Trial of a novel synthetic sealant in preventing air leaks after lung resection

Bioadhesive patch as a parenchymal sparing treatment of acute traumatic pulmonary air leaks

INTRODUCTION

Traumatic pulmonary injuries are common in chest trauma. Persistent air leaks occur in up to 46% of patients depending on injury severity. Prolonged leaks are associated with increased morbidity and cost. Prior work from our first-generation pectin patches successfully sealed pulmonary leaks in a cadaveric swine model. We now test the next-generation pectin patch against wedge resection in the management of air leaks in anesthetized swine.

METHODS

A continuous air leak of 10% to 20% percent was created to the anterior surface of the lung in intubated and sedated swine. Animals were treated with a two-ply pectin patch or stapled wedge resection (SW). Tidal volumes (TVs) were recorded preinjury and postinjury. Following repair, TVs were recorded, a chest tube was placed, and animals were observed for presence air leak at closure and for an additional 90 minutes while on positive pressure ventilation. Mann-Whitney U test and Fisher's exact test used to compare continuous and categorical data between groups.

RESULTS

Thirty-one animals underwent either SW (15) or pectin patch repair (PPR, 16). Baseline characteristics were similar between animals excepting baseline TV (SW, 10.3 mL/kg vs. PPR, 10.9 mL/kg; p = 0.03). There was no difference between groups for severity of injury based on percent of TV loss (SW, 15% vs. PPR, 14%; p = 0.5). There was no difference in TV between groups following repair (SW, 10.2 mL/kg vs. PPR, 10.2 mL/kg; p = 1) or at the end of observation (SW, 9.8 mL/kg vs. PPR, 10.2 mL/kg; p = 0.4). One-chamber intermittent air leaks were observed in three of the PPR animals, versus one in the SW group ( p = 0.6).

CONCLUSION

Pectin patches effectively sealed the lung following injury and were noninferior when compared with wedge resection for the management of acute traumatic air leaks. Pectin patches may offer a parenchymal sparing option for managing such injuries, although studies evaluating biodurability are needed.

Autologous mesenchymal stromal cells embedded with Tissucol Duo® for prevention of air leak after anatomical lung resection: results of a prospective phase I/II clinical trial with long-term follow-up

BACKGROUND

Prolonged air leak (PAL) is the most frequent complication after pulmonary resection. Several measures have been described to prevent the occurrence of PAL in high-risk patients, however, the potential role of mesenchymal stem cells (MSCs) applied in the parenchymal suture line to prevent postoperative air leak in this setting has not been fully addressed.

OBJECTIVE

To analyse the feasibility, safety and potential clinical efficacy of the implantation of autologous MSCs embedded in Tissucol Duo® as a prophylactic alternative to prevent postoperative prolonged air leak after pulmonary resection in high-risk patients.

STUDY DESIGN

Phase I/II single-arm prospective clinical trial.

METHODS

Six patients with high risk of PAL undergoing elective pulmonary resection were included. Autologous bone marrow-derived MSCs were expanded at our Good Manufacturing Practice (GMP) Facility and implanted (embedded in a Tissucol Duo® carrier) in the parenchymal suture line during pulmonary resection surgery. Patients were monitored in the early postoperative period and evaluated for possible complications or adverse reactions. In addition, all patients were followed-up to 5 years for clinical outcomes.

RESULTS

The median age of patients included was 66 years (range: 55-70 years), and male/female ratio was 5/1. Autologous MSCs were expanded in five cases, in one case MSCs expansion was insufficient. There were no adverse effects related to cell implantation. Regarding efficacy, median air leak duration was 0 days (range: 0-2 days). The incidence of PAL was nil. Radiologically, only one patient presented pneumothorax in the chest X-ray at discharge. No adverse effects related to the procedure were recorded during the follow-up.

CONCLUSIONS

The use of autologous MSCs for prevention of PAL in patients with high risk of PAL is feasible, safe and potentially effective.

TRIAL REGISTRATION NO

EudraCT: 2013-000535-27.

CLINICALTRIALS

gov idenfier: NCT02045745.

Reducing Post-Operative Alveolo-Pleural Fistula by Applying PGA-Sheets (Neoveil) after Major Lung Resection: A Historical Case-Control Study

Alveolo-pleural fistula remains a serious post-operative complication in lung cancer patients after surgery, which is associated with prolonged hospital stay and higher healthcare costs. The aim of this study is to evaluate the efficacy of a polyglycol acid (PGA)-sheet known as Neoveil in preventing post-operative air-leak in cases of detected intra-operative air-leak after lung resection. Between 11/2021 and 7/2022, a total of 329 non-small cell lung cancer (NSCLC) patients were surgically treated in two institutions. Major lung resections were performed in 251 cases. Among them, 44 patients with significant intra-operative air-leak at surgery were treated by reinforcing staple lines with Neoveil (study group). On the other hand, a historical group (selected by propensity score matched analysis) consisting of 44 lung cancer patients with significant intra-operative air leak treated by methods other than the application of sealant patches were considered as the control group. The presence of prolonged air-leak (primary endpoint), pleural drainage duration, hospital stay, and post-operative complication rates were evaluated. The results showed that prolonged air-leak (>5 days after surgery) was not observed in study group, while this event occurred in four patients (9.1%) in the control group. Additionally, a substantial reduction (despite not statistically significant) in the chest tube removal was noted in the study group with respect to the control group (3.5 vs. 4.5, p = 0.189). In addition, a significant decrease in hospital stay (4 vs. 6 days, p = 0.045) and a reduction in post-operative complications (2 vs. 10, p = 0.015) were observed in the study group when compared with the control group. Therefore, in cases associated with intra-operative air-leak after major lung resection, Neoveil was considered a safer and more effective aerostatic tool and represents a viable option during surgical procedures.

Medical Adhesives and Their Role in Laparoscopic Surgery—A Review of Literature

Laparoscopic surgery is undergoing rapid development. Replacing the traditional method of joining cut tissues with sutures or staples could greatly simplify and speed up laparoscopic procedures. This alternative could undoubtedly be adhesives. For decades, scientists have been working on a material to bond tissues together to create the best possible conditions for tissue regeneration. The results of research on tissue adhesives achieved over the past years show comparable treatment effects to traditional methods. Tissue adhesives are a good alternative to surgical sutures in wound closure. This article is a review of the most important groups of tissue adhesives including their properties and possible applications. Recent reports on the development of biological adhesives are also discussed.

A combination of polyglycolic acid fabric and fibrin glue prevents air leakage from a lung defect

OBJECTIVES

Air leakage after lung resection is a common morbidity that may lengthen hospital stay. Applying sealant to a lesion is an effective prophylaxis in clinical practice. This study aimed to examine the effect of a combination of a bioabsorbable polyglycolic acid (PGA) fabric and fibrin glue (FG) on air sealing by measuring the in vitro mechanical strength and degradation of the fabric, and in vivo histological changes after implantation.

METHODS

A defect was created in the canine left upper lung lobe, and then filled with a fibrinogen solution and covered with a PGA sheet spray-coated with fibrinogen and thrombin. After 1 and 4 weeks, air leakage from the lesion was examined in vivo under airway pressure. Tissue samples were harvested for histological assessment.

RESULTS

The mechanical strength of the PGA fabric remained at 80-90% of the baseline level for 1 week in phosphate-buffered saline, and then rapidly decreased to zero thereafter. Air leakage from the lung defect was prevented by the combination of PGA fabric and FG at 1 and 4 weeks. Histological examinations showed that PGA bundles persisted with a non-specific inflammatory response for 2 weeks and then gradually broke into sparse yarns surrounded by collagen fibres and capillaries by 8 weeks. The lung defect was filled with FG at 1 week and by granulation tissue thereafter.

CONCLUSIONS

These results provide evidence for the efficacy of a combination of PGA fabric and FG for the prevention of air leakage in the critical period after lung surgery.

Engineering a highly elastic bioadhesive for sealing soft and dynamic tissues

Injured tissues often require immediate closure to restore the normal functionality of the organ. In most cases, injuries are associated with trauma or various physical surgeries where different adhesive hydrogel materials are applied to close the wounds. However, these materials are typically toxic, have low elasticity, and lack strong adhesion especially to the wet tissues. In this study, a stretchable composite hydrogel consisting of gelatin methacrylol catechol (GelMAC) with ferric ions, and poly(ethylene glycol) diacrylate (PEGDA) was developed. The engineered material could adhere to the wet tissue surfaces through the chemical conjugation of catechol and methacrylate groups to the gelatin backbone. Moreover, the incorporation of PEGDA enhanced the elasticity of the bioadhesives. Our results showed that the physical properties and adhesion of the hydrogels could be tuned by changing the ratio of GelMAC/PEGDA. In addition, the in vitro toxicity tests confirmed the biocompatibility of the engineered bioadhesives. Finally, using an ex vivo lung incision model, we showed the potential application of the developed bioadhesives for sealing elastic tissues.

Efficacy of Intraoperative Hypertonic Glucose Solution Administration on Persistent Air Leak After Extended Pleurectomy/Decortication for Malignant Pleural Mesothelioma: A Retrospective Case-Control Study

Background

Persistent air leak is a common complication occurring from 6% to 23% of cases after extended pleurectomy/decortication for malignant pleural mesothelioma. Treatment options for this complication after major lung resection are well documented in literature; nevertheless, lines of evidence in extended pleurectomy/decortication for malignant pleural mesothelioma are absent. The aim of the study is to evaluate the efficacy of intraoperative administration of 50% hypertonic glucose solution in reducing duration of air leak following extended pleurectomy/decortication for malignant pleural mesothelioma.

Materials and Methods

In this retrospective case–control study, we analyzed our electronic health record and selected those patients with a histological diagnosis of malignant pleural mesothelioma who underwent extended pleurectomy/decortication in the period 2013–2021. From 2018, we introduced a lavage with 500 ml of glucose solution at 50% concentration into the chest cavity at the end of the surgical procedure. Patients operated before 2018 were used as the control group. Postoperative glycemia was measured, and patients were followed after hospital discharge until the air leak resolved and the chest tube was removed. Statistical analysis was performed using R software.

Results

A total of 71 patients met our criteria. Treatment and control groups were similar for age, sex, smoking status, number of comorbidities, tumor histotype, and side of disease. Use of hypertonic glucose solution resulted in shorter chest tube maintenance after hospital discharge (p = 0.0028). A statistically significant difference (p = 0.02) was also found in postoperative glycemia between the treatment (103 g/dl ± 8.9) and control group (98.8 g/dl ± 8.6). Days of hospitalization and chest tube maintenance during hospitalization did not significantly differ between the groups.

Interpretation

Intraoperative administration of 50% hypertonic glucose solution reduced the duration of air leak after hospital discharge. An increase in postoperative glycemia was found in the treatment group, but with no clinical effect. Hypertonic glucose solution is an effective and safe method to manage persistent air leak after extended pleurectomy/decortication for malignant pleural mesothelioma.

Local Effects of a 1940 nm Thulium-Doped Fiber Laser and a 1470 nm Diode Laser on the Pulmonary Parenchyma: An Experimental Study in a Pig Model

The lungs are a common site of metastases from malignant tumors. Their removal with a minimal but safe tissue margin is essential for the long-term survival of patients. The aim of this study was to evaluate the usefulness of a 1940 nm thulium-doped fiber laser (TDFL) and a 1470 nm diode laser (DL) in a pig model of lung surgery that involved the incision and excision of lung tissue. Histopathological analysis was performed on days 0 and 7 after surgery. Neither TDFL nor DL caused significant perioperative or postoperative bleeding. Histological analysis revealed the presence of carbonized necrotic tissue, mixed fibrin-cellular exudate in the superficial zone of thermal damage and bands of deeper thermal changes. The mean total width of thermal damage on day 0 was 499.46 ± 61.44 and 937.39 ± 109.65 µm for TDFL and DL, respectively. On day 7, cell activation and repair processes were visible. The total width of thermal damage was 2615.74 ± 487.17 µm for TDFL vs. 6500.34 ±1118.02 µm for DL. The superficial zone of thermal damage was narrower for TDFL on both days 0 and 7. The results confirm the effectiveness of both types of laser in cutting and providing hemostasis in the lungs. TDFL caused less thermal damage to the lung parenchyma than DL.

Development of alginate and gelatin-based pleural and tracheal sealants

Pleural and tracheal injuries remain significant problems, and an easy to use, effective pleural or tracheal sealant would be a significant advance. The major challenges are requirements for adherence, high strength and elasticity, dynamic durability, appropriate biodegradability, and lack of cell or systemic toxicity. We designed and evaluated two sealant materials comprised respectively of alginate methacrylate and of gelatin methacryloyl, each functionalized by conjugation with dopamine HCl. Both compounds are cross-linked into easily applied as pre-formed hydrogel patches or as in situ hydrogels formed at the wound site utilizing FDA-approved photo-initiators and oxidants. Material testing demonstrates appropriate adhesiveness, tensile strength, burst pressure, and elasticity with no significant cell toxicity in vitro assessments. Air-leak was absent after sealant application to experimentally-induced injuries in ex-vivo rat lung and tracheal models and in ex vivo pig lungs. Sustained repair of experimentally-induced pleural injury was observed for up to one month in vivo rat models and for up to 2 weeks in vivo rat tracheal injury models without obvious air leak or obvious toxicities. The alginate-based sealant worked best in a pre-formed hydrogel patch whereas the gelatin-based sealant worked best in an in situ formed hydrogel at the wound site thus providing two potential approaches. These studies provide a platform for further pre-clinical and potential clinical investigations. STATEMENT OF SIGNIFICANCE: Pneumothorax and pleural effusions resulting from trauma and a range of lung diseases and critical illnesses can result in lung collapse that can be immediately life-threatening or result in chronic leaking (bronchopleural fistula) that is currently difficult to manage. This leads to significantly increased morbidity, mortality, hospital stays, health care costs, and other complications. We have developed sealants originating from alginate and gelatin biomaterials, each functionalized by methacryloylation and by dopamine conjugation to have desired mechanical characteristics for use in pleural and tracheal injuries. The sealants are easily applied, non-cytotoxic, and perform well in vitro and in vivo model systems of lung and tracheal injuries. These initial proof of concept investigations provide a platform for further studies.

Drainless Thoracoscopic Lobectomy for Lung Cancer

OBJECTIVES: Drainless video-assisted thoracoscopic (VATS) wedge resection has been demonstrated as feasible in treating various lung diseases. However, it remains unknown whether this surgical technique can be effectively applied to lobectomy. In the current study, we evaluated the perioperative outcome of drainless, minimally invasive lobectomy in patients with lung cancer. METHODS: A total of 26 lung cancer patients who received surgery-performed pulmonary lobectomy were enrolled. The perioperative outcomes were analyzed based on a propensity score matching a comparison with those who had chest drainage. RESULTS: No major surgical morbidity and mortality was noted during the perioperative period. The mean of postoperative hospital stay was 5.08 ± 2.48 days. There was no significant difference in postoperative hospital stay between the two groups of patients. However, the presence of significant postoperative pain (VAS score > 30) on the first day after surgery was less in the drainless group (34.6% vs. 3.8%; p = 0.005). CONCLUSIONS: Our results demonstrated that drainless, minimally invasive lobectomy for selected lung cancer patients is feasible. Further evaluation of its impact on short- and long-term surgical outcomes is required in the future.

Engineering Hydrogel Adhesion for Biomedical Applications via Chemical Design of the Junction

Hydrogel adhesion inherently relies on engineering the contact surface at soft and hydrated interfaces. Upon contact, adhesion normally occurs through the formation of chemical or physical interactions between the disparate surfaces. The ability to form these adhesion junctions is challenging for hydrogels as the interfaces are wet and deformable and often contain low densities of functional groups. In this Review, we link the design of the binding chemistries or adhesion junctions, whether covalent, dynamic covalent, supramolecular, or physical, to the emergent adhesive properties of soft and hydrated interfaces. Wet adhesion is useful for bonding to or between tissues and implants for a range of biomedical applications. We highlight several recent and emerging adhesive hydrogels for use in biomedicine in the context of efficient junction design. The main focus is on engineering hydrogel adhesion through molecular design of the junctions to tailor the adhesion strength, reversibility, stability, and response to environmental stimuli.

Complications and Predictive Factors for Air Leak > 10 Days with Neoadjuvant Chemotherapy Followed by Pleurectomy/Decortication for Malignant Pleural Mesothelioma

BACKGROUND

A few studies have reported the incidence and clinical implications of complications after pleurectomy/decortication (P/D).

OBJECTIVE

The aim of this study was to assess the details of complications and predictive factors of particularly durable air leak with P/D.

METHODS

Data on 163 consecutive patients who underwent neoadjuvant chemotherapy (NAC) followed by P/D for malignant pleural mesothelioma between September 2012 and May 2020 at our institution were retrospectively analyzed. Postoperative complications and the significance of various preoperative risk factors for air leak > 10 days (AL10) to identify the group having a higher risk for particularly durable air leak were investigated. Risk factors for AL10 were sought using univariate and multivariate analyses.

RESULTS

Of 163 patients, 30- and 90-day mortality was 0.6% and 2.5%, respectively. Eighty-four (51.4%) patients experienced grade III or worse postoperative complications according to the Clavien-Dindo classification. The median duration of air leak was 7 postoperative days. AL10 occurred in 53 (32.5%) patients. Fifty-eight patients (35.6%) underwent pleurodesis and five patients (3.1%) underwent reoperation to control the air leak. On univariate analysis, performance status (PS; p = 0.003), prognostic nutritional index (p = 0.01), and pleural effusion (p = 0.04) were statistically significant risk factors for AL10, while on multivariate analysis, PS (odds ratio 4.0, 95% confidence interval 1.3-12.7; p = 0.02) remained the only variable predicted for AL10.

CONCLUSIONS

Recent postoperative mortality rates in NAC followed by P/D are quite acceptable. Approximately one in every three patients experienced AL10, and PS may be a risk factor associated with AL10.

A Prospective Study Investigating Blood Patch Pleurodesis for Postoperative Air Leaks After Pulmonary Resection

BACKGROUND

Prolonged air leaks (PALs) after lung resection are one of the most common complications in thoracic surgery. Several options are available to treat PALs. The autologous blood patch pleurodesis is commonly used but has not been thoroughly investigated.

MATERIALS AND METHODS

We conducted a prospective randomized study including all consecutive patients with PALs after pulmonary resections. Patients were randomized to either having received pleurodesis by injecting 100 mL autologous blood at d 5 and 6 (Group A) or being placed under observation (Group B). Patients from either group undergoing revisions were further investigated by a post hoc analysis and formed Group C.

RESULTS

A total of 24 patients were included: 10 patients were randomized to group A and 14 to group B. Six patients (3 from each group) underwent surgical revision and were included in Group C. Groups A and B did not differ in baseline characteristics. The median time to drainage removal was 9 d (range: 5-23 d) in Group A; 9 d (range: 2-20 d) in Group B; and 6 d in Group C (range: 3-10 d), (A/B versus C, P < 0.04; A versus B was not significant).

CONCLUSIONS

There is no evidence indicating a benefit for blood patch pleurodeses in patients undergoing lung resections and presenting with postoperative PALs for more than 5 d. An early operative closure of postoperative air leakage seems to be more effective.

Efficiency and safety of TachoSil® in the treatment of postoperative air leakage following pulmonary surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

There has been still no consensus whether to apply TachoSil® to reduce the incidence of air leakage after pulmonary surgery. We conducted this meta-analysis of randomized controlled trials (RCTs) to identify the efficiency and safety of TachoSil® applied in the prevention of postoperative air leakage following pulmonary surgery.

METHODS

We performed a systematic electronic search through EMABSE, PubMed and Web of Science up to March 2018. Summary risk ratio (RR) and weight mean difference (WMD) with corresponding 95% confidence intervals (CI) were calculated to analyze the outcomes. Fixed effect or random effect model was used to pool the estimates. Two independent reviewers assessed the quality of included studies using Cochrane risk-of-bias tool for RCTs.

RESULTS

We included six RCTs with a total of 921 patients. Compared with standard treatment (suturing, stapling techniques or electrocautery), TachoSil® was associated with the decreased air leak duration (WMD: -3.32 days; 95% CI: -5.34--1.31; P = 0.001), chest tube duration (WMD: -1.99 days; 95% CI: -3.14--0.84; P = 0.0007), hospital stay (WMD: -1.89 days; 95% CI: -2.42--1.35; P < 0.0001), and incidence of prolonged air leak (RR: 0.57; 95% CI: 0.35-0.92; P = 0.02). No significant difference was found between the two groups regarding the incidence of postoperative complications (RR: 0.86; 95% CI: 0.69-1.06; P = 0.16).

CONCLUSIONS

TachoSil® was safe, cost-effective and superior over standard treatment for patients who underwent pulmonary surgery in decreasing incidence of postoperative air leak, air leak duration, chest tube duration and the length of hospital stay.

Preclinical quantification of air leaks in a physiologic lung model: effects of ventilation modality and staple design

Purpose

Thoracic air leaks are a common complication following pulmonary resections. Limitations in clinical studies and preclinical models have hindered efforts to understand the pathophysiology of air leaks. With an emphasis on staple-line specific air leaks, we hypothesize that ventilation modality – intraoperative positive pressure vs postoperative negative pressure – and stapler design may play a role in air leaks.

Methods

Using a novel physiologic lung model, air leaks associated with graduated and uniform staple designs were evaluated under positive and negative pressure ventilation, simulating perioperative breathing in porcine lungs. Air leak incidence, air leak volume, and air leak rate were captured along with ventilation pressure and tidal volume.

Results

In all cases, negative pressure ventilation was associated with a higher occurrence of leaks when compared to positive pressure ventilation. Lungs leaked more air and at a faster rate under negative pressure ventilation compared to positive pressure ventilation. Graduated staple designs were associated with higher occurrence of leaks as well as larger leak rates when compared to uniform staples. Tissue thickness was not associated with differences in air leaks when tested with appropriate staple heights.

Conclusion

Using a novel lung model to investigate the pathophysiology of air leaks, we have identified breathing modality and staple design as two important variables that may impact air leaks. This work will help guide device design and drive future studies in human tissue, and it may help inform clinical practice to ultimately improve patient outcomes.

Extended pleurectomy decortication: the current role

Extended pleurectomy/decortication (EPD) has been formally defined but there remain technical areas of debate between practitioners. This is partly attributable to the relative rarity of this operation which is largely confined to a small number of specialist centres. Nevertheless, there is a widespread acceptance that extended pleurectomy/decortication (P/D) is a realistic and favourable alternative to extrapleural pneumonectomy. There may, however, remain a small number of clinical cases where this more extensive operation may be indicated. Preservation of the lung has widened the selection criteria for this form of radical mesothelioma surgery but there remain important factors to consider when offering extended P/D. In many patients with poorer prognostic factors the less radical operation of video assisted partial pleurectomy may be preferable. However, a randomized trial showed no survival benefit for this operation over simple talc pleurodesis. The future for P/D may also lie in the outcome of the MARS2 randomized controlled trial which will report in the next few years. Meanwhile there is a clinical and ethical dilemma when asked to perform this operation outside of the context of a clinical trial in the face of the lack of high grade evidence. The role of P/D is in one respect expanding but this may be short lived pending the findings of its assessment against non-surgical treatment.

Clinical outcomes of polymeric sealant use in pulmonary resection: a systematic review and meta-analysis of randomized controlled trials

Background

Prolonged alveolar air leak (PAL) is the most common adverse event following pulmonary resection. It carries morbidity for patients by increasing empyema risk, and for hospital administration with the cost of prolonged length of hospital stay (LOS). Intra-operative sealant technology is available to surgeons, and may decrease PAL. Our aim was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) on the effect of intraoperative polymeric sealant use on PAL, empyema, and LOS.

Methods

Standard PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analysis and methods) protocol was adhered to. For qualitative review the search strategy yielded 21 RCTs reporting polymeric sealant use in lung resection, 19 of which were included in meta-analyses. The control arm in the two excluded RCTs was not "standard care." Random-effects meta-analyses were conducted. Inter-trial heterogeneity was assessed with the I2 statistic. Publication bias was assessed with a funnel plot and Egger statistic for small study effects.

Results

Pooled analysis was derived from 2,537 randomized participants. They were allocated to the intervention arm of lung resection with intra-operative application of a polymeric sealant (n=1,292), or the control arm of standard care involving pulmonary resection with pneumostasis by sutures and/or stapler (n=1,245). Participants came from 10 different countries, with mean (SD) age of 62.5 (4.2) years, and 31.6% (95% CI: 30.0-33.5) female. Pooled estimates revealed polymeric sealant decreased odds of PAL (OR 0.55, 95% CI: 0.35-0.87), and decreased LOS by one day (mean difference -0.96, 95% CI: -1.74 to -0.18), without increasing odds of pleural sepsis (OR 1.134, 95% CI: 0.343-3.748). There was evidence of publication bias in the LOS meta-analysis.

Conclusions

Pooled analysis revealed decreased odds of PAL, and decreased LOS by one day with intraoperative use of polymeric sealants. There was no associated increase in odds of adverse events, including empyema.

Length of stay and hospitalization costs for patients undergoing lung surgery with Progel pleural air leak sealant

AIM

Progel Pleural Air Leak Sealant (Progel) is currently the only sealant approved by the FDA for the treatment of air leaks during lung surgery. This study was performed to determine whether Progel use improves hospital length of stay (LOS) and hospitalization costs compared with other synthetic/fibrin sealants in patients undergoing lung surgery.

METHODS

The US Premier hospital database was used to identify lung surgery discharges from January 1, 2010 to June 30, 2015. Eligible discharges were categorized as "Progel Sealant" or "other sealants" using hospital billing data. Propensity score matching (PSM) was performed to control for hospital and patient differences between study groups. Primary outcomes were hospital LOS and all-cause hospitalization costs. Clinical outcomes, hospital re-admissions, and sealant product use were also described.

RESULTS

After PSM, a total of 2,670 discharges were included in each study group; baseline characteristics were balanced between groups. The hospital LOS (mean days ± standard deviation, median) was significantly shorter for the Progel group (9.9 ± 9.6, 7.0) compared with the other sealants group (11.3 ± 12.8, 8.0; p < .001). Patients receiving Progel incurred significantly lower all-cause hospitalization costs ($31,954 ± $29,696, $23,904) compared with patients receiving other sealants ($36,147 ± $42,888, $24,702; p < .001).

LIMITATIONS

It is not possible to say that sealant type alone was responsible for the findings of this study, and analysis was restricted to the data available in the Premier database.

CONCLUSIONS

Among hospital discharges for lung surgery, Progel use was associated with significantly shorter hospital LOS and lower hospitalization costs compared with other synthetic/fibrin sealants, without compromising clinical outcomes.

Double-Cross-Linked Hydrogel Strengthened by UV Irradiation from a Hyperbranched PEG-Based Trifunctional Polymer

Conventional wound healing materials suffer from low efficiency, poor mechanical strength, and nontunable properties. Responsive hydrogels are appealing candidates for tissue engineering. Herein, we developed a double-cross-linked hydrogel system composed of hyperbranched PEG-based polymer, comprising pre-cross-linked acetal structure and numerous terminal acrylate groups, which can form hydrogels in situ and can be further strengthened by UV irradiation. The hyperbranched glycidyl methacrylate-co-poly(ethylene glycol) diacrylate polymers (HB-GMA-PEGs) were first synthesized via in situ deactivation enhanced atom transfer radical polymerization (DE-ATRP). A series of pre-cross-linked materials were achieved after postfunctionalization. The material can absorb a high amount of water to form hydrogels, and the gel stiffness was evaluated in detail before and after UV irradiation. The in vitro cytotoxicity experiments were conducted with the resulting materials and have demonstrated their good biocompatibility. The results indicate that this type of hydrogel with high water uptake capacity has appealing potential as a responsive biomaterial for wound closure.

3-D bioprinting technologies in tissue engineering and regenerative medicine: Current and future trends

Advances in three-dimensional (3D) printing have increased feasibility towards the synthesis of living tissues. Known as 3D bioprinting, this technology involves the precise layering of cells, biologic scaffolds, and growth factors with the goal of creating bioidentical tissue for a variety of uses. Early successes have demonstrated distinct advantages over conventional tissue engineering strategies. Not surprisingly, there are current challenges to address before 3D bioprinting becomes clinically relevant. Here we provide an overview of 3D bioprinting technology and discuss key advances, clinical applications, and current limitations. While 3D bioprinting is a relatively novel tissue engineering strategy, it holds great potential to play a key role in personalized medicine.

Engineering a highly elastic human protein-based sealant for surgical applications

Surgical sealants have been used for sealing or reconnecting ruptured tissues but often have low adhesion, inappropriate mechanical strength, cytotoxicity concerns, and poor performance in biological environments. To address these challenges, we engineered a biocompatible and highly elastic hydrogel sealant with tunable adhesion properties by photocrosslinking the recombinant human protein tropoelastin. The subcutaneous implantation of the methacryloyl-substituted tropoelastin (MeTro) sealant in rodents demonstrated low toxicity and controlled degradation. All animals survived surgical procedures with adequate blood circulation by using MeTro in an incisional model of artery sealing in rats, and animals showed normal breathing and lung function in a model of surgically induced rat lung leakage. In vivo experiments in a porcine model demonstrated complete sealing of severely leaking lung tissue in the absence of sutures or staples, with no clinical or sonographic signs of pneumothorax during 14 days of follow-up. The engineered MeTro sealant has high potential for clinical applications because of superior adhesion and mechanical properties compared to commercially available sealants, as well as opportunity for further optimization of the degradation rate to fit desired surgical applications on different tissues.

Local and systemic effects of fibrin and cyanoacrylate adhesives on lung lesions in rabbits

OBJECTIVES

Tissue adhesives can be used to prevent pulmonary air leaks, which frequently occur after lung interventions. The objective of this study is to evaluate local and systemic effects of fibrin and cyanoacrylate tissue adhesives on lung lesions in rabbits.

METHODS

Eighteen rabbits were submitted to videothoracoscopy + lung incision alone (control) or videothoracoscopy + lung incision + local application of fibrin or cyanoacrylate adhesive. Blood samples were collected and assessed for leukocyte, neutrophil and lymphocyte counts and interleukin-8 levels preoperatively and at 48 hours and 28 days post-operatively. After 28 days, the animals were euthanized for gross examination of the lung surface, and lung fragments were excised for histopathological analysis.

RESULTS

Fibrin and cyanoacrylate produced similar adhesion scores of the lung to the parietal pleura. Microscopic analysis revealed uniform low-cellular tissue infiltration in the fibrin group and an intense tissue reaction characterized by dense inflammatory infiltration of granulocytes, giant cells and necrosis in the cyanoacrylate group. No changes were detected in the leukocyte, neutrophil or lymphocyte count at any time-point, while the interleukin-8 levels were increased in the fibrin and cyanoacrylate groups after 48 hours compared with the pre-operative control levels (p<0.01).

CONCLUSION

Both adhesive agents promoted normal tissue healing, with a more pronounced local inflammatory reaction observed for cyanoacrylate. Among the serum markers of inflammation, only the interleukin-8 levels changed post-operatively, increasing after 48 hours and decreasing after 28 days to levels similar to those of the control group in both the fibrin and cyanoacrylate groups.

Low-voltage coagulation, polyglycolic acid sheets, and fibrin glue to control air leaks in lung surgery

OBJECTIVE

We evaluated the efficacy of low-voltage coagulation (LVC) with polyglycolic acid (PGA) sheets (Neoveil, GUNZE Ltd., Japan) and fibrin glue to control intraoperative alveolar air leaks after lung surgery.

METHODS

We included 176 patients with non-small cell lung cancer who underwent thoracoscopic lobectomies. When alveolar air leak was confirmed after lung resection, we applied LVC system to the pleural defect followed by layers of PGA sheets and fibrin glue (n = 40). We then analyzed postoperative air leaks (rate of occurrence and duration time).

RESULTS

73% of patients (29/40 cases) experienced no postoperative air leaks. Although 11 patients experienced air leaks after surgery, there were no prolonged air leaks (>7 days) (resolution time, 3.5 ± 1.4 days; range, 2-6 days). Two patients required drainage for late-onset air leaks, but their conditions improved without further treatment. There were no further adverse events.

CONCLUSIONS

The use of LVC with PGA sheets and fibrin glue following pulmonary resection efficiently prevented both intraoperative air leaks and prolonged air leaks after lung surgery.

Anticancer Therapeutic Alginate-Based Tissue Sealants for Lung Repair

Injury to the connective tissue that lines the lung, the pleura, or the lung itself can occur from many causes including trauma or surgery, as well as lung diseases or cancers. To address current limitations for patching lung injuries, to stop air or fluid leaks, an adherent hydrogel sealant patch system was developed, based on methacrylated alginate (AMA) and AMA dialdehyde (AMA-DA) blends, which is capable of sealing damaged tissues and sustaining physiological pressures. Methacrylation of alginate hydroxyl groups rendered the polysaccharide capable of photo-cross-linking when mixed with an eosin Y-based photoinitiator system and exposed to visible green light. Oxidation of alginate yields functional aldehyde groups capable of imine bond formation with proteins found in many tissues. The alginate-based patch system was rigorously tested on a custom burst pressure testing device. Blending of nonoxidized material with oxidized (aldehyde modified) alginates yielded patches with improved burst pressure performance and decreased delamination as compared with pure AMA. Human mesothelial cell (MeT-5A) viability and cytotoxicity were retained when cultured with the hydrogel patches. The release and bioactivity of doxorubicin-encapsulated submicrospheres enabled the fabrication of drug-eluting adhesive patches and were effective in decreasing human lung cancer cell (A549) viability.

Cost analysis of pulmonary lobectomy procedure: comparison of stapler versus precision dissection and sealant

OBJECTIVE

We aimed to evaluate the direct costs of pulmonary lobectomy hospitalization, comparing surgical techniques for the division of interlobar fissures: stapler (ST) versus electrocautery and hemostatic sealant patch (ES).

METHODS

The cost comparison analysis was based on the clinical pathway and drawn up by collecting the information available from the Thoracic Surgery Division medical team at Mantova Hospital. Direct resource consumption was derived from a previous randomized controlled trial including 40 patients. Use and maintenance of technology, equipment and operating room; administrative plus general costs; and 30-day use of postsurgery hospital resources were considered. The analysis was conducted from the hospital perspective.

RESULTS

On the average, a patient submitted to pulmonary lobectomy costs €9,744.29. This sum could vary from €9,027 (using ES) to €10,460 (using ST). The overall lower incidence (50% vs 95%, P=0.0001) and duration of air leakage (1.7 days vs 4.5 days, P=0.0001) in the ES group significantly affects the mean time of hospital stay (11.0 days vs 14.3 days) and costs. Cost saving in the ES group was also driven by the lower incidence of complications. The main key cost driver was staff employment (42%), then consumables (34%) and operating room costs (12%).

CONCLUSION

There is an overall saving of around €1,432.90 when using ES patch for each pulmonary lobectomy. Among patients undergoing this surgical procedure, ES can significantly reduce air leakage incidence and duration, as well as decrease hospitalization rates. However, further multicenter research should be developed considering different clinical and managerial settings.

Prospective evaluation of biodegradable polymeric sealant for intraoperative air leaks

Background

A biodegradable polymeric sealant has been previously shown to reduce postoperative air leaks after open pulmonary resection. The aim of this study was to evaluate safety and efficacy during minimally invasive pulmonary resection.

Methods

In a multicenter prospective single-arm trial, 112 patients with a median age of 69 years (range 34–87 years) were treated with sealant for at least one intraoperative air leak after standard methods of repair (sutures, staples or cautery) following minimally invasive pulmonary resection (Video-Assisted Thoracic Surgery (VATS) or Robotic-Assisted). Patients were followed in hospital and 1 month after surgery for procedure-related and device-related complications and presence of air leak.

Results

Forty patients had VATS and 72 patients had Robotic-Assisted procedures with the majority (80/112, 71%) undergoing anatomic resection (61 lobectomy, 13 segmentectomy, 6 bilobectomy). There were no device-related adverse events. The overall morbidity rate was 41% (46/112), with major complications occurring in 16.1% (18/112). In-hospital mortality and 30-day mortality were 1.9% (2/103). The majority of intraoperative air leaks (107/133, 81%) were sealed after sealant application, and an additional 16% (21/133) were considered reduced. Forty-nine percent of patients (55/112) were free of air leak throughout the entire postoperative study period. Median chest tube duration was 2 days (range 1 – 46 days), and median length of hospitalization was 3 days (range 1 – 20 days).

Conclusions

This study demonstrated that use of a biodegradable polymer for closure of intraoperative air leaks as an adjunct to standard methods is safe and effective following minimally invasive pulmonary resection.

Trial registration

ClinicalTrials.gov: NCT01867658. Registered 3 May 2013.

Efficacy and safety of Innoseal for air leak after pulmonary resection: a case-control study

BACKGROUND

Prolonged air leak is one of the most common complications after lung surgery and the cause of prolonged hospital stay frequently associated with major postoperative morbidity and thus responsible for even higher hospital costs. This case-control study was designed to test the sealing efficacy and safety of Enable-Innoseal TP4 in patients undergoing pulmonary resection for lung cancer.

METHODS

This was a case-control trial enrolling patients with primary or single site metastatic lung cancer scheduled for elective anatomic or nonanatomic pulmonary resection presenting intraoperative grade 1 or 2 air leak at water submersion test; the study group population was then matched 1:1 according to surgical procedure, male/female ratio, preoperative FEV1, and age.

RESULTS

In the study population, 21 patients (70.0%) presented intraoperative grade 1 air leak and 9 patients grade 2 (30.0%) air leak; after comparison with the control group, we observed a significant shorter time for chest drain removal in the study population (P = 0.0050), whereas no difference was registered in terms of number of days needing for discharge (P = 0.0762).

CONCLUSIONS

Enable-Innoseal TP4 was effective in treating limited intraoperative air leaks after pulmonary resection and preventing prolonged postoperative air leaks in patients receiving either anatomic or nonanatomic lung resections. Further randomized double-arm studies are required to confirm the efficacy of Enable-Innoseal TP4 demonstrated by this pilot study.

Elastic sealants for surgical applications

Sealants have emerged as promising candidates for replacing sutures and staples to prevent air and liquid leakages during and after the surgeries. Their physical properties and adhesion strength to seal the wound area without limiting the tissue movement and function are key factors in their successful implementation in clinical practice. In this contribution, the advances in the development of elastic sealants formed from synthetic and natural materials are critically reviewed and their shortcomings are pointed out. In addition, we highlight the applications in which elasticity of the sealant is critical and outline the limitations of the currently available sealants. This review will provide insights for the development of novel bioadhesives with advanced functionality for surgical applications.

Clinical applications of surgical adhesives and sealants

In the United States and Europe, the number of topical adhesives, surgical sealants, and hemostats approved for use in the surgical setting is ever expanding although no single device fills all medical and surgical needs to replace sutures. As more surgical procedures are performed through laparoscopic and robotic approaches, these devices are becoming more important, and current research is focused on solving the limitations of conventional wound treatments. This review article discusses clinical applications of various biologically derived and synthetic products that are currently available to surgeons and those that are in development.

Controlling air leaks using free pericardial fat pads as surgical sealant in pulmonary resection

BACKGROUND

This study evaluated the feasibility and efficacy of a new operative method for controlling intraoperative air leaks using free pericardial fat pads as a covering sealant in pulmonary resection.

METHODS

To manage air leaks that must be controlled in pulmonary resection at the first water sealing test, collected free pericardial fat was used as a covering sealant and sewn on by the suture closing the lesion. In cases of uncontrolled air leaks at the second sealing test, fibrin glue was used to fill the residual lesion between the fat and visceral pleura. Fifty-one eligible patients were enrolled in this study to evaluate the duration of postoperative air leaks and the condition of the implanted fat on chest computed tomography (CT) 6 months later.

RESULTS

The mean duration of postoperative air leaks was 1.05 ± 1.84 days in the 39 cases that received the pericardial fat covering technique only and 2.66 ± 3.42 days in the 12 cases that received the pericardial fat covering technique combined with fibrin glue. Prolonged alveolar air leaks occurred in 1 case and 2 cases, respectively. No cases required conversion to conventional methods, and there were no further adverse events. On follow-up chest CT approximately 62.7% of obvious engrafted fat survived.

CONCLUSIONS

Using free pericardial fat pads as a sealant to control air leaks in pulmonary resection is safe and has good feasibility and potent efficacy. This new method can be an innovative technique for preventing prolonged air leaks.

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.

Tuning model drug release and soft-tissue bioadhesion of polyester films by plasma post-treatment

Plasma treatments are investigated as a post-production method of tuning drug release and bioadhesion of poly(lactic-co-glycolic acid) (PLGA) thin films. PLGA films were treated under varying conditions by controlling gas flow rate, composition, treatment time, and radio frequency (RF) power. In vitro release of the drug-like molecule fluorescein diacetate (FDAc) from plasma-treated PLGA was tunable by controlling RF power; an increase of 65% cumulative release is reported compared to controls. Bioadhesion was sensitive to RF power and treatment time, assessed using ex vivo shear-stress tests with wetted swine aorta. We report a maximum bioadhesion ∼6-fold that of controls and 5-fold that of DOPA-based mussel adhesives tested to swine skin.1 The novelty of this post-treatment is the activation of a hydrophobic polyester film for bioadhesion, which can be quenched, while simultaneously tuning drug-release kinetics. This exemplifies the promise of plasma post-treatment for in-clinic bioadhesive activation, along with technological advancements, i.e., atmospheric plasma and hand-held "plasma pencils".

In Situ Deposition of PLGA Nanofibers via Solution Blow Spinning

Nanofiber mats and scaffolds have been widely investigated for biomedical applications. Commonly fabricated using electrospinning, nanofibers are generated ex situ using an apparatus that requires high voltages and an electrically conductive target. We report the use of solution blow spinning to generate conformal nanofiber mats/meshes on any surface in situ, utilizing only a commercial airbrush and compressed CO₂. Solution and deposition conditions of PLGA nanofibers were optimized and mechanical properties characterized with dynamic mechanical analysis. Nanofiber mat degradation was monitored for morphologic and molecular weight changes in vitro. Biocompatibility of the direct deposition of nanofibers onto two cell lines was demonstrated in vitro and interaction with blood was qualitatively assessed with scanning electron microscopy. A pilot animal study illustrated the wide potential of this technique across multiple surgical applications, including its use as a surgical sealant, hemostatic, and buttress for tissue repair.

Use of energy-based coagulative fusion technology and lung sealants during anatomic lung resection

OBJECTIVES

Energy-based tissue fusion technology is being increasingly used for vascular division in numerous intra-abdominal applications. Very few data, however, are available regarding the application of this technology in the chest during anatomic lung resection. In the present review, we evaluated the use of energy-based fusion and lung sealants during anatomic lung resection.

METHODS

We performed a review of case series and published studies to evaluate the use of energy-based coagulative fusion technology and lung sealants during anatomic lung resection. We then used energy-based coagulative fusion technology during anatomic lung resection (segmentectomy or lobectomy) in 316 cases from 2008 to 2011. Two energy applications were applied to the arterial and venous branches before vessel division.

RESULTS

In the first 12 cases, we used a device with a small curved jaw (range, 3.3-4.7 mm). Two partial venous dehiscences were noted and controlled intraoperatively. For the remaining cases, we used a larger jaw (6 mm × 22 mm) with no arterial or venous dehiscence occurring (vessels ranged from 0.4 to 1.2 cm). Autologous or synthetic tissue sealants applied to the parenchymal staple lines might reduce the severity and duration of perioperative air leaks. Suture line buttressing with pericardial or absorbable biosynthetic polyester strips might reduce the severity of air leaks in patients with severe emphysema undergoing anatomic lung resection or lung volume reduction surgery.

CONCLUSIONS

The bipolar tissue fusion system provides a safe and effective technique for the division of the pulmonary arterial and venous branches during anatomic lung resection. Surgical sealants and buttressing adjuncts might reduce perioperative air leak potential.

TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

Background

Controversies surrounding the efficacy of surgical sealants against alveolar air leaks (AAL) in lung surgery abound in the literature. We sought to test the sealing efficacy of a novel synthetic sealant, TissuePatch™ in an in vitro lung model.

Methods

The lower lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A superficial parenchymal defect (40 × 25 mm) was created, followed by AAL assessment. After sealant application, AAL was assessed again until burst failure occurred. The length of defect was recorded to evaluate the elasticity of the sealant.

Results

Superficial parenchymal defects resulted in AAL increasing disproportionally with ascending maximal inspiratory pressure (Pmax). Multiple linear regression analysis revealed strong correlation between AAL and Pmax, compliance, resistance. After sealant application, AAL was sealed in all ten tests at an inspired tidal volume (TVi) of 400 ml, in nine tests at TVi = 500 ml, in seven at TVi = 600 ml and in five at TVi = 700 ml. The mean burst pressure was 42 ± 9 mBar. Adhesive and cohesive sealant failures were found in six and three tests respectively. The length of defect before sealant failure was 8.9 ± 4.9% larger than that at TVi = 400 ml, demonstrating an adequate elasticity of this sealant film.

Conclusions

TissuePatch™ may be a reliable sealant for alternative or adjunctive treatment for repair of superficial parenchymal defects in lung surgery. The clinical benefits of this sealant should be confirmed by prospective, randomised controlled clinical trials.

Abstrakt

Methode

Der Unterlappen von frisch entnommenen Schweinlungen (n = 10) wurde intubiert und beatmet. Eine pleurale Läsion (40 × 25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen.

Ergebnis

Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi = 400 ml in allen zehn Testen versiegelt, bei TVi = 500 ml in neun Testen, bei TVi = 600 ml in sieben und bei TVi = 700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42 ± 9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9 ± 4,9% größer als die bei TVi = 400 ml.

Schlussfolgerung

Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden.

TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

BACKGROUND

Controversies surrounding the efficacy of surgical sealants against alveolar air leaks (AAL) in lung surgery abound in the literature. We sought to test the sealing efficacy of a novel synthetic sealant, TissuePatch™ in an in vitro lung model.

METHODS

The lower lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A superficial parenchymal defect (40 × 25 mm) was created, followed by AAL assessment. After sealant application, AAL was assessed again until burst failure occurred. The length of defect was recorded to evaluate the elasticity of the sealant.

RESULTS

Superficial parenchymal defects resulted in AAL increasing disproportionally with ascending maximal inspiratory pressure (Pmax). Multiple linear regression analysis revealed strong correlation between AAL and Pmax, compliance, resistance. After sealant application, AAL was sealed in all ten tests at an inspired tidal volume (TVi) of 400 ml, in nine tests at TVi = 500 ml, in seven at TVi = 600 ml and in five at TVi = 700 ml. The mean burst pressure was 42 ± 9 mBar. Adhesive and cohesive sealant failures were found in six and three tests respectively. The length of defect before sealant failure was 8.9 ± 4.9% larger than that at TVi = 400 ml, demonstrating an adequate elasticity of this sealant film.

CONCLUSIONS

TissuePatch™ may be a reliable sealant for alternative or adjunctive treatment for repair of superficial parenchymal defects in lung surgery. The clinical benefits of this sealant should be confirmed by prospective, randomised controlled clinical trials. ABSTRAKT:

HINTERGRUND

Die Wirksamkeit von chirurgischen Klebstoffen zur Prävention von alveolo-pleuralem Luftleck (APL) ist trotz zunehmenden klinischen Anwendungen in Lungenchirurgie immer noch kontrovers diskutiert. Wir evaluierten die Abdichtungswirksamkeit von einem neuartigen synthetischen Kleber, TissuePatch™ mittels eines in vitro Lungenmodels. METHODE: Der Unterlappen von frisch entnommenen Schweinlungen (n = 10) wurde intubiert und beatmet. Eine pleurale Läsion (40 × 25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen. ERGEBNIS: Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi = 400 ml in allen zehn Testen versiegelt, bei TVi = 500 ml in neun Testen, bei TVi = 600 ml in sieben und bei TVi = 700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42 ± 9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9 ± 4,9% größer als die bei TVi = 400 ml.

SCHLUSSFOLGERUNG

Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden.

A novel approach to control air leaks in complex lung surgery: a retrospective review

Background

Intra-operative air leaks (IOAL) are common complications of pulmonary surgery. The post-operative management of air leaks requires a chest tube which may lead to longer hospitalization, further medical complications, and increased costs. Sealants have been shown to help control intra-operative air leaks and studies have demonstrated a reduction in chest tube duration and/or length of hospital stay. Nevertheless, systematic reviews have not presented sufficient evidence to recommend their general use in lung resection.

Methods

One hundred and twenty-one consecutive patients who underwent pulmonary surgery with and without Progel® Pleural Air Leak Sealant were reviewed retrospectively. Intra-operative and 3-months postoperative data were assessed for the presence and persistence of air leaks, chest tube duration, the length of hospital stay, and complications.

Results

Seventy patients (57.9%) had IOAL. Thirty-six were treated with Progel in addition to standard intra-operative technique (pleural-sealant group; PSG) and 34 patients were treated only with standard technique (control group; CG). The percentage of post-operative air leaks in the PSG was 11% (1.2% >Grade 2 air leak) compared with 58.8% (6% >Grade 2 air leak) in the CG (p <0.0001, Leaks graded from 1 = small air leak to 7 = large air leak). The median chest tube duration was significantly shorter in the PSG compared with the controls (1.0 versus 2.5 days; p < 0.0001). The median length of hospital stay was 50% lower in the PSG compared with the control group (1.5 versus 3.0 days; p = 0.047). There were no significant differences in complications between the two groups.

Conclusions

The results of this single-center, single surgeon, retrospective review demonstrate a significant reduction in IOAL, chest tube duration, and length of hospital stay in the in patients treated with Progel when compared with standard intra-operative closure management alone. They suggest that the use of a pleural sealant is more effective in reducing alveolar air leaks associated with lung resection compared with standard closure techniques alone and may result in both an improved surgical outcome and a reduction in costs associated with prolonged hospital stay.

Is Acrylate Co-monomer (Glubran-2) Useful in the Prevention of Prolonged Air Leaks After Pulmonary Lobectomy?

Many synthetic materials are being used in order to reduce the frequency of prolonged air leak (PAL) in thoracic surgical practice. This study presents our experience with the topical application of acrylate co-monomer (Glubran-2) as a synthetic tissue adhesive in an attempt to decrease troublesome postoperative air leaks in patients undergoing resection for non-small cell lung carcinoma. Of the 112 patients who had undergone resection for lung carcinoma, 69 patients having lobectomy or bilobectomy were included in this study. The application group (group A) consisted of 33 patients where a synthetic tissue adhesive (Glubran-2) was used and compared with the control group (group C, n = 36) retrospectively. There was no difference between the groups regarding demographic details and operative variables. Both groups were compared in view to PAL, chest tube duration, in-hospital stay and hospital costs. There was no significant difference between group A (n = 11, 33 %) and group C (n = 6, 17 %) for the development of PAL (P = 0.11). Hospital stay was 16.1 ± 6.7 days in group A and 15.3 ± 5.8 days in group C (P = 0.66). The surgical cost was significantly higher in group A (€806 ± 127) than the group C (€624 ± 94) (P < 0.001). There was no significant difference between the groups regarding overall hospital costs (P = 0.41). In this study, the use of Glubran-2 following lung resection for non-small cell lung carcinoma did not decrease the incidence of PAL. Neither did it have a favorable effect concerning in-hospital stay nor did it decrease overall hospital costs while increasing surgical costs as expected.

Photoactivated composite biomaterial for soft tissue restoration in rodents and in humans

Soft tissue reconstruction often requires multiple surgical procedures that can result in scars and disfiguration. Facial soft tissue reconstruction represents a clinical challenge because even subtle deformities can severely affect an individual's social and psychological function. We therefore developed a biosynthetic soft tissue replacement composed of poly(ethylene glycol) (PEG) and hyaluronic acid (HA) that can be injected and photocrosslinked in situ with transdermal light exposure. Modulating the ratio of synthetic to biological polymer allowed us to tune implant elasticity and volume persistence. In a small-animal model, implanted photocrosslinked PEG-HA showed a dose-dependent relationship between increasing PEG concentration and enhanced implant volume persistence. In direct comparison with commercial HA injections, the PEG-HA implants maintained significantly greater average volumes and heights. Reversibility of the implant volume was achieved with hyaluronidase injection. Pilot clinical testing in human patients confirmed the feasibility of the transdermal photocrosslinking approach for implantation in abdomen soft tissue, although an inflammatory response was observed surrounding some of the materials.

Safety and effectiveness of a new fibrin pleural air leak sealant: a multicenter, controlled, prospective, parallel-group, randomized clinical trial

BACKGROUND

This study evaluated the sealing capacity and safety of a new fibrin sealant (FS) to reduce alveolar air leaks (AALs) after pulmonary resections in a randomized controlled clinical trial conducted in 3 Italian centers.

METHODS

The study randomized (1:1) 185 patients with an intraoperative AAL graded 1 to 3 according to the Macchiarini scale: 91 received FS and 94 had standard lung closure. The primary outcomes were the length of postoperative AAL duration and the mean time to chest drain removal. Other end points included the percentage of patients without AAL, the development of serum antibodies against bovine aprotinin, and any adverse event related to FS. Chest drains were removed when fluid output was 100 mL/day or less, with no air leak.

RESULTS

The study groups were comparable with respect to demographic variables and surgical procedures. The FS group showed a statistically significant reduction in duration of postoperative AALs (9.52 vs 35.8 hours; p < 0.005) and in the percentage of patients with AALs at wound closure (81.11% vs 100%; p < 0.001); the difference in time to chest drain removal was not significant. Pleural empyema developed in 1 patient with FS treatment vs in 4 with standard treatment, and antibodies against bovine aprotinin were found in 34 of 91 FS-treated patients.

CONCLUSIONS

The present study showed that the new FS is safe and effective in preventing AALs after lung resections and in shortening the duration of postoperative AALs.

Evidence-based suggestions for management of air leaks

The management of postoperative alveolar air leaks (AALs) continues to challenge thoracic surgeons. AALs increase length of stay and health care costs, and likely lead to other postoperative complications. Staple line buttresses, topical sealants, pleural tents, pneumoperitoneum, and modifications of traditional chest tube management (ie, reduced suction) have all been proposed to help reduce AAL. However, the cost of some of the commercial products being marketed may outweigh their relative effectiveness, and some of these techniques and products have not been adequately studied to date. This article provides a review of the available evidence-based literature that addresses the efficacy of the options currently available to prevent and manage AALs. Management suggestions based on this literature are presented.