Perspective: Timely diagnosis and repair of intraoperative thoracic/lumbar cerebrospinal fluid (CSF) leaks.

Background: Our review of 12 articles for this perspective showed the frequency of intraoperative thoracic and/or lumbar CSF fistulas/dural tears (DT) ranged from 2.6% - 8% for primary surgical procedures. Delayed postoperative CSF leak/DT were also diagnosed in 0.83% (17/2052 patients) to 14.3% (2/14 patients) of patients undergoing thoracic and/or lumbar procedures. Further, the rate of recurrent postoperative CSF leaks/DT varied from 13.3% (2/15 patients) to 33.3% (4/12 patients). Methods: Intraoperative, postoperative delayed, and recurrent postoperative traumatic postsurgical thorac CSF leaks/DT can be limited by performing initially sufficient operative decompressions and/or decompressions/fusions (i.e., utilizing adequate open exposures vs. inadequate minimally invasive (MI) approaches). The incidence of CSF leaks/DT can be further reduced by spine surgeons' utilization of operating microscopes, and their avoiding routine attempts at total synovial cyst excision and/or complete resection of hypertrophied/ossified yellow ligament in the presence of significant dural adhesions. Results: Multiple CSF leak/CT repair techniques included; using interrupted, non-resorbable sutures for direct dural repairs (i.e. 7-0 Gore-Tex sutures where the suture is larger than the needle thus plugging needle holes), and adding where needed muscle patch grafts, microfibrillar collagen, the rotation of Multifidus muscle pedicle flaps, fibrin sealants (FS)/fibrin glues (FG), lumbar drains (LD), and/or lumbo-peritoneal (LP) shunts. Conclusion: Intraoperative, postopertive delayed, and/or recurrent postoperative thorac and/or lumbar traumatic surgical CSF leaks can be reduced by choosing to initially perform the appropriately extensive open operative decompressions and/or decompresssions/fusions. It is critical to use an operating microscope, non-resorbable interrupted sutures, and where necessary, muscle patch grafts, microfibrillar collagen, the rotation of Multifidus Muscle Pedicle Flaps, FS/FG, LD, and/or LP shunts.

Efficacy of Flowable Collagen Hemostat Evaluated in Preclinical Models of Liver Injury and Spinal Cord Exposure.

Introduction: Excessive bleeding in trauma and surgical settings leads to increased operative time, reoperation rates, and overall healthcare costs. A wide range of hemostatic agents have been developed to control bleeding that can vary considerably in type of hemostatic action, ease of application, cost, risk of infection, and dependence on patient coagulation. Microfibrillar collagen-based hemostatic materials (MCH) have yielded beneficial results in a variety of applications. Methods: A new flowable collagen product, containing a modified MCH flour, but in a more convenient flowable delivery system, was evaluated for hemostatic efficacy in preclinical models of solid organ injury and spinal cord exposure. The primary objective of this study was to compare the hemostatic potential and local tissue responses to this novel, flowable collagen-based hemostatic agent to the original flour formulation to confirm that the new method of delivery did not interfere with the hemostatic properties of the MCH flour. Results: When observed visually, the flowable MCH flour mixed with saline (FL) provided more precise application and uniform coverage to injured tissues compared to the dry MCH flour alone (F0). All of the treatments (FL, F0, and gauze) exhibited comparable Lewis bleed grade at all three time points evaluated in the capsular resection liver injury model (bleed grade: 1.0-1.3; p> 0.05 in all cases). FL and F0 exhibited comparable 100% acute hemostatic efficacy and similar long-term histomorphological properties (up to 120 days) in a capsular resection liver injury in pigs, while gauze resulted in significantly lower rates of acute hemostatic efficacy (8-42%, p<0.05 in all cases). In an ovine model of dorsal laminectomy and durotomy, FL and F0 again exhibited comparable results without any neurological effects. Conclusion: Flowable microfibrillar collagen was shown to yield favorable short- and long-term outcomes in two representative applications where hemostatic efficacy is critical to surgical success.

The role of hemostatic devices in neurosurgery. A systematic review.

Hemostasis represents a fundamental step in every surgical procedure. During neurosurgical procedures, proper and robust hemostasis into confined spaces can significantly reduce the odds of perioperative complications. Over the decades, multiple methods have been applied, and several medical devices have been developed to promote and guarantee proper hemostasis. This study presents a systematic review of the most used intraoperative hemostatic methods and devices in neurosurgery. Insightful research was performed on the PubMed database according to the PRISMA guidelines. This comprehensive review of scientific literature represents a synoptic panel where the most used intraoperative hemostatic methods and devices available today in neurosurgery are classified and described.

Avitene™ Microfibrillar Collagen Hemostat for Adjunctive Hemostasis in Surgical Procedures: A Systematic Literature Review.

Adequate hemostasis during surgical procedures is essential for successful patient outcomes and reduced healthcare resource utilization. Topical hemostatic agents can act as catalysts for the clotting cascade or as a scaffold to promote platelet activation or aggregation. Although an ever-increasing number of topical absorbable hemostatic agents are now available for perioperative use, health care providers are disadvantaged by the lack of comparative data on feasibility, clinical effectiveness, advantages, and limitations of each in specific surgical settings. This knowledge is important for appropriate product choice when patient characteristics, type of surgical procedure, type of bleeding, and product availability may differ widely. This manuscript provides the first comprehensive overview of Avitene™ Microfibrillar Collagen Hemostat (MCH), a bovine collagen-based absorbable hemostat that has been widely used for over four decades in the United States and abroad. MCH is indicated as an adjunct to hemostasis across a broad spectrum of surgical specialties and has been shown to achieve hemostasis with positive patient outcomes and a favorable safety profile in many applications, including hepatic, orthopedic, splenic, oral, and otolaryngologic surgery. Although published clinical data regarding the use of MCH in cardiovascular surgery is limited, evidence suggests moderate use in this specialty. The information contained in this systematic review will help health care providers understand the clinical use and effectiveness of the product to determine appropriate use in differing bleeding scenarios across multiple surgical specialties. Future studies may include comparative functional and cost analyses to explore the economic advantages of using absorbable hemostatic agents compared with each other or with conventional techniques of hemostasis, when appropriate.

Randomized Clinical Trial Comparing Three Local Hemostatic Agents for Dental Extractions in Patients under Chronic Anticoagulant Therapy - A Comparative Study.

INTRODUCTION: Oral anticoagulants are widely used worldwide for many systemic diseases. Recent oral surgical protocols suggest that therapeutic levels of the anticoagulant drug should be maintained for simple dental extractions because bleeding complications could be managed with proper local hemostasis. The aim of the present study was to compare bleeding complication of three different local hemostatic agents for dental extractions without interrupting drug administration in patients undergoing oral Vitamin K antagonist chronic anticoagulant therapy. MATERIAL AND METHODS: Randomized control trial of three hemostatic agents for dental extractions, in patients under oral anticoagulant therapy without drug interruption. The present study included 240 patients with international normalized ratio between 1.5 and 3.5. Patients took their anticoagulation drug normally. A single surgeon performed calibrated simple dental extractions and applied a plug of bismuth subgallate (BS), fibrin tissue adhesive (FTA) or microfibrillar collagen (MC), assigned randomly. Statistical analysis of bleeding between the groups was performed using the Chi-square test. RESULTS: There was no hemorrhagic complication in the BS group, and only one in the FTA group. However, in the MC group, 10 patients (12.5%) suffered postoperative bleeding. Data analysis showed statistical differences between the MC group and the other two groups (P < 0.05). DISCUSSION: BS and FTA showed similar clinical effectiveness and were more effective than MC for the control of postoperative bleeding in oral anticoagulated patients.

Postoperative cytological findings from the use of the Integran microfibrillar collagen hemostatic matrix in conization.

The Integran microfibrillar collagen hemostatic matrix is one form of microfibrillar collagen hemostat. This form has a sheet-type structure and has explicitly been used in Japan. In gynecology, this sheet-type matrix has helped effect uterine surface hemostasis, especially in myomectomy and cervical conization. However, cytotechnologists and pathologists have overlooked the foreign materials used for conization in postoperative cervical cytology. We report two cases describing the characteristic cervical cytology findings when Integran was used in conization. The first case was a 67-year-old woman who underwent conization because of cervical intraepithelial neoplasia (CIN) 3. Thirty-six days after the surgery, many cylindrical fragments of glossy acellular materials appeared in the cervical cytology. Fortunately, the content did not impede the diagnosis of NILM. The patient then underwent hysterectomy two months after conization. Surgical specimen revealed a high degree of inflammation and granulation without malignancy. Following surgery, the cylindrical fragments disappeared from microscopic findings. The second case was a 45-year-old woman who underwent conization because of CIN3. Thirty-four days after the surgery, many tubular pieces of glossy acellular materials appeared in cervical cytology, as seen in the first case. The cytological diagnosis was NILM. One hundred days after surgery, cervical cytology revealed many clue cells but no cylindrical fragments. These clusters of cylindrical fragments of glossy acellular materials in cervical cytology after conization might induce a delay in diagnosing the persistence and recurrence of cervical cancer. This article is the first report describing cervical cytology findings associated with Integran use.

Trans-splenic Access for Portal Venous Interventions in Children: Do Benefits Outweigh Risks?

BACKGROUND: The primary concern of trans-splenic access for portal interventions is the risk of life-threatening intraperitoneal bleeding. OBJECTIVE: To review the clinical indications and efficacy and evaluate the risk factors for intraperitoneal bleeding during trans-splenic portal interventions in children. MATERIALS AND METHODS: A retrospective review of consecutive patients who underwent trans-splenic portal interventions at a tertiary care pediatric institution between March 2011 and April 2017 was performed. Forty-four procedures were performed in 30 children with a median age of 5 (0.3-18) years. Clinical indications, technical success, procedural success, and incidence of complications were recorded. Potential risk factors for intraperitoneal bleeding were evaluated using Wilcoxon rank and Fisher's exact tests. RESULTS: Trans-splenic access was 100% successful. In 35/44 (79%) procedures, the subsequent intervention was successful including recanalization of post-transplant portal vein occlusion in 10/13, embolization of bleeding Roux limb varices in 8/8, recanalization of chronic portal vein thrombosis in native liver in 7/13, splenoportography and manometry in 6/6, and occlusion of portosystemic shunts in 4/4 procedures. Intraperitoneal bleeding occurred during 12/44 (27%) procedures and was managed with analgesics, blood transfusion, and peritoneal drainage without the need for splenectomy or splenic artery embolization. Statistically significant correlation of bleeding was found with intraprocedural anticoagulation, but not with patient age, weight, platelet count, INR, ascites, splenic length, splenic venous pressure, vascular sheath size, or tract embolization technique. CONCLUSION: Trans-splenic access is a useful technique for successful pediatric portal interventions. Although it entails a substantial risk of intraperitoneal bleeding, this can be managed conservatively.

Liver Track Embolization After Islet Cell Transplant: Comparison of Two Techniques.

OBJECTIVE: The purpose of this study was to compare the efficacy and safety of microfibrillar collagen paste with those of gelatin sponge for liver track embolization after islet cell transplants. MATERIALS AND METHODS: In a single-institution, retrospective study, 37 patients underwent 66 islet cell transplants from January 2005 through October 2015. Transplants were performed with 6-French transhepatic access, systemic anticoagulation, pretransplant and posttransplant portal venous pressure measurement, and image-guided liver track embolization with gelatin sponge (2005-2011) or microfibrillar collagen paste (2012-2015). The findings on 20 patients (two men, 18 women; mean age, 48 years) who underwent 35 gelatin sponge embolizations were compared with the findings on 13 patients (six men, seven women; mean age, 48 years) who underwent 22 microfibrillar collagen paste embolizations (four patients, nine procedures without embolization excluded). Medical record review was used to compare laboratory test results, portal venous pressures, and 30-day adverse bleeding events (classified according to Society of Interventional Radiology and Bleeding Academic Research Consortium criteria) between groups. RESULTS: The technical success rates were 100% in the microfibrillar collagen paste group and 91% in the gelatin sponge group. Group characteristics were similar, there being no differences in platelet count, partial thromboplastin time, or number of islet cell transplants per patient (p > 0.05). A statistical difference in international normalized ratio (1.0 versus 1.1) was not clinically significant (p = 0.012). Posttransplant portal venous pressure was slightly higher among patients treated with gelatin sponge (13 versus 9 mm Hg, p = 0.002). No bleeding occurred after microfibrillar collagen paste embolization, whereas nine bleeding events followed gelatin sponge embolization (0% versus 26%, p = 0.020). In univariate comparison of bleeding and nonbleeding groups, the use of gelatin sponge was statistically associated with postprocedure hemorrhage. CONCLUSION: Microfibrillar collagen paste is effective and safe for liver track embolization to prevent bleeding after islet cell transplants. It appears to be more efficacious than gelatin sponge.

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.