Sutureless nephron-sparing surgery: Use of albumin glutaraldehyde tissue adhesive (BioGlue)

Protein-based tissue adhesive reduces time to haemostasis in peripheral vascular surgery

OBJECTIVES

The aim of this study was to evaluate the effectiveness of protein-based tissue adhesive (Bioglue®) in reducing time to haemostasis in patients undergoing peripheral vascular surgery.

METHODS

From January to December 2021, 100 consecutive patients from 4 centres have been treated with open peripheral vascular surgery including upper and lower limb interventions. Patients have been allocated in each centre into control with no use of Bioglue® (Group no-Bio, 50 patients) or use of Bioglue® (Group Bio, 50 patients) by a block randomization method 10:10 until the required sample size was reached. Perioperative parameters including time to haemostasis, number of adjunctive stitches, and in-hospital bleeding have been analysed and compared in the two groups by means of mean independent-samples tT -test and Gehan-Breslow-Wilcoxon test.

RESULTS

Both groups were homogeneous in terms of demographic data, preoperative risk factors, and preoperative medical therapy except for a higher percentage of active smokers in Group Bio (52% vs. 24%, p = 0.004). Femoral endarterectomy was most common in Group Bio (44% vs. 24%, p = 0.03), whilst the percentage of lower limb vein bypasses was higher in Group no-Bio (50% vs. 36%, p = 0.03). Bovine pericardium was the preferred material in Group Bio (20 cases, 40%), whilst autologous vein is mostly used in Group no-Bio (26 cases, 52%) (p = 0.01). Time to haemostasis was faster in Group Bio (4.4 vs. 9.6 minutes, p < 0.001). The need for adjunctive stitches was higher in Group no-Bio (8 cases, 16%, Group Bio vs. 25 cases, 50%, Group no-Bio; p < 0.001). The overall rate of in-hospital bleeding, including those requiring reintervention, was not different between the two groups (9 cases, 18%, Group Bio vs. 7 cases, 14%, Group no-Bio; p = 0.39).

CONCLUSIONS

The protein-based tissue adhesive Bioglue® reduced time to haemostasis and need for adjunctive stitches in peripheral vascular surgery. However, it did not affect the overall rate of perioperative bleedings. Further studies with larger sample sizes are needed to validate these outcomes.

Reconstruction Techniques After Partial Nephrectomy: Classic vs. Sutureless Approach-A Narrative Review

PURPOSE OF REVIEW

The purpose of this review is to update the information about the different types of reconstruction after partial nephrectomy, with special emphasis on the new methods of suture-free hemostasis currently available.

RECENT FINDINGS

The aim of renal reconstruction is to avoid bleeding and leakage of the collecting system, but now the renorrhaphy technique used is considered one of the modifiable determinants of renal function after surgery. In an attempt to avoid the loss of renal function implicit in classic reconstruction, new techniques have been described to control hemostasis and urinary leakage, which employ fewer suture layers, different suture materials and designs, and a wide range of commercially available hemostatic materials. Multiple suture characteristics have been studied as a potential factor influencing the renal function observed after partial nephrectomy. Single-plane suture techniques, the use of bearded sutures, and running sutures seem to be associated with less deterioration in postoperative renal function, and deep medullary sutures should be avoided to avoid affecting the arcuate arteries. Sutureless hemostasis systems could prevent the deterioration of renal function and complications derived from suturing, also reducing ischemia time and surgical time without increasing the risk of complications.

Naturally derived highly resilient and adhesive hydrogels with application as surgical adhesive

The inadequacy of conventional surgical techniques for wound closure and repair in soft and resilient tissues may lead to poor healing outcomes such as local tissue fibrosis and contracture. Therefore, the development of adhesive and resilient hydrogels that can adhere firmly to irregular and dynamic wound interfaces and provide a "tension-free proximity" environment for tissue regeneration has become extremely important. Herein, we describe an integrated modeling-experiment-application strategy for engineering a promising hydrogel-based bioadhesive based on recombinant human collagen (RHC) and catechol-modified hyaluronic acid (HA-Cat). Molecular modeling and simulations were used to verify and explore the hypothesis that RHC and HA-Cat can form an assembly complex through physical interactions. The complex was synergistically crosslinked via a catechol/o-quinone coupling reaction and a carbodiimide coupling reactions, resulting in superior hydrogels with strong adhesion and resilience properties. The application of this bioadhesive to tissue adhesion and wound sealing in vivo was successfully demonstrated, with an optimum collagen index, epidermal thickness, and lowest scar width. Furthermore, subcutaneous implantation demonstrated that the bioadhesive exhibited good biocompatibility and degradability. This newly developed hydrogel may be a highly promising surgical adhesive for medical applications, including wound closure and repair.

A new surgical technique for sutureless partial nephrectomy: renal sutureless device

BACKGROUND

Several factors impact the preservation of renal function after partial nephrectomy. Warm ischemia time is the main modifiable surgical factor. Renorrhaphy represents the key of hemostasia, but it is associated with increase of warm ischemia time and complications. The aim of this study was to describe our initial surgical experience with a new surgical technique for sutureless partial nephrectomy, based on the application of our own developed renal-sutureless-device-RSD.

METHODS

Between 2020-2021, 10 patients diagnosed with renal cell carcinoma stage cT1a-b cN0M0 with an exophytic component were operated using renal-sutureless-device-RSD. Surgical technique of sutureless partial nephrectomy with renal-sutureless-device-RSD is described in a step-by-step fashion. Clinical data was collected in a dedicated database. Presurgical, intraoperative, postoperative variables, pathology and functional results were evaluated. Medians and ranges of values for selected variables were reported as descriptive statistics.

RESULTS

Partial nephrectomy was carried out with the use of renal-sutureless-device-RSD without renorrhaphy in all cases (70%cT1a-30%cT1b). Median tumor size was 3.15 cm (IQR: 2.5-4.5). R.E.N.A.L Score had a range between 4a-10. Median surgical time was 97.5 minutes (IQR 75-105). Renal artery clamping was only required in 4 cases, with a median warm ischemia time of 12.5 minutes (IQR 10-15). No blood transfusion, intraoperative and postoperative complications were noted. Free-of-disease margin rate achieved was 90%. Median length of stay was 2 days (IQR 2-2). Laboratory data on hemoglobin and hematocrit levels, as well as renal function tests, remained stable after partial nephrectomy.

CONCLUSIONS

Our initial experience suggests that a sutureless PN using the RSD device is feasible and safe. Further investigation is needed to determine the clinical benefit of this technique.

Systematic review on active treatment for urinary fistula after partial nephrectomy

INTRODUCTION

Urinary fistula is expected to become more frequent in urological practice as a result of expanding indication of partial nephrectomy given it's oncological results equivalent to those of radical nephrectomy but at a lower risk of progression to chronic kidney disease, lower cardiovascular morbidity, and overall mortality.

OBJECTIVES

Review and compare different techniques of contemporary active management for urinary fistula after partial nephrectomy.

METHODS

A systematic literature search on the MEDLINE database was conducted in March 2020, combining the terms: "urine leak", "urine leakage", "urinary leak" and "urinary fistula", with: "partial nephrectomy", "nephron sparing surgery" and "renal sparing surgery". This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Only articles related to active treatment were eligible. Abstracts in English and Spanish from the last two decades were screened. No restriction based on study design nor the length of follow-up.

PRIMARY OUTCOMES

1) Leak resolution rate 2) Time course of leak resolution and 3) Number of interventions needed for resolution.

RESULTS

Multiple studies were found. There were no randomized controlled trials. Urinary fistula can be solved in many ways with active treatment, with a high success rate (97.5%), an average of 1.4 intervention-per-patients and a mean time for leak resolution of 11 days (median of 3 days).

CONCLUSION

There is a high risk of bias due to the study's methodology. There is a broad range of effective alternatives and various approaches to solve urinary fistula in an appropriate timing.

Safety and performance of surgical adhesives

BACKGROUND

Tissue adhesives are an alternative to conventional surgical sutures to reduce the time and cost of wound closure and to improve patient comfort. The use of tissue adhesives does not require any subsequent intervention and significantly lowers the volume and rate of blood loss, and reduces the need for transfusions during and after surgery. However, based on their formulation, tissue adhesives' safety profile and functional properties may differ. Therefore, this study aimed to evaluate the basic safety and performance of NE'X Glue® Surgical Sealant, BioGlue® Surgical Sealant, and PREVELEAKTM Surgical Sealant in vitro.

METHODS

The basic safety of commercially available tissue adhesives was evaluated using MEM elution assay according to ISO 10993-5 and endotoxin level according to 85. USP. The in vitro performance was evaluated using lap-shear by tension loading test, burst strength test, degradation, and swelling assays.

RESULTS

NE'X Glue®, BioGlue®, and PREVELEAKTM did not cause cytotoxicity in MEM elution assay. All surgical adhesives are below the general limit of endotoxin contamination of 20 EU/device. NE'X Glue® and BioGlue® showed the highest and comparable strength properties in lap shear and burst strength tests compared to PREVELEAKTM. NE'X Glue® and PREVELEAKTM are characterized by lower degradation potential than BioGlue®. PREVELEAKTM is characterized by the highest swelling when compared to NE'X Glue® and BioGlue®.

CONCLUSIONS

NE'X Glue® is most versatile in terms of functional properties while maintaining the same safety profile as BioGlue® and PREVELEAKTM.

Injectable Adhesive Hydrogels for Soft tissue Reconstruction: A Materials Chemistry Perspective

Injectable bioadhesives offer several advantages over conventional staples and sutures in surgery to seal and close incisions or wounds. Despite the growing research in recent years few injectable bioadhesives are available for clinical use. This review summarizes the key chemical features that enable the development and improvements in the use of polymeric injectable hydrogels as bioadhesives or sealants, their design requirements, the gelation mechanism, synthesis routes, and the role of adhesion mechanisms and strategies in different biomedical applications. It is envisaged that developing a deep understanding of the underlying materials chemistry principles will enable researchers to effectively translate bioadhesive technologies into clinically-relevant products.

Highly stretchable, compressible, adhesive hydrogels with double network

In this work, a double network bovine serum albumin-polyacrylamide (BSA-PAM) adhesive hydrogel was fabricated, in which combination of physical interactions including hydrogen bonds and chain entanglements, and chemical covalent photo-crosslinking. The BSA-PAM hydrogel exhibited excellent mechanical and adhesive properties. The composite hydrogel not only demonstrated excellent tensile properties (maximum force elongation 1552%~2037%), but also displayed extremely high fatigue resistance even when subjected to compress strains of up to 85%. More importantly, the BSA-PAM hydrogel showed excellent adhesiveness to various substrates (90 kPa~150 kPa for glass and 9.74 kPa~35.09 kPa for pigskin). This work provided a facile way of fabricating tough, stretchable and adhesive BSA-PAM hydrogels.

Comparison of Sutureless Versus Suture Partial Nephrectomy for Clinical T1 Renal Cell Carcinoma: A Meta-Analysis of Retrospective Studies

Background

Partial nephrectomy (PN) is the recommended treatment for T1 renal cell carcinoma (RCC). Compared with suture PN, sutureless PN reduces the difficulty and time of operation, but the safety and feasibility have been controversial. This meta-analysis was conducted to compare the function and perioperative outcomes of suture and sutureless PN for T1 RCC.

Methods

Systematic literature review was performed up to April 2021 using multiple databases to identify eligible comparative studies. According to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria, identification and selection of the studies were conducted. Meta-analysis was performed for studies comparing suture to sutureless PN for both T1a and T1b RCC. In addition, subgroup analysis was performed on operation time, warm ischemia time, estimated blood loss, and postoperative complications. Sensitivity analysis was used in analysis with high heterogeneity (operation time and estimated blood loss).

Results

Eight retrospective studies were included with a total of 1,156 patients; of the 1,156 patients, 499 received sutureless PN and 707 received suture PN. The results showed that sutureless PN had shorter operative time (I² = 0%, P < 0.001), warm ischemia time (I² = 97.5%, P < 0.001), and lower clamping rate (I² = 85.8%, P = 0.003), but estimated blood loss (I² = 76.6%, P = 0.064) had no difference. In the comparison of perioperative outcomes, there was no significant difference in postoperative complications (I² = 0%, P = 0.999), positive surgical margins (I² = 0%, P = 0.356), postoperative estimated glomerular filtration rat (eGFR) (I² = 0%, P = 0.656), and tumor recurrence (I² = 0%, P = 0.531).

Conclusions

In T1a RCC with low RENAL score, sutureless PN is a feasible choice, whereas it should not be overestimated in T1b RCC.

Hemostatic Agent May Improve Perioperative Outcomes in Partial Nephrectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Hemostatic agents (HAs) are used to achieve hemostasis and prevent postoperative complications in multiple surgeries, but the role of HAs is ambiguous during partial nephrectomy (PN), so this study aimed to assess the role of HAs in PN.

METHODS

PubMed, Embase, CENTRAL and ClinicalTrials.gov were searched for randomized controlled trials and cohort studies regarding the comparison of HA use alone and standard suturing during PN on January 17, 2020. RevMan 5.3 was used to conduct meta-analysis. Sensitivity analyses and subgroup analyses were performed based on surgical procedures and HA types.

RESULTS

Six studies involving 1,066 patients were included. The quality of studies was moderate to high. There were significant reductions in warm ischemia time (mean difference [MD] = -6.30 min, 95% confidence interval [CI] -7.70 to -4.90, p < 0.00001), operative time (MD = -19.81 min, 95% CI -27.54 to -12.08, p < 0.00001), and estimated blood loss (MD = -108.62 mL, 95% CI -177.27 to -39.9, p = 0.002) in the HA group, and HA use alone did not increase postoperative complications. The results were similar in the subgroup analyses and sensitivity analyses.

CONCLUSION

HA may be an effective and safe surgical material in PN, which can improve postoperative outcomes. High-quality and randomly designed studies are needed to validate the applicability.

The Effects of Using Bioglue in Nasal Septal Surgery

OBJECTIVES

Nasal septal surgery is one of the most common surgical procedure performed by otolaryngologists. Nasal packs are used for bleeding control, prevention of septal hematoma, replacement of mucoperichondrial flaps, and stabilization of the septum after nasal septal surgery. The aim of this study was to investigate the effects of albumin-glutaraldehyde-based tissue adhesive (Bioglue), which can be used as an alternative to nasal pack on the nasal septum after experimental nasal septum surgery.

METHODS

A total of 16 female Wistar albino rats were randomly separated into the study group (n = 10) and the control group (n = 6). After raising the mucoperichondrial flap on one side of the septum, Bioglue was used to fix the mucoperichondrial flap over the septal cartilage ın the study group and nasal packs (Merocel) were used for fixation in the control group. The rats were sacrificed at 2 and 4 weeks after septoplasty. All the tissue samples were evaluated under light microscope by the same pathologist in respect of foreign-body reaction, degree of inflammation, granulation tissue, fibrosis, cartilage damage, and cilia and goblet cell damage. In the control group, the Merocel packs were removed after 2 days and the groups were compared in terms of hematoma.

RESULTS

No hematoma was observed in any group. Septal perforation was determined in all the study group participants and loss of cilia and goblet cells and foreign-body reaction were found in 8 samples of the study group participants and in none of the control group.

CONCLUSIONS

The results of this study show that Bioglue caused segmental cartilage injury; therefore, it may not suitable for use following septal surgery.

Hemostatic strategies for uncontrolled bleeding: A comprehensive update

Uncontrolled bleeding remains the leading cause of morbidity and mortality across the entire macrocosm. It refers to excessive loss of blood that occurs inside of body, due to unsuccessful platelet plug formation at the injury site. It is not only limited to the battlefield, but remains the second leading cause of death amongst the civilians, as a result of traumatic injury. Startlingly, there are no effective treatments currently available, to cater the issue of internal bleeding, even though early intervention is of utmost significance in minimizing the mortality rates associated with it. The fatal issue of uncontrolled bleeding is ineffectively being dealt with the use of pressure dressings, tourniquet, and surgical procedures. This is not a practical approach in combat arenas or in emergency situations, where the traumatic injury inflicted is deep inside the body, and cannot be addressed externally, by the application of topical dressings. This review focuses on the traditional hemostatic agents that are used to augment the process of hemostasis, such as mineral zeolites, chitosan based products, biologically active agents, anti-fibrinolytics, absorbable agents, and albumin and glutaraldehyde, as well as the micro- and nano-based hemostatic agents such as synthocytes, thromboerythrocytes, thrombosomes, and the synthetic platelets.

Hemostatic agent use during partial nephrectomy: trends, outcomes, and associated costs

PURPOSE

To evaluate the ability of hemostatic agents (HA) to limit bleeding complications following partial nephrectomy (PN) and determine HA usage and costs as well as factors associated with post-operative bleeding complications.

METHODS

The records of 429 PN performed for kidney cancers were reviewed for clinical, pathologic, and perioperative variables. Surgical approach, HA use, and HA expenditure were determined. Bleeding complications and management to 90 days after PN were annotated. Wilcoxon rank-sum and two-sample t tests identified factors associated with HA use. Univariate and limited multivariate logistic regression determined variables associated with bleeding complications.

RESULTS

Use of HA was associated with longer OR duration, longer ischemia time, higher EBL, and method of PN (OPN and LPN > RPN) (all p values < 0.001). On bivariate analysis, while multiple factors were associated with bleeding complications, neither HA use (p = 0.924) nor the number of HA used (two agents vs one p = 0.712; three agents vs. one p = 0.606) were. A multivariable model noted that increasing RENAL score (p = 0.013) and surgical approach (OPN vs. RPN [p = 0.009] and LPN vs. RPN (p = 0.002]) were independently associated with bleeding complications, while HA use was not (p = 0.294). During the 16 years of analysis, a total of $77,687 USD was spent on HA. Average annual HA expenditure was $4855 USD with the peak being in 2010 where expense was $14,086. Mean annual costs for HA use were greater for OPN vs RAPN starting in 2013 (p = 0.02) CONCLUSIONS: The use of HA during PN was not associated with lower rates of bleeding complications. Therefore, judicious use in a case-specific manner is requisite to limit potentially unnecessary operative cost.

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.

Formulation and Functional Properties of Whey Protein-Based Tissue Adhesive Using Totarol as an Antimicrobial Agent

Tissue adhesives have been widely used in surgical procedures. Compared to traditional surgical sutures, tissue adhesives provide fast bonding experiences and full closure of wounds. However, current tissue adhesives are mostly fossil-based synthetic products. Therefore, it is of great significance to explore the use of natural materials in tissue adhesives. Whey is a low-end byproduct of cheese manufacturing. Whey protein, a group of small globular proteins, can exhibit adhesive properties if their structures are modified by physical or chemical means. The objectives of this study were to investigate the functional and structural properties of whey protein-based tissue adhesive, along with the antibacterial effect of totarol, a natural antimicrobial agent. Whey protein isolate (WPI) solutions (25%–33% protein) were mixed with different levels (0.1%–0.3% w/w) of totarol. The mixtures were analyzed for total plate count and yeast and mold count. The lap-shear bonding strength was tested after the WPI-totarol solutions were mixed with a crosslinking agent, glutaraldehyde (GTA). The lap-shear bonding strength of the tissue adhesive was about 20 kPa, which is comparable to that of a commercial BioGlue®. The microstructures of the mixtures were analyzed by scanning electron microscopy (SEM).

Surgical applications of intracorporal tissue adhesive agents: current evidence and future development

Introduction: Traditional mechanical closure techniques pose many challenges including the risk of infection, tissue reaction, and injury to both patients and clinicians. There is an urgent need to develop tissue adhesive agents to reform closure technique. This review examined a variety of tissue adhesive agents available in the market in an attempt to gain a better understanding of intracorporal tissue adhesive agents as medical devices.Areas covered: Fundamental principles and clinical determinants of the tissue adhesives were summarized. The available tissue adhesives for intracorporal use and their relevant clinical evidence were then presented. Lastly, the perspective of future development for intracorporal tissue adhesive were discussed. Clinical evidence shows current agents are efficacious as adjunctive measures to mechanical closure and these agents have been trialed outside of clinical indications with varied results.Expert opinion: Despite some advancements in the development of tissue adhesives, there is still a demand to develop novel technologies in order to address unmet clinical needs, including low tensile strength in wet conditions, non-controllable polimerization and sub-optimal biocompatibility. Research trends focus on producing novel adhesive agents to remit these challenges. Examples include the development of biomimetic adhesives, externally activated adhesives, and multiple crosslinking strategies. Economic feasibility and biosafety are limiting factors for clinical implementation.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Use of Whey Protein as a Natural Polymer for Tissue Adhesive: Preliminary Formulation and Evaluation In Vitro

The use of sutures is still the most widely practiced solution for wound closure and tissue reconstruction; however, scarring is a common defect resulting from sutures on topical use. In some cases, the conventional sutures are unable to seal the sites where fluid and air leakage could occur. Tissue adhesives though have lower tensile strength than sutures, may make scarless surgery possible, or prevent fluid and air leakage. A product called BioGlue^® (CryoLife Inc, Kennesaw, GA, USA), based on bovine serum albumin (BSA, a protein) and glutaraldehyde (GTA, crosslinker), has been approved for clinical use in the USA. Whey protein, a byproduct of cheese-making, comprised mainly of β-lactoglobulin, α-lactalbumin and BSA. Even though the molecular weight of BSA is about three times larger than the molecular of β-lactoglobulin and α-lactalbumin, all three proteins are rich in free ε-amino groups (can react with GTA) and globular proteins. This similarity make whey protein a potential candidate to replace BSA in the tissue adhesive since whey protein is abundant and much cheaper than BSA. In this study, whey protein isolate (WPI) was used as a protein polymer with GTA as a crosslinker to evaluate the feasibility of whey protein for tissue adhesive formulation. Results showed that the WPI/GTA adhesive exhibited a comparable adhesive strength to BioGlue^® control.

The impact of comorbidities, sex and age on the occurrence of acute kidney injury among patients undergoing nephron-sparing surgery

Background

The aim of this study was to report the impact of patients' baseline characteristics on the incidence of acute kidney injury (AKI) after nephron-sparing surgery (NSS) for localized kidney cancer.

Patients and methods

Data from our kidney cancer database were retrospectively extracted to include 402 patients who underwent NSS between March 2000 and June 2016, and had sufficient data. Definition of AKI was based on the postoperative serum creatinine levels and estimated glomerular filtration rate (eGFR) magnitude, which were measured during the 72 h after surgery.

Results

Based on RIFLE and AKIN criteria, the overall rate of postoperative AKI was 35%. The average decrease in eGFR among patients who developed AKI was 20% as compared with the non-AKI subgroup (2%). In univariate analysis, variables that were associated with AKI included right-sided tumors (p = 0.014), male sex (p = 0.01), hypertension (p = 0.003), baseline eGFR (p = 0.009) and history of nephrolithiasis (p = 0.039). However, multivariate analysis revealed that the only independent predictors of postoperative AKI were hypertension (p = 0.009) and cigarette smoking (p = 0.024).

Conclusion

AKI is a common complication of NSS affecting about one-third of the patients. The most important risk factors are hypertension and smoking.

The use of bovine serum albumin-glutaraldehyde tissue adhesive (BioGlue®) for tumor bed closure following open partial nephrectomy

OBJECTIVES

To report the results of the use of Bovine Serum Albumin-Glutaraldehyde tissue adhesive (BioGlue®) for tumor bed closure in open nephron-sparing surgery (NSS).

MATERIALS AND METHODS

The cohort included 255 patients with enhancing renal mass who underwent open NSS. We used open flank approach, with in-situ hypothermia and enucleation of the tumor. For tumor bed closure, we used the BioGlue^® sealant for tumor bed filling, without suturing the edges.

RESULTS

Mean patients' age was 65.4 years. 5.1% of patients had pre-operative chronic renal failure. Mean renal mass diameter was 4.2±1.6cm and mean R.E.N.A.L nephrometry score was 8.0±1.6. Mean ischemia time was 21.8±7.6. Mean estimated blood loss was 42±82ml and only two patients required blood transfusion. Urine leak and pseudo-aneurysm were recorded in two and one patient, respectively. None of the operations were converted to radical nephrectomy. The average change between post-operative and pre-operative eGFR (Δ=-1.7ml/min) was insignificant in a mean follow-up of 30.1±29.6 months. The 10-year recurrence-free survival rate was 99% and the 10-year overall survival rate was 85%.

CONCLUSIONS

The use of BioGlue^® alone for hemostasis after NSS is a feasible and safe alternative to classical suturing. Its use enables satisfactory functional outcome and could potentially reduce ischemia time.

Application of Materials as Medical Devices with Localized Drug Delivery Capabilities for Enhanced Wound Repair

The plentiful assortment of natural and synthetic materials can be leveraged to accommodate diverse wound types, as well as different stages of the healing process. An ideal material is envisioned to promote tissue repair with minimal inconvenience for patients. Traditional materials employed in the clinical setting often invoke secondary complications, such as infection, pain, foreign body reaction, and chronic inflammation. This review surveys the repertoire of surgical sutures, wound dressings, surgical glues, orthopedic fixation devices and bone fillers with drug eluting capabilities. It highlights the various techniques developed to effectively incorporate drugs into the selected material or blend of materials for both soft and hard tissue repair. The mechanical and chemical attributes of the resultant materials are also discussed, along with their biological outcomes in vitro and/or in vivo. Perspectives and challenges regarding future research endeavors are also delineated for next-generation wound repair materials.

Bovine serum albumin-glutaraldehyde (BioGlue®) tissue adhesive versus standard renorrhaphy following renal mass enucleation: a retrospective comparison

BACKGROUND

To present the operative and post-operative comparison between patients who underwent tumor-bed closure with sutures compared with bovine serum albumin-glutaraldehyde (BioGlue^®) tissue sealant only.

METHODS

We retrospectively analyzed data from our ongoing database of 507 eligible patients who underwent open NSS nephron-sparing surgery in our department between January 1995 and May 2014. Patients had tumor-bed closure with sealant adhesive (255 patients) or standard suture technique (252 patients). Demographic, clinical and perioperative data were compared between the two groups, by Chi-square test or by Fisher-Irwin exact test for categorical variables, and by t test for differences in means or by Wilcoxon rank sum test for continuous variables. A multivariate analysis was also done.

RESULTS

Patients' baseline characteristics showed similar distribution of the analyzed parameters among both groups, with few differences: younger age in the sealant group (65.4 versus 68.4 years, p = 0.01) and slightly larger mass size in the suture group (4.0 versus 3.9 cm, p = 0.03). Ischemia time was significantly shorter in the sealant group (21.8 versus 27.0 minutes, p = 0001). Blood loss and transfusion rate (0.8% versus 11.9%, p = 0.0001) were significantly less in the sealant group. A multivariate analysis showed date of surgery and blood loss as the major parameters affecting transfusion rate.

CONCLUSIONS

Closing the tumor bed with BioGlue^® tissue adhesive is feasible, safe, can shorten ischemia time and potentially reduce transfusion rate.

Milk Protein Polymer and Its Application in Environmentally Safe Adhesives

Milk proteins (caseins and whey proteins) are important protein sources for human nutrition; in addition, they possess important natural polymers. These protein molecules can be modified by physical, chemical, and/or enzymatic means. Casein is one of the oldest natural polymers, used for adhesives, dating back to thousands years ago. Research on milk-protein-based adhesives is still ongoing. This article deals with the chemistry and structure of milk protein polymers, and examples of uses in environmentally-safe adhesives. These are promising routes in the exploration of the broad application of milk proteins.

A mussel-inspired double-crosslinked tissue adhesive intended for internal medical use

It has been a great challenge to develop aldehyde-free tissue adhesives that can function rapidly and controllably on wet internal tissues with fine adhesion strength, sound biocompatibility and degradability. To this end, we have devised a mussel-inspired easy-to-use double-crosslink tissue adhesive (DCTA) comprising a dopamine-conjugated gelatin macromer, a rapid crosslinker (namely, Fe(3+)), and a long-term acting crosslinker (namely, genipin). As a mussel-inspired gluing macromer, dopamine is grafted onto gelatin backbone via an one-step reaction, the catechol groups of which are capable of performing strong wet adhesion on tissue surfaces. By addition of genipin and Fe(3+), the formation of catechol-Fe(3+) complexation and accompanying spontaneous curing of genipin-primed covalent crosslinking of gluing macromers in one pot endows DCTA with the double-crosslink adhesion mechanism. Namely, the reversible catechol-Fe(3+) crosslinking executes an controllable and instant adhesive curing; while genipin-induced stable covalent crosslinking promises it with long-term effectiveness. This novel DCTA exhibits significantly higher wet tissue adhesion capability than the commercially available fibrin glue when applied on wet porcine skin and cartilage. In addition, this DCTA also demonstrates fine elasticity, sound biodegradability, and biocompatibility when contacting in vitro cultured cells and blood. In vivo biocompatibility and biodegradability are checked and confirmed via trials of subcutaneous implantation in nude mice model. This newly developed DCTA may be a highly promising product as a biological glue for internal medical use including internal tissue adhesion, sealing, and hemostasis.

STATEMENT OF SIGNIFICANCE

There is a great demand for ideal tissue adhesives that can be widely used in gluing wet internal tissues. Here, we have devised a mussel-inspired easy-to-use double-crosslink tissue adhesive (DCTA) that meets the conditions as an ideal tissue adhesive. It is composed of gelatin-dopamine conjugates - a gluing macromer, Fe(3+) - a rapid crosslinker, and genipin - a long-term acting crosslinker. This DCTA is constructed with a novel complexation-covalent double-crosslinking principle in one pot, in which the catechol-Fe(3+) crosslinking executes a controllable and instant adhesive curing, at the same time, genipin-induced covalent crosslinking promises it with long-term effectiveness in physiology conditions. This novel DCTA, with excellent wet tissue adhesion capability, fine elasticity, sound biodegradability, and biocompatibility, is a promising biological glue for internal medical use in surgical operations.

Effect of the Bioadhesive, BioGlue, on Impaired Colonic Anastomose Healing in Rats

Colonic anastomotic leakage is still a problem in general surgery practice. We sought to investigate the effect of a new tissue adhesive, BioGlue, on the healing of normal and impaired colonic anastomoses. Sixty-four rats were randomized into 4 groups. In all animals, a 1-cm segment of the left colon was resected, and an end-to-end sutured anastomosis was created. Animals were then divided into 2 groups: normal and impaired anastomosis. These 2 groups were further subdivided into 2 additional groups: animals that received BioGlue and those that did not. All rats received intraperitoneal injections of either 0.9% NaCl or 5-fluorouracil (5-FU). Anastomotic evaluation was done 7 days after surgery. Macroscopic healing, mechanical strength, and histopathologic healing parameters were evaluated. Leakage of the anastomosis was significantly higher in rats in the impaired group compared with those in the BioGlue groups (P = 0.043). The adhesion formation score was significantly higher in rats in the impaired anastomosis group compared with the other groups. Bursting pressures were significantly lower in the impaired anastomosis group than in the other ones (P = 0.001). Neoangiogenesis and fibroblast activity were different among the groups (P = 0.001). Inflammatory cell infiltration and collagen deposition did not differ among the groups (P = 0.07). Immediate postoperative intraperitoneal administration of 5-FU after colonic anastomosis inhibits intestinal wound healing. Covering colon anastomoses with BioGlue after suturing conferred beneficial effect on healing.

Use of biological Glue (Bioglue®) in laparoscopic partial nephrectomy: a study in pigs

Introduction

Partial nephrectomy is the standard of care for localized renal tumors. However, bleeding and warm ischemia time are still controversial when laparoscopic surgeries are carried out. Herein, we aim to compare the outcomes from laparoscopic partial nephrectomy with and without the use of biological glue with purified bovine albumin and glutaraldehyde (BioGlue®).

Materials and Methods

Twenty-four kidneys of 12 pigs were used in this study. A pre-determined lower pole segment was resected (3 cm x 1 cm) and one of two different hemostatic techniques was performed. In one kidney, hemostatic “U suture” (poliglecaprone 3.0) was performed and in the contra-lateral kidney, only the biological glue was applied. Data recorded was comprised of warm ischemia time (seconds) and estimated blood loss (mL) for each procedure. In cases of bleeding after glue administration, a complementary suture was done.

Results

Mean warm ischemia time was 492.9±113.1 (351-665) seconds and 746±185.3 (409-1125) seconds for biological glue and suture groups, respectively. There was a positive significant difference in terms of warm ischemia favoring the biological glue group over the suture group (p<0.001). Mean blood loss was 39.4 (0-115) mL for the biological glue group and 39.1 (5-120) mL for the suture group (p=0.62).

Conclusion

Biological glue is an important tool for laparoscopic partial nephrectomies. It is effective for hemostatic control in selected cases, and it can be used in combination with the traditional suture techniques.

Surgical Materials: Current Challenges and Nano-enabled Solutions

Surgical adhesive biomaterials have emerged as substitutes to sutures and staples in many clinical applications. Nano-enabled materials containing nanoparticles or having a distinct nanotopography have been utilized for generation of a new class of surgical materials with enhanced functionality. In this review, the state of the art in the development of conventional surgical adhesive biomaterials is critically reviewed and their shortcomings are outlined. Recent advancements in generation of nano-enabled surgical materials with their potential future applications are discussed. This review will open new avenues for the innovative development of the next generation of tissue adhesives, hemostats, and sealants with enhanced functionality for various surgical applications.

[The use of haemostatic agent: impact on perioperative outcomes of partial nephrectomy]

OBJECTIVE

To evaluate impact of the use of haemostatic agent in partial nephrectomy on perioperative outcomes.

MATERIAL AND METHODS

We reviewed the files of patients candidates for partial nephrectomy in our center between 2005 and 2010. The use of haemostatic agent and surgical procedure data were noted. Perioperative outcomes in haemostatic agent group were compared with perioperative outcomes in conventional surgical haemostasis group.

RESULTS

Among the 131 patients included, haemostatic agent was used in 91 cases (69.5%). There was no statistically difference between the two groups on age, sex, BMI, ASA score, tumor size and RENAL score. The use of haemostatic agent was more frequent for patients operated with laparoscopy (10.7%, P=0.04). Concerning perioperative outcomes, there was no difference between the two groups on surgical complications, transfusions, conversion to radical nephrectomy and hospital stay. Median warm ischaemia time was comparable into the two groups. In multivariate analysis, haemorrhage, complications and transfusions were not predicted by the use of haemostatic agent.

CONCLUSION

Use of haemostatic agent in partial nephrectomy had no benefice on perioperative outcomes in our series. Rapport between utility and cost for these agents must be discussed in partial nephrectomy.

Use of BioGlue Surgical Adhesive in Hypospadias Repair

PURPOSE

To prospectively evaluate the efficacy of albumin glutaraldehyde tissue adhesive (BioGlue) in the surgical treatment of patients with hypospadias.

MATERIALS AND METHODS

Two groups of 20 patients each who underwent hypospadias repair were included in the study. In the first group we utilized BioGlue as an additional protective layer to the suture line of the neo-urethra, while patients in the second group were operated on utilizing a routine surgical technique.

RESULTS

There were no statistical differences between patients from the 2 groups in terms of surgical complications. Urethrocutaneous fistula was revealed in 4 (20%) patients after repair with BioGlue and in 3 (15%) patients from the control group (p = 0.686), suture line breakdown in 4 (20%) and in 1 (5%) patients (p = 0.478), meatal stenosis in 1 (5%) and in 1 (5%) patient (p = 1). Furthermore more patients in the BioGlue group (n = 12, 60%) demonstrated poor cosmetic results compared to the control group where most patients - 19 (95%) had acceptable cosmetic outcomes (p = 0.007).

CONCLUSIONS

Our data showed no benefits of BioGlue use in hypospadias repair.

[The use of haemostatic agents in Urology]

Intra- and post-operative bleedings are frequent complications of all surgical procedures and can represent a severe risk for patients. Beginning from the second half of the 20th century, with an important spur from the development of laparoscopy, great efforts were made in the field of surgical research, aiming at improving hemostatic techniques. The development of mechanical and thermic hemostatic devices, in addition to the improvement of new suturing materials, already improved the possibility of bleeding control; yet a very important contribution in this field has been represented by the introduction in the surgical setting of chemical/biological agents capable of empowering locally blood hemostatic capacity. Currently, there are more chemical hemostatic agents surgeons can make use of in order to minimize bleedings: we reviewed the most important classes, considered their advantages, disadvantages and risks, and tried to look forward to those that will offer, in our view, the best options - for surgeons and patients - for an efficient and safe prevention and control of surgical bleedings, either in open or minimally invasive surgery.

BioGlue surgical adhesive as a thermal reflector during laparoscopic cryoablation: effect on iceball size and ablation zone diameter

In a porcine model, the application of BioGlue did not appear to increase the size of the iceball generated, nor did it change the amount of subjective bleeding noted.

Background and Objectives:

Cryoablation represents an alternative for treating small renal cortical neoplasms (RCN). Previously, we demonstrated that applying BioGlue during cryoablation diminished bleeding and incidentally noted that the iceballs seemed larger than those in controls. We examined the effects of BioGlue as a thermal insulator of cryoablated tissue to determine its effect on iceball size.

Methods:

Laparoscopic cryoablation (LCA) was performed in 6 female pigs (24 ablations) by using a single 1.47-mm cryoablation probe. One pole of each kidney was randomly treated with BioGlue prior to ablation, while the contralateral pole was the untreated control. The size of the iceball was measured using laparoscopic ultrasound. The tissue ablation zone was measured grossly after the specimens were harvested. We also documented the amount of bleeding on a subjective scale.

Results:

There were no differences in the diameters of the iceballs between the BioGlue and control groups when measured with laparoscopic ultrasound (P=.85). Similarly, the ablation zones on gross measurement were not significantly different (P=.47). No difference occurred in the amount of subjective bleeding.

Conclusions:

In a porcine model, the application of BioGlue prior to LCA does not appear to increase the size of the iceball generated. No change was observed in the amount of subjective bleeding as a result of using BioGlue.

Hemostasis in laparoscopic renal surgery

Hemorrhage is a potential risk at any step of laparoscopic nephrectomies (LNs). The advances in surgical equipment and tissue sealants have increased the safety and efficiency of performing LN and laparoscopic partial nephrectomy (LPN). However, hemostasis remains a major issue and there is still scope for further development to improve haemostatic techniques and devices. In this article a literature review of the current methods and techniques of hemostasis was carried out using the MEDLINE ^®/PubMed^® resources. The results of the review were categorized according to the three main operative steps: Dissection, control of renal pedicle and excision of the renal lesion.

Advancements in laparoscopic partial nephrectomy: expanding the feasibility of nephron-sparing

Partial nephrectomy (PN) offers equivalent oncologic outcomes to radical nephrectomy (RN) but has greater preservation of renal function and less risk of chronic kidney disease and cardiovascular disease. Laparoscopic PN remains underutilized likely because it is a technically challenging operation with higher rates of perioperative complications compared to open PN and laparoscopic RN. A review of the latest PN literature demonstrates that recent advancements in laparoscopic approaches, imaging modalities, ischemic mitigating strategies, renorrhaphy techniques, and hemostatic agents will likely allow greater utilization of LPN and expand its usage to increasingly more complex tumors.

[Partial elective nephrectomy]

INTRODUCTION

Partial nephrectomy is widely accepted as a therapeutic modality in renal cell carcinoma (RCC) in patients with single kidney, bilateral tumor or deteriorated renal function. Currently, long-term survival studies have consolidated partial nephrectomy as the treatment of choice for RCC in selected patients with normal contralateral kidney.

MATERIAL AND METHODS

Between July 1990 and January 2008, a total of 102 partial nephrectomy were performed on 100 patients with pre-operative ultrasonography diagnosis of renal carcinoma in 94 cases and complex renal cysts in 6 cases. The pre-operative ultrasonography size varied from 1.5 to 10 cm with an average of 4.85 cm.

RESULTS

Tumor size was correlated with the pathological stage, finding tumors in stage pT1 with sizes less than and greater than 4 cm in 74% and 64%, respectively, and in stage pT2 of 3.7% and 5.4%. Tumor size measured by pre-operative CT scan was compared with the definitive size of the pathology specimen in 93 cases (56<4 cm and 37>4 cm, according to the CT scan). We found high concordance, however in the larger tumors, there was a tendency of the CT scan to overestimate the size. A post-operative gamma scintigraphy with DMSA was performed in 40 patients. The values in the tumors <4 cm (21 patients) were 12-77% (average 43.3%). In tumors between 4 and 7 cm (17 patients), the values were 13.8-53.3% (average 37.6%) and in 2 cases of tumors >7 cm the post-operative DMSA showed 47.5 and 51%.

CONCLUSIONS

Partial nephrectomy is currently accepted as elective treatment in incidental kidney tumors less than 4 cm and it is indicated increasingly more frequently in larger tumors and of central localization. The finding of benign pathology in the anatomic-pathology specimen in up to 20% of the incidental renal tumors and low potential of malignancy of the possible satellite lesions in the remnant kidney also support nephron-sparing surgery in these tumors.

A new technique--"lipocorticoplasty"--for the closure of partial nephrectomy defects and its comparison with the standard technique

OBJECTIVE

We describe a new technique that can easily be used as a tension-free practical alternative in closing the renal defects resulting after open partial nephrectomy (PN).

METHODS

A new technique (called "lipocorticoplasty") where "wrapped fatty tissue" was placed in the tumor crater to close the renal defects that occur following PN is reported in 10 consecutive patients who underwent PN between May 2006 and January 2009 (Group I). Patients were compared with equal number of consecutive patients who underwent standard open PN before January 2009 (Group II) in terms of operative time, bleeding, tumor size, drain removal time, postoperative length of stay (PLOS), complications, and functional and oncological follow-up. Postoperative follow-up included physical examination, laboratory tests, and radiological screening at 3-month intervals for the first year, at 6-month intervals for the second year, and annually thereafter.

RESULTS

Mean tumor size (35.2 vs. 33.8 mm), operative time (156 vs. 165 min), bleeding (650 vs. 765 cc), drain removal time (2.8 vs. 2.5 POD), and PLOS (4.4 vs. 4.2 POD) were not statistically different between Group I and Group II, respectively. No intraoperative complications occurred. Postoperatively, transient complications without any permanent sequela were observed in 3 (1 in Group I and 2 in Group II) patients. Mean follow-up time was 16.1 months (7-26) in Group I and 19.1 months (8-36) in Group II. None of the patients had local or systemic recurrence at follow-up.

CONCLUSION

Our new technique provides obvious benefits in local hemostasis, simplifies parenchymal suturing, obviates the need for coaptation of the edges of the tumor bed defect under tension, and minimizes nephron loss due to kinking and tearing of renal parenchyma in the closure of the renal defects following open renal tumor excision.

Conservative treatment of persistent calyceal fistula after tumor excision. Case report and clinical remarks

Background

Nowadays, ultrasounds allow to discover accidentally a large number of renal small tumors. So, radical nephrectomy, which years ago was considered as the gold standard, is rarely required. Today, nephron sparing surgery is often prescribed for renal masses smaller than 4 cm. Its most frequent complication is calyceal fistula. It can be prevented exploring carefully the surgical surface, and suturing any opening. It can heal over within a few days or some weeks, so it can be a trouble for both the patient and the surgeon. A complete urinary drainage, obtained with an ureteral stent and an open bladder catheter, helps heal. Recently, it has become common practice to spread synthetic or biological tissue sealants over the surgical surface, to improve hemostasis. These surgical glues have also been used to repair calyceal openings, with conflicting results.

Methods

We performed left renal tumor excision (3.5 × 3 cm) in a 72-years-old man, during temporary renal artery occlusion with surface hypothermia. We placed intraoperatively an ureteral stent. The visual examination of the surgical cavity did not reveal any calyceal opening. We electrocauterized it and stuffed it with FloSeal. Surgical edges were free from illness. After 5 days urinary leakage from the drainage tube increased. Pyelography showed a calyceal fistula. A further stent was placed, with no results. Bladder catheter was kept open for about 2 months. Urinary leakage stopped 34 days after surgery.

Results

Urinary leakage increased when the catheter was removed, and stopped only after many days of complete urinary drainage.

Conclusions

The conservative treatment of a calyceal fistula must be considered a still effective therapy, also in difficult cases, provided that a complete and long-lasting urinary drainage is carried out.