRESENTATION OF THE CASE

We are presenting a case of ORC granuloma after nephron sparing surgery for renal cell carcinoma (RCC) mimicking recurrent renal mass. A 50-year-old woman diagnosed with upper pole renal mass underwent laparoscopic nephron sparing surgery. Oxidized regenerated cellulose was used to achieve hemostasis for an oozing from the perirenal tissue. Resection confirmed RCC. Imaging at 6th month follow-up revealed a lesion with contrast enhancement at the location of the adrenal gland. Positron emission tomography suggested inflammation or metastasis. Histopathological evaluation of the mass revealed foreign body granuloma.

DISCUSSION

Laparoscopic nephron sparing surgery is becoming a standardized treatment of select renal tumors. Hemostatic agents, such as ORC, are frequently used to minimize complications in LNSS. In case of ORC application, which is completely absorbed in 8 weeks, to or to a location with close proximity to the primary resection site, surgical granuloma formation should be considered. However its use should not be discouraged and biopsy may be considered for definitive diagnosis.

CONCLUSION

Oxidized regenerated cellulose granuloma may mimic different entities such as including invasive carcinoma. Thus it is of utmost importance, if ORC was used during LNSS, the location and use of this material should be noted precisely.

Safety and efficacy of microporous polysaccharide hemospheres in neurosurgery

BACKGROUND

Effective hemostasis is mandatory for brain tumor surgery. Microporous polysaccharide hemosphere (MPH) powder, a white powder compounded from potato starch, was recently introduced for surgical and emergency application.

OBJECTIVE

To evaluate the safety and efficacy of MPHs in brain tumor surgery.

METHODS

Thirty-three patients (mean age, 58 years; range, 22-84 years) underwent microsurgical brain tumor resection. Final hemostasis was performed by topical application of MPHs, video recorded, and subsequently analyzed. Blood samples were taken before surgery, before application of hemospheres, and postoperatively. Volume measurements of the tumor, resection cavity, and postoperative hematoma were done on magnetic resonance imaging and computed tomography scans. Clinical examinations focused on neurological outcome, complications, and allergic reactions.

RESULTS

Effective hemostasis was achieved by exclusive use of MPHs in 32 patients. In 1 patient, a single arterial bleeding underwent additional bipolar electrocauterization. Mean operative time was 156.8 minutes (range, 60-235 minutes). Hemostasis with MPHs required 57 seconds (mean; range, 8-202 seconds). Subjective neurosurgeons' ranking of the hemostasis effect indicated excellent satisfaction. For the first 3 months, there was no hemospheres-related postoperative neurological worsening, no signs of allergic reaction, and no embolic complications. Early postoperative and 3-month follow-up magnetic resonance imaging and computed tomography scans excluded any expansive bleeding complication. As early as postoperative day 1, MPHs were no longer detected. There was no tumor mimicking contrast enhancement.

CONCLUSION

In neurosurgery, MPHs allow fast and effective minimally invasive hemostasis. In this small case series, no adverse reactions were found.

Single-donor fibrin sealant for repair of urethrocutaneous fistulae following multiple hypospadias and epispadias repairs

PURPOSE

To evaluate the efficacy of fibrin sealant for repair of urethrocutaneous fistula after multiple failed hypospadias and epispadias surgeries.

MATERIALS AND METHODS

The study population comprised 11 boys (mean age 12.18 years) with history of hypospadias or epispadias and at least two failed fistula repair operations leading to recurrent urethrocutaneous fistula. During the operation, single-donor fibrin glue, either from the patient (7) or a parent (4), was applied over the suture lines and beneath the skin. A urethral catheter was kept in place for 7-10 days. Follow up ranged from 6 to 24 months (mean 12.63 months).

RESULTS

Nine patients had an uneventful postoperative course. In one patient with a large fistula, partial wound dehiscence occurred. In another patient with complete hypospadias, hematoma formation caused skin dehiscence but the urethra remained intact. Both cases recovered after 6 months with no further intervention. No fistula recurrence was reported during follow up.

CONCLUSION

Single-donor fibrin glue could be a useful adjunct to surgical management of patients after multiple failed attempts at hypospadias or epispadias fistula repair. Moreover, this product improves the safety margin regarding the risk of disease transmission.

Evolution of hemostatic agents in surgical practice

Objective:

Topical hemostatic agents are used in a wide variety of surgical settings, and the evolution of this class of surgical tools is an interesting topic. We reviewed and outlined the historical progress of topical hemostats into present day surgery and urology, and highlight opportunities for future research.

Materials and Methods:

A MEDLINE search of all available literature concerning several classes of topical hemostatic agents was performed. Fibrins sealants, Gelatin sponge hemostatics, cyanoacrylate adhesives, oxidized regenerated cellulose, and microfibrillar collagen were included. References were chosen from a broad range of surgical literature.

Results:

Topical hemostatic agents have historically taken advantage of a wide variety of mechanisms for hemostasis. Fibrin sealants have a rich history and large potential for further applications. Gelatin sponge hemostatics have been widely used since their introduction, but have changed little. Cyanoacrylate adhesives have a unique mechanism and opportunity for novel applications of existing products. Oxidized cellulose was original in the use of plant-based components. Microfibrillar collagen hemostats have evolved to a wide variety of formats.

Conclusions:

A review of the evolution of topical hemostatic agents highlights opportunities for potential novel research. Fibrin sealants may have the most opportunity for advancement, and understanding the history of these products is useful. With the drive in urology for minimally invasive surgical techniques, adaptation of topical hemostatic agents to this surgical approach would be valuable and offers an opportunity for novel contributions.

New instrumentation in percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is the procedure of choice for removing large, complex, and/or multiple renal calculi. Since its first description in 1976, PCNL techniques and equipment have evolved to maximize procedural efficacy, safety, and reproducibility. We reviewed current literature from January 2004 to November 2009 using Medline search regarding PCNL instrumentation and technology. Additional equipment discovered during the review process without published Medline evidence was summarized from manufacturer brochures and data. Included in this review are summaries of intracorporeal lithotriptors and accessory equipment, stone manipulation devices, PCNL tract sealants, and a digital rigid nephroscope. The evolution of these devices from their predecessors has increased the instrumentation options for the treating urologist and may represent more effective technology for the percutaneous treatment of large renal stones.

Evolution of hemostatic agents in surgical practice

OBJECTIVE

Topical hemostatic agents are used in a wide variety of surgical settings, and the evolution of this class of surgical tools is an interesting topic. We reviewed and outlined the historical progress of topical hemostats into present day surgery and urology, and highlight opportunities for future research.

MATERIALS AND METHODS

A MEDLINE search of all available literature concerning several classes of topical hemostatic agents was performed. Fibrins sealants, Gelatin sponge hemostatics, cyanoacrylate adhesives, oxidized regenerated cellulose, and microfibrillar collagen were included. References were chosen from a broad range of surgical literature.

RESULTS

Topical hemostatic agents have historically taken advantage of a wide variety of mechanisms for hemostasis. Fibrin sealants have a rich history and large potential for further applications. Gelatin sponge hemostatics have been widely used since their introduction, but have changed little. Cyanoacrylate adhesives have a unique mechanism and opportunity for novel applications of existing products. Oxidized cellulose was original in the use of plant-based components. Microfibrillar collagen hemostats have evolved to a wide variety of formats.

CONCLUSIONS

A review of the evolution of topical hemostatic agents highlights opportunities for potential novel research. Fibrin sealants may have the most opportunity for advancement, and understanding the history of these products is useful. With the drive in urology for minimally invasive surgical techniques, adaptation of topical hemostatic agents to this surgical approach would be valuable and offers an opportunity for novel contributions.

The use of adjunctive hemostatic agents for tubeless percutaneous nephrolithotomy

Tubeless percutaneous nephrolithotomy (PCNL) is a viable option for selected patients, particularly those with solitary calculi, multiple stones located in a single location, or those that can be accessed using one access tract. Benefits over the standard PCNL include reduced hospital stay, decreased pain, and decreased urine leak from the access site that would typically occur from around the nephrostomy tube. Hemostatic agents in the form of fibrin "glue" or gelatin matrix substances have been demonstrated to be safe and effective to augment the tubeless procedure. The most appropriate sealant agent available is yet to be determined. We present a review of the contemporary literature on the use of hemostatic agents for tubeless PCNL.

Safety and efficacy of a surgeon-prepared gelatin hemostatic agent compared with FloSeal for hemostasis in laparoscopic partial nephrectomy

BACKGROUND AND PURPOSE

Postoperative hemorrhage is a significant risk after laparoscopic partial nephrectomy (LPN). Hemostatic agents have become increasingly popular as adjuncts to renorrhaphy because of their potential to minimize intracorporeal suturing and lessen warm ischemia time. The objective of our study was to compare the safety and efficacy of an inexpensive, surgeon-prepared hemostatic agent with that of a more expensive, commercially prepared one.

MATERIALS AND METHODS

Between August 2006 and July 2008, 40 LPNs were performed by a single surgeon at two separate institutions. A commercially available gelatin matrix thrombin, FloSeal, was used at one institution (cohort 1, n=19), while a less expensive, surgeon-prepared gelatin hemostatic agent, Gelfoam, was used at a separate institution (cohort 2, n=21) over the same period. Outcomes, including estimated blood loss (EBL), operative time, transfusion rates, and complications, were compared between the two groups.

RESULTS

The median operative and warm ischemia times in cohorts 1 and 2 were 150 (range 132-192) and 16 (range 12-29) minutes and 150 (range 120-300) and 20 (range 14-37) minutes, respectively (P = 0.16, 0.07). The median EBL was 150 mL (range 50-250) and 100 mL (range 50-1000) (P = 0.09), and the postoperative transfusion rate was 0% and 4.8% (P = 0.33). Median LOS was 2 (range 2-7) and 3 (range 2-7) days (P = 0.62). Potential cost saved per case was $200 to $450.

CONCLUSION

As health care costs continue to rise, delivering high-quality care in a cost-effective manner is paramount. Our study demonstrates similar safety and efficacy of a surgeon-prepared, cheaper gelatin matrix compared with FloSeal. Generic hemostatic agents are a viable alternative to more expensive agents in institutions in which commercially available agents are not available or cost prohibitive.

Surgical intervention in the management of postpartum hemorrhage

Obstetric hemorrhage is often a sudden, life-threatening event. Successful management hinges on both preoperative preparation if hemorrhage is anticipated as well as knowledge of interventions. Uterine-sparing techniques, such as aggressive and early use of uterotonics, balloon tamponade, uterine compression sutures, arterial ligation, and selective arterial embolization, may be used to control hemorrhage. If these techniques are not adequate, the decision must be made to proceed with hysterectomy. The type of hysterectomy (subtotal vs. total) must be individualized to each patient. Hemostatic agents may be particularly useful in patients who have excessive blood loss from raw tissue surfaces.

[Adjuvants in operative laryngology: corticosteroids, fibrin adhesives, Mitomycin C]

Medicinal adjuvants are often used in operative laryngology but their value is judged very differently. The scientific evidence is unsatisfactory for most of these substances. For corticosteroids it is proven that in pediatric intensive care they reduce stridor following extubation. Routine prophylactic use for intubation does not seem to be justified and methylprednisolone and dexamethasone are the preferred preparations. Fibrin adhesives are well tolerated and low in side-effects. The indications for their use should be primarily limited due to the cost factor. Their use in laryngology remains a decision on an individual case-to-case basis. Mitomycin C is used because of its antiproliferative effect on fibroblasts in order to reduce scar tissue formation. Many positive effects have been attributed to the topical application but there are large differences in dosage and exposure time.

Renal injury and the application of polysaccharide hemospheres: a laparoscopic experimental model

BACKGROUND AND PURPOSE

Microporous polysaccharide hemospheres (MPH) are hemostatic beads engineered from purified plant starch. MPH accelerates the natural clotting cascade by concentrating clotting factors and proteins on their surface while absorbing aqueous and low molecular weight components from blood. The purpose of this study was to determine the efficacy of MPH in achieving hemostasis in the setting of laparoscopic renal injury.

MATERIALS AND METHODS

In four domestic pigs, 16 laparoscopic renal trocar injuries were created (8 each of 12 and 5 mm). A standard hand-assisted laparoscopic approach was used to each kidney so that two lesions per kidney were randomly created. MPH was applied to each treatment lesion with light pressure maintained for 60 seconds. Four of the 16 lesions, two each of 12 and 5 mm, were allowed to bleed as controls. Hemostasis was defined as no active bleeding or oozing. The animals were sacrificed at the conclusion of the procedure.

RESULTS

The mean time to hemostasis for the 12-mm MPH and control lesions was 196.2 +/- 53.3 and 372.0 +/- 225.6 seconds, while the average blood loss was 8.3 +/- 3.7 and 12.0 +/- 4.9 g, respectively. For the 5-mm MPH and control lesions, the average time to hemostasis was 100.2 +/- 24.8 and 247.0 +/- 134.4 seconds, while the average blood loss was 8.3 +/- 3.8 and 9.0 +/- 0.7 g, respectively. The median number of applications of the MPH for the 5- and 12-mm injuries was 1 and 2, respectively.

CONCLUSIONS

MPH provided a rapid and effective means of hemostasis for laparoscopic renal parenchymal injuries in this model. Additional evaluation is warranted, however, before general application is advisable.

Topical hemostatic agents: a review

Topical hemostatic agents play an important role in both common and specialized dermatologic procedures. These agents can be classified based on their mechanism of action and include physical or mechanical agents, caustic agents, biologic physical agents, and physiologic agents. Some agents induce protein coagulation and precipitation resulting in occlusion of small cutaneous vessels, while others take advantage of latter stages in the coagulation cascade, activating biologic responses to bleeding. Traditional and newer topical hemostatic agents are discussed in this review, and the benefits and costs of each agent will be provided.