Ablation of persistent air leaks after thoracic procedures with fibrin sealant

Injectable hydrogel based on dodecyl-modified N-carboxyethyl chitosan/oxidized konjac glucomannan effectively prevents bleeding and postoperative adhesions after partial hepatectomy

Hemostasis and prevention of postoperative adhesions after hepatectomy are still challenges. In this work, we chose chitosan, a competitive candidate hemostatic material, as the backbone, and konjac glucomannan as the functional moieties, to form an injectable hydrogel. The hydrogel was prepared by the Schiff base reaction of dodecyl-modified N-carboxyethyl chitosan (DCEC) and oxidized konjac glucomannan (OKGM), which could effectively prevent bleeding and postoperative adhesions. The resultant hydrogel possessed self-healing and tissue adhesive capability, and combined the unique bioactivities of two polysaccharides: DCEC endowed the hydrogel with excellent antibacterial and hemostatic ability by the electrostatic and hydrophobic interactions between the cell membrane and amine/dodecyl groups, and OKGM imparted hydrogel anti-inflammatory action by activating macrophages. Moreover, the notable hemostatic efficacy of the hydrogel was confirmed in a rat hepatectomy model. The hydrogel could prevent postoperative adhesions and down-regulate the inflammatory factor TNF-α and the pro-fibrotic factor TGF-β₁ in situ, which might be caused by the combination of the barrier function of hydrogel and instinct bioactivities of DCEC and OKGM. Thus, this multifunctional injectable hydrogel is potentially valuable for preventing bleeding and postoperative adhesions after hepatectomy.

Translational Applications of Hydrogels

Advances in hydrogel technology have unlocked unique and valuable capabilities that are being applied to a diverse set of translational applications. Hydrogels perform functions relevant to a range of biomedical purposes-they can deliver drugs or cells, regenerate hard and soft tissues, adhere to wet tissues, prevent bleeding, provide contrast during imaging, protect tissues or organs during radiotherapy, and improve the biocompatibility of medical implants. These capabilities make hydrogels useful for many distinct and pressing diseases and medical conditions and even for less conventional areas such as environmental engineering. In this review, we cover the major capabilities of hydrogels, with a focus on the novel benefits of injectable hydrogels, and how they relate to translational applications in medicine and the environment. We pay close attention to how the development of contemporary hydrogels requires extensive interdisciplinary collaboration to accomplish highly specific and complex biological tasks that range from cancer immunotherapy to tissue engineering to vaccination. We complement our discussion of preclinical and clinical development of hydrogels with mechanical design considerations needed for scaling injectable hydrogel technologies for clinical application. We anticipate that readers will gain a more complete picture of the expansive possibilities for hydrogels to make practical and impactful differences across numerous fields and biomedical applications.

Persistent air leak management in critically ill patients

Persistent air leak (PAL) is a challenging clinical entity, particularly in the setting of critical illness. It is a significant cause of morbidity, health care expenditure, and resource utilization. Data on its prevalence in the critically ill patient population are limited. Unique patient factors often necessitate an individualized approach. Guidelines on this subject are antiquated and do not specially address patients on mechanical ventilation. Critically ill patients may not be able to tolerate surgical intervention. Treatment in this population relies upon lung protective ventilation, various anecdotal modalities, chemical pleurodesis, autologous blood patching, and bronchoscopic insertion of endobronchial valves. Ventilation strategies center on rapid weaning and reduction of airway pressures. Anecdotal methods include implantable devices and chemical agents. Data on these modalities are limited to case reports. None have United States Food and Drug Administration (FDA) approval. The Spiration Valve System is FDA approved as a Humanitarian Device Exemption. Data on endobronchial valves are based on large case series, and only one small case series has focused exclusively on critically ill patients. The majority of valves in critically ill mechanically ventilated patients are used for non-FDA approved indications. Updated guidelines are desperately needed to ensure a standardized approach to this common clinical situation.

Management of air leaks post-surgical lung resection

Airleaks are one of the most common complications associated with elective lung resection. There have been many techniques and modern advancements in thoracic surgery, however airleaks persist. This review article will discuss several interventions ranging from conservative noninvasive to surgical management of the persistent airleak. These techniques include stopping of suction on the plueravac, fibrin patches, pleurodesis, use of endobronchial valves (EBVs), return to OR for operative intervention, and lastly to send patients home with mini pleuravacs.

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.

Management of Persistent Air Leaks

Alveolar-pleural fistulas causing persistent air leaks (PALs) are associated with prolonged hospital stays and high morbidity. Prior guidelines recommend surgical repair as the gold standard for treatment, albeit it is a solution with limited success. In patients who have recently undergone thoracic surgery or in whom surgery would be contraindicated based on the severity of illness, there has been a lack of treatment options. This review describes a brief history of treatment guidelines for PALs. In the past 20 years, newer and less invasive treatment options have been developed. Aside from supportive care, the literature includes anecdotal successful reports using fibrin sealants, ethanol injection, metal coils, and Watanabe spigots. More recently, larger studies have demonstrated success with chemical pleurodesis, autologous blood patch pleurodesis, and endobronchial valves. This manuscript describes these treatment options in detail, including postprocedural adverse events. Further research, including randomized controlled trials with comparison of these options, are needed, as is long-term follow-up for these interventions.

A Novel Technique to Treat Air Leak Following Lobectomy: Intrapleural Infusion of Plasma

Background

Persistent air leak following pulmonary lobectomy can be very difficult to treat and results in prolonged hospitalization. We aimed to evaluate the efficacy of a new method of postoperative air leak management using intrapleurally infused fresh frozen plasma via the chest tube.

Material/Methods

Between June 2008 and June 2014, we retrospectively reviewed 98 consecutive patients who underwent lobectomy for lung cancer and postoperatively developed persistent air leak treated with intrapleural instillation of fresh frozen plasma.

Results

The study identified 89 men and 9 women, with a median age of 65.5 years (range 48–77 years), with persistent postoperative air leak. Intrapleural infusion of fresh frozen plasma was successful in stopping air leaks in 90 patients (92%) within 24 hours, and in 96 patients (98%) within 48 hours, following resumption of the procedure. In the remaining 2, air leak ceased at 14 and 19 days.

Conclusions

Intrapleural infusion of fresh frozen plasma is a safe, inexpensive, and remarkably effective method for treatment of persistent air leak following lobectomy for lung cancer.

Bronchoscopic interventions for severe COPD

Chronic obstructive pulmonary disease (COPD) causes severe handicap among smokers. Most patients have to remain under continuous oxygen therapy at home. Moreover, respiratory infections are very common among these patients and vaccination is obligatory against influenza. Emphysema and bronchiectasis are observed with computed tomography (CT) and in several situations these parenchymal damages are responsible for pneumothorax in one case and pseudomonas aeroginosa infection. Novel mini-invasive techniques are used currently for emphysema treatments which are described extensively throughout our current work.

Successful treatment by fibrin glue sealant for pneumothorax with chronic GVHD resistant to autologous blood patch pleurodesis

Pneumothorax associated with chronic graft-versus-host disease (cGVHD) after stem cell transplantation is a rare complication. Autologous blood has been used successfully for pleurodesis, which was less toxic than chemical agents. However, when pneumothorax is resistant to pleurodesis, no other procedure is more effective and conservative. Here, we describe a case of myelodysplastic syndromes complicated with cGVHD-related pneumothorax. His pneumothorax has been resistant to pleurodesis using autologous blood and was treated successfully with fibrin glue sealant. In our limited experience, we believe the best success could be achieved when this method is used to treat persistent pneumothorax with cGVHD.

Autologous blood pleurodesis: A good choice in patients with persistent air leak

AIM

The study compares the efficiency, side effects and complications of autologous blood pleurodesis with talcum powder and tetracycline.

MATERIALS AND METHODS

This prospective study evaluated 50 patients with persistent air leak resulting from primary and secssondary spontaneous pneumothorax between February 2004 and March 2009. The patients inclussded 32 (64.0%) males and 18 (36.0%) females with a median age of 39 years (range 14-69 years). All cases had persistent air leak of more than seven days. Pleurodesis was performed using autologous blood in 20 (40.0%) patients, talc powder in 19 (38.0%) patients and tetracycline in 11 (22.0%) patients through a chest tube. Air leak cessation times after pleurodesis, side effects and pulmonary function tests (PFT) in the first and third months were measured.

RESULTS

Recurrent primary spontaneous pneumothorax was the cause of persistent air leak in all cases. Air leaks were expiratory only in 54.0% of cases. We obtained a success rate of 75.0% using autologous blood, 84.2% using talc powder and 63.6% using tetracycline. Mean air leak termination interval was significantly (P < 0.001) shorter in patients treated with autologous blood in comparison to talc powder and tetracycline. We observed a significant (P < 0.05) decline in PFT in patients treated with talc powder compared with tetracycline and autologous blood. Vital capacity, FVC and FEV₁were significantly lower in patients treated with tetracycline compared with autologous blood.

CONCLUSION

This study shows that autologous blood pleurodesis compared to talc powder and tetracycline is related with shorter leak cessation time and less pulmonary function decline in patients with persistent air leak. We think further randomized clinical trials of pleurodesis as treatment could increase its use in thorax surgery by demonstrating the safety and the efficacy of this procedure.

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.

Management of alveolar air leaks after pulmonary resection

Air leaks are a common problem after pulmonary resection and can be a source of significant morbidity and mortality. Air leaks are associated with prolonged hospital stays, and infectious and cardiopulmonary complications, and they occasionally require reoperation. Despite reasonably robust literature on the topic, the optimal approaches to manage postoperative air leaks remain controversial. We used available literature and expert consensus to formulate suggestions regarding the preferred approaches to both routine and prolonged alveolar air leaks. This review summarizes our findings.

A prospective, randomized, controlled trial of the effectiveness of BioGlue in treating alveolar air leaks

OBJECTIVE

The use of tissue glues has been advocated to reduce post-thoracotomy alveolar air leaks, but outcomes have been inconclusive. The aim of this study was to determine the effectiveness of BioGlue (CryoLife Europa Ltd, Hampshire, United Kingdom) in eliminating post-thoracotomy alveolar air leaks.

METHODS

A prospective, randomized, single-blind, controlled trial was conducted in which patients were stratified according to the severity of post-thoracotomy air leak that could not be controlled by conventional surgical techniques. They were allocated to a control arm (surgical treatment only) or an interventional arm (surgical treatment and BioGlue). Duration of air leak, intercostal drainage, and hospital stay comprised primary study end points.

RESULTS

From December 2002 to January 2005, 52 patients were randomized, 29 (56%) of whom were men. The mean age was 59 +/- 15 years, and other characteristics were comparable in both groups. Indications for surgery were malignancy in 46 patients (88%), carcinoid tumor in 2 patients (4%), and infective disease in 4 patients (8%). Patients in the BioGlue arm had shorter median duration of air leaks, 1 (0-2) versus 4 (2-6) days (P < .001); intercostal chest drainage, 4 (3-4) versus 5 (4-6) days (P = .012); and hospital stay, 6 (5-7) versus 7 (7-10) days (P = .004), compared with controls. No major complications were encountered using BioGlue.

CONCLUSIONS

This study demonstrates clear benefit from BioGlue in the treatment of alveolar air leaks through reduction of air leak duration, chest drainage time, and hospital stay. Systematic use of BioGlue may be warranted in adult thoracic surgical procedures (except pneumonectomy and decortication) when an air leak remains after all other steps to control it have failed.

Late-Onset Occult Pneumothorax After Lung Volume-Reduction Surgery

BACKGROUND

Lung volume-reduction surgery has proved to be a reliable palliative surgical treatment for patients with severe emphysema. Nonetheless, late complications can arise after lung volume-reduction surgery although this matter has been poorly investigated by previous studies.

METHODS

We report a series of 6 patients undergoing unilateral lung volume-reduction surgery at our institution between October 1995 and December 2004, who were readmitted several months after discharge because of the occurrence of occult pneumothorax mimicking acute respiratory failure.

RESULTS

Occult pneumothorax occurred in 3.3% of the 182 patients treated with lung volume-reduction surgery at our institution. Patients were readmitted after a mean of 94 days (range, 20 to 700 days) from the discharge. Chest roentgenography was unable to detect the occurrence of pneumothorax, which was instead revealed by means of a computed tomographic scan in all patients. The interval between admission and correct diagnosis averaged 22.4 hours. The number of air collections ranged between two and four. Treatment entailed solely blind chest drainage placement in 2 patients and awake video-assisted thoracoscopic surgery in the others, including placement of chest tube under direct vision in 1 patient, repair of lung tears by means of cyanoacrylate glue in 2 and bovine pericardium patch plus cyanoacrylate glue apposition in 1 patient.

CONCLUSIONS

In conclusion, we believe that occult pneumothorax should be kept in mind as one of the possible late complications of lung volume-reduction surgery and should be suspected whenever sudden worsening of dyspnea is noticed even in the presence of an uneventful chest roentgenogram. Awake video-assisted thoracoscopic surgery management can represent an effective option in these instances.

Fibrin glue in pulmonary resection: a prospective, randomized, blinded study

BACKGROUND

In contrast to the rare large-airway bronchopleural fistulas after lung resection, peripheral or alveolar air leaks (AAL) are very common, often prolong hospital stay, increase utilization of resources, and on occasion result in significant morbidity. Various adjuncts have been used in attempts to reduce AAL. One of these, the topical application of fibrin glue, has to date failed to demonstrate efficacy in small clinical trials. This study reexamines the role of fibrin glue in routine lobar and wedge pulmonary resections.

METHODS

Of 113 patients enrolled, 13 became ineligible because of intraoperative findings. The remaining 100 patients were randomly assigned to one of two groups at the conclusion of lung resection, regardless of the presence or absence of identifiable air leak. The control group received no additional intervention. The experimental group underwent application of 5 mL of fibrin glue delivered by a pressurized, aerosolized spraying mechanism. Postoperatively a blinded clinical observer recorded outcomes including the incidence and duration of AAL, prolonged AAL (PAAL), the volume of pleural drainage, the time to tube removal, and the postoperative length of stay (LOS), as well as any complications related to treatment.

RESULTS

Both groups were comparable with regard to demographics, diagnoses, and procedures. Statistically significant reductions were found in the experimental group in the overall incidence of AAL (34% versus 68%, p = 0.001), mean duration of AAL (1.1 versus 3.1 days, p = 0.005), mean time to chest tube removal (3.5 versus 5.0 days, p = 0.02), and the incidence of PAAL (2% versus 16%, p = 0.015). There was no significant difference in the volume of chest tube drainage or LOS (4.6 days glue and 4.9 days control, p = 0.318). There were no complications related to the use of fibrin glue.

CONCLUSIONS

Aerosolized fibrin glue appears to be safe and effective in reducing AAL. The overall incidence of AAL was reduced by 50% and PAAL occurred in only 1 treated patient (2% versus the usually reported 15%). Further studies with this and other methods are required to delineate routine versus selective use, to compare methods, and clarify cost benefit.

Cauterization versus fibrin glue for aerostasis in precision resections for secondary lung tumors

BACKGROUND

Aerostasis control in multiple resections for metastatic pulmonary diseases is a real problem. Long-term air leaks prolong postoperative hospitalization and result in an additional financial burden on the healthcare system. We focused our study on the evaluation of fibrin glue (Tissucol) as an effective means to minimize or prevent air leaks.

METHODS

We initiated a case-control study whereby 100 patients underwent precision resections for lung metastases. The subjects were divided into 2 groups, both with 50 patients: group 1 was treated with fibrin glue and group 2 with cauterization. Evaluation parameters consisted of the following: air leak duration, expected complications, drain time, and in-hospital stay.

RESULTS

In group 1, air-leak time was 2.68 +/- 1.72 days, versus 7.80 +/- 8.52 for group 2 (P <.001). In group 1, there were 2% complications, whereas in group 2 there were 28% (P <.001). Drain time was 4.54 +/- 1.83 days for group 1 and 9.54 +/- 8.35 for group 2 (P <.001). In-hospital stay was 6.54 +/- 1.83 days for group 1 and 11.54 +/- 8.35 for group 2 (P <.001).

CONCLUSIONS

In the group treated with fibrin glue, we observed significant advantages. Our experience shows that the use of fibrin glue can improve aerostasis control in nonanatomical resections with high risk of air leak.

Complications of lung volume reduction surgery

Lung volume reduction surgery (LVRS) continues to stimulate controversy and spirited discussion. The purpose of the operation is to palliate dyspnea and improve functional status and quality of life for highly selected patients with emphysema. The value of LVRS as a palliative procedure is clearly dependent on the surgeon's ability to minimize the frequency and severity of postoperative complications. This article investigates the sources of morbidity and mortality after LVRS and reports techniques to avoid and manage such complications.

Persistent air-leak following pulmonary resection

Air leaks are an unavoidable complication of pulmonary resection. The definition of a persistent air leak is arbitrary and may even be irrelevant in solving the problem. Persistent air leaks are more common in patients with severe COPD, and preoperative interventions are ineffective in reducing their prevalence. Meticulous surgical technique and care in handling and resection of the pulmonary parenchyma are essential in preventing persistent air leaks. Buttressing parenchymal staple lines and creating a pleural tent or pneumoperitoneum should be reserved for patients at risk for persistent air leaks. The use of currently available sealants is ineffective for the treatment of this complication. To stop persistent air leaks, early cessation of suction and placing chest tubes to an underwater seal is more effective than continuous suction. The management of persistent air leaks may require provocative chest tube clamping and permissive chest tube removal or patient discharge from the hospital with a chest tube and a Heimlich valve.

Intraoperative techniques to prevent air leaks

Persistent air leaks prolong chest tube duration and hospital stay after lung surgery. Air leaks also may lead to life-threatening empyemas. Preventing postoperative air leaks and BPFs is the best treatment for air-leak complications. Meticulous closure of parenchymal, pleural, and bronchial defects is the mainstay of air-leak control. The reinforcement of parenchymal suture and staple lines, pleural apposition, and well-vascularized tissue-flap coverage of bronchial suture and staple lines further reduce the incidence of prolonged air leaks and BPFs.

Predictors of alveolar air leaks

Persistent air leaks are caused by the failure of the postoperative lung to achieve a configuration that is physiologically amenable to healing. The raw pulmonary surface caused by the dissection of the fissure often is separated from the pleura, and the air leak fails to close. Additionally, higher air flow thorough an alveolar-pleural fistula seems to keep the fistula open. Other factors that interfere with wound healing, such as steroid use, diabetes, or malnutrition, can result in persistence of the leak. A thoracic surgeon can minimize the incidence of air leak through meticulous surgical technique and can identify patients in whom the balance of risks (Table 1) and benefits warrant operative intervention based on an understanding of the underlying pathophysiology.

Use of fibrin sealant for prosthetic mesh fixation in laparoscopic extraperitoneal inguinal hernia repair

OBJECTIVE

To evaluate the efficacy of mesh fixation with fibrin sealant (FS) in laparoscopic preperitoneal inguinal hernia repair and to compare it with stapled fixation.

SUMMARY BACKGROUND DATA

Laparoscopic hernia repair involves the fixation of the prosthetic mesh in the preperitoneal space with staples to avoid displacement leading to recurrence. The use of staples is associated with a small but significant number of complications, mainly nerve injury and hematomas. FS (Tisseel) is a biodegradable adhesive obtained by a combination of human-derived fibrinogen and thrombin, duplicating the last step of the coagulation cascade. It can be used as an alternative method of fixation.

METHODS

A prosthetic mesh was placed laparoscopically into the preperitoneal space in both groins in 25 female pigs and fixed with either FS or staples or left without fixation. The method of fixation was chosen by randomization. The pigs were killed after 12 days to assess early graft incorporation. The following outcome measures were evaluated: macroscopic findings, including graft alignment and motion, tensile strength between the grafts and surrounding tissues, and histologic findings (fibrous reaction and inflammatory response).

RESULTS

The procedures were completed laparoscopically in 49 sites. Eighteen grafts were fixed with FS and 16 with staples; 15 were not fixed. There was no significant difference in graft motion between the FS and stapled groups, but the nonfixed mesh had significantly more graft motion than in either of the fixed groups. There was no significant difference in median tensile strength between the FS and stapled groups. The tensile strength in the nonfixed group was significantly lower than the other two groups. FS triggered a significantly stronger fibrous reaction and inflammatory response than in the stapled and control groups. No infection related to method of fixation was observed in any group.

CONCLUSION

An adequate mesh fixation in the extraperitoneal inguinal area can be accomplished using FS. This method is mechanically equivalent to the fixation achieved by staples and superior to nonfixed grafts. Biologic soft fixation with FS will prevent early graft migration and will avoid the complications associated with staple use.

Fibrin sealant in preclinical and clinical studies

Fibrin sealant, now commercially available in the United States, is a virally inactivated preparation of highly purified human fibrinogen and human thrombin that includes aprotinin to reduce fibrinolysis. Although the product is relatively expensive, cost can be justified when the sealant is used to produce localized hemostasis in surgery in which bleeding cannot be controlled by sutures. Fibrin sealant can also be justified as an alternative to factor concentrates in patients with coagulopathies who have a localized site of bleeding. Newer formulations of fibrinogen and thrombin in a freeze-dried form applied as a bandage may be useful in immediate, on-site treatment of trauma victims in either a civilian or military setting.