Advantages of fibrin glue spray in laparoscopic liver biopsies

A magnesium calcium phosphate-based cement as a bone adhesive: characterization and biomechanical evaluation

BACKGROUND

Usually, comminuted fractures contain fragments that are too small for fixation with Kirschner (K)-wires or screws. For those bony or osteochondral fragments, a bone adhesive would be desirable to, for example, enable easy anatomic reduction, avoid discarding of the fragments, and enable temporary fixation to visualize reduction before definitive osteosynthesis is performed. Most of the currently available bone adhesives have shortcomings, such as cytotoxicity, lack of resorbability, and inadequate mechanical properties. Thus, there is room for improved bone adhesives. The present work involves synthesis, characterization, and biomechanical evaluation of three variants of a novel magnesium calcium phostphate-based cement that may be used as a bone adhesive.

METHODS

Three novel experimental formulations of a magnesium calcium phosphate-based cement and a commercially-available cyanoacrylate bone adhesive (Glubran® 2) were used. The formulations were a magnesium phosphate (Mg3PO4 + MgO + phytic acid) (MPC_25), a magnesium calcium phosphate (Mg2.75Ca0.25PO4 + MgO + phytic acid) (MPCa_22.5), and a magnesium phosphate that had undergone modified temperature stages during sintering (Mg3O8P2 * x H2O) (HT-MPC). In vitro quasi-static compression tests were conducted using cuboid specimens. Split fractures of the lateral tibial plateau were created in dissected porcine tibiae. The lateral fracture fragments were glued onto the condyles. Load was applied on the glued fracture fragments via the femoral component of a knee hemiarthroplasty. Cyclic loading tests with increasing load levels, load-to-failure tests, and torque tests were conducted using this biomechanical model.

RESULTS

Among the experimental cement formulations, HT-MPC had the highest compressive strength (26.8 ± 9.5 MPa), MPCa_22.5 had the highest cyclic increasing load-to-failure (162 ± 40 N) and the highest load-to-failure (295 ± 84 N), while the highest calculated shear strength was obtained with both MPC_25 and MPCa_22.5 (0.27 ± 0.12 and 0.26 ± 0.06 MPa, respectively), and the highest torque-to-failure was obtained with both MPCa_22.5 and HT-MPC (2.2 ± 0.8 and 2.1 ± 1.2 Nm, respectively). The calculated shear strength for the experimental cement formulations (0.13-0.38 MPa) is above the minimum that has been suggested to be required for a bone adhesive to be used in clinical practice (0.2 MPa). Relative to the experimental cement formulations, the compressive strength of Glubran® 2 was significantly lower, but for each of the other four biomechanical parameters, values were significantly higher.

CONCLUSIONS

Each of the synthesized novel magnesium calcium phosphate-based cement formulations has adequate compressive strength, shear strength and resistance to fatigue failure. Thus, each merits further study for use in intraoperative fixation of small bone fragments.

Laser-heated needle for biopsy tract ablation: In vivo study of rabbit liver biopsy

PURPOSE

To investigate the efficacy of a newly-developed laser-heated core biopsy needle in the thermal ablation of biopsy tract to reduce hemorrhage after biopsy using in vivo rabbit's liver model.

MATERIALS AND METHODS

Five male New Zealand White rabbits weighed between 1.5 and 4.0 kg were anesthetized and their livers were exposed. 18 liver biopsies were performed under control group (without tract ablation, n = 9) and study group (with tract ablation, n = 9) settings. The needle insertion depth (~3 cm) and rate of retraction (~3 mm/s) were fixed in all the experiments. For tract ablation, three different needle temperatures (100, 120 and 150 °C) were compared. The blood loss at each biopsy site was measured by weighing the gauze pads before and after blood absorption. The rabbits were euthanized immediately and the liver specimens were stained with hematoxylin-eosin (H&E) for further histopathological examination (HPE).

RESULTS

The average blood loss in the study group was reduced significantly (p < 0.05) compared to the control group. The highest percentage of bleeding reduction was observed at the needle temperature of 150 °C (93.8%), followed by 120 °C (85.8%) and 100 °C (84.2%). The HPE results show that the laser-heated core biopsy needle was able to cause lateral coagulative necrosis up to 14 mm diameter along the ablation tract.

CONCLUSION

The laser-heated core biopsy needle reduced hemorrhage up to 93.8% and induced homogenous coagulative necrosis along the ablation tract in the rabbits' livers. This could potentially reduce the risk of tumor seeding in clinical settings.

Laparoscopic splenic biopsy--porcine to human studies--using a fibrin sealant technique

INTRODUCTION

Splenic biopsies are not routinely performed because of the risk of severe hemorrhage. The aim of this study was to explore the feasibility of performing laparoscopic splenic biopsies using a fibrin sealant in pigs and then to translate this technique into the clinical setting.

METHOD

Four German Landrace pigs underwent a laparoscopic splenic biopsy using a fibrin sealant to occlude the needle tract. Time to achieve hemostasis and postoperative hemorrhage were assessed.

RESULT

The average time to achieve haemostasis was 15 s (range, 8 to 25 s) with no hemorrhage from the needle tract observed. Subsequently this was translated into the clinical setting where a patient also underwent a laparoscopic splenic biopsy without any adverse effect.

CONCLUSIONS

Laparoscopic splenic biopsy with the application of a fibrin sealant is a safe and efficient technique.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.