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

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.

Pectin based biologic Velcro effectively seals traumatic solid organ and small bowel injuries

INTRODUCTION

Injuries to the liver and small bowel are common in multiple injuries. While there are currently a variety of accepted damage-control techniques to expeditiously manage such injuries, morbidity and mortality remain high. Pectin polymers have previously been shown to effectively seal visceral organ injuries ex vivo through physiochemical entanglement with the glycocalyx. We sought to compare the standard of care for the management of penetrating liver and small bowel injuries with a pectin-based bioadhesive patch in a live animal model.

METHODS

Fifteen adult male swine underwent a laparotomy with standardized laceration to the liver. Animals were randomized to one of three treatment arms: packing with laparotomy pads (n = 5), suture repair (n = 5), or pectin patch repair (n = 5). Following 2 hours of observation, fluid was evacuated from the abdominal cavity and weighed. Next, a full-thickness small bowel injury was created, and animals were randomized to either a sutured repair (n = 7) or pectin patch repair (n = 8). The segment of bowel was then pressurized with saline, and the burst pressure was recorded.

RESULTS

All animals survived the protocol to completion. There were no clinically significant differences between groups regarding baseline vitals or laboratory studies. On one-way analysis of variance, there was a statistically significant difference between groups regarding blood loss after liver repair (26 mL suture vs. 33 mL pectin vs. 142 mL packing, p < 0.01). On post hoc analysis, there was no statistically significant difference between suture and pectin ( p = 0.9). After repair, small bowel burst pressures were similar between pectin and suture repair (234 vs. 224 mm Hg, p = 0.7).

CONCLUSION

Pectin-based bioadhesive patches performed similarly to the standard of care for the management of liver lacerations and full-thickness bowel injuries. Further testing is warranted to assess the biodurability of a pectin patch repair, as it may offer a simple option to effectively temporize traumatic intra-abdominal injuries.

Functional Adhesion of Pectin Biopolymers to the Lung Visceral Pleura

Pleural injuries and the associated "air leak" are the most common complications after pulmonary surgery. Air leaks are the primary reason for prolonged chest tube use and increased hospital length of stay. Pectin, a plant-derived heteropolysaccharide, has been shown to be an air-tight sealant of pulmonary air leaks. Here, we investigate the morphologic and mechanical properties of pectin adhesion to the visceral pleural surface of the lung. After the application of high-methoxyl citrus pectin films to the murine lung, we used scanning electron microscopy to demonstrate intimate binding to the lung surface. To quantitatively assess pectin adhesion to the pleural surface, we used a custom adhesion test with force, distance, and time recordings. These assays demonstrated that pectin-glycocalyceal tensile adhesive strength was greater than nanocellulose fiber films or pressure-sensitive adhesives (p < 0.001). Simultaneous videomicroscopy recordings demonstrated that pectin-glycocalyceal adhesion was also stronger than the submesothelial connective tissue as avulsed surface remnants were visualized on the separated pectin films. Finally, pleural abrasion and hyaluronidase enzyme digestion confirmed that pectin binding was dependent on the pleural glycocalyx (p < 0.001). The results indicate that high methoxyl citrus pectin is a promising sealant for the treatment of pleural lung injuries.

Improved outcomes utilizing a novel pectin-based pleural sealant following acute lung injury

BACKGROUND

Persistent air leaks after thoracic trauma are associated with significant morbidity. To evaluate a novel pectin sealant in a swine model of traumatic air leaks, we compared a pectin biopolymer with standard surgical and fibrin-based interventions.

METHODS

A standardized lung injury was created in male Yorkshire swine. Interventions were randomized to stapled wedge resection (n = 5), topical fibrin glue (n = 5), fibrin patch (n = 5), and a pectin sealant (n = 6). Baseline, preintervention and postintervention tidal volumes (TV) were recorded. Early success was defined as the return to near-normal TV (>95% of baseline). Late success was defined as no detectable air leak in the chest tube after chest closure.

RESULTS

There were no differences in injury severity between groups (mean TV loss, 62 ± 17 mL, p = 0.2). Early success was appreciated in 100% (n = 6) of the pectin interventions which was significantly better than the fibrin sealant (20%, n = 1), fibrin patch (20%, n = 1), and stapled groups (80%, n = 4, p = 0.01). The percent of return to baseline TV after sealant intervention was significantly increased in the pectin (98%) and staple arms (97%) compared with the fibrin sealant (91%) and fibrin patch arms (90%) (p = 0.02; p = 0.03). Late success was also improved with the pectin sealant: no air leak was detected in 83% of the pectin group compared with 40% in the stapled group (p = 0.008)-90% of the fibrin-based interventions resulted in continuous air leaks (p = 0.001).

CONCLUSION

Pectin-based bioadhesives effectively seal traumatic air leaks upon application in a porcine model. Further testing is warranted as they may provide a superior parenchymal-sparing treatment option for traumatic air leaks.

Pressure-decay testing of pleural air leaks in intact murine lungs: evidence for peripheral airway regulation

The critical care management of pleural air leaks can be challenging in all patients, but particularly in patients on mechanical ventilation. To investigate the effect of central airway pressure and pleural pressure on pulmonary air leaks, we studied orotracheally intubated mice with pleural injuries. We used clinically relevant variables - namely, airway pressure and pleural pressure - to investigate flow through peripheral air leaks. The model studied the pleural injuries using a pressure-decay maneuver. The pressure-decay maneuver involved a 3 sec ramp to 30 cmH2 0 followed by a 3 sec breath hold. After pleural injury, the pressure-decay maneuver demonstrated a distinctive airway pressure time history. Peak inflation was followed by a rapid decrease to a lower plateau phase. The decay phase of the inflation maneuver was influenced by the injury area. The rate of pressure decline with multiple injuries (28 ± 8 cmH2 0/sec) was significantly greater than a single injury (12 ± 3 cmH2 O/sec) (P < 0.05). In contrast, the plateau phase pressure was independent of injury surface area, but dependent upon transpulmonary pressure. The mean plateau transpulmonary pressure was 18 ± 0.7 cm H2 O. Finally, analysis of the inflation ramp demonstrated that nearly all volume loss occurred at the end of inflation (P < 0.001). We conclude that the air flow through peripheral lung injuries was greatest at increased lung volumes and limited by peripheral airway closure. In addition to suggesting an intrinsic mechanism for limiting flow through peripheral air leaks, these findings suggest the utility of positive end-expiratory pressure and negative pleural pressure to maintain lung volumes in patients with pleural injuries.

Functional Mechanics of a Pectin-Based Pleural Sealant after Lung Injury

Pleural injury and associated air leaks are a major influence on patient morbidity and healthcare costs after lung surgery. Pectin, a plant-derived heteropolysaccharide, has recently demonstrated potential as an adhesive binding to the glycocalyx of visceral mesothelium. Since bioadhesion is a process likely involving the interpenetration of the pectin-based polymer with the glycocalyx, we predicted that the pectin-based polymer may also be an effective sealant for pleural injury. To explore the potential role of an equal (weight%) mixture of high-methoxyl pectin and carboxymethylcellulose as a pleural sealant, we compared the yield strength of the pectin-based polymer to commonly available surgical products. The pectin-based polymer demonstrated significantly greater adhesion to the lung pleura than the comparison products (p < 0.001). In a 25 g needle-induced lung injury model, pleural injury resulted in an air leak and a loss of airway pressures. After application of the pectin-based polymer, there was a restoration of airway pressure and no measurable air leak. Despite the application of large sheets (50 mm2) of the pectin-based polymer, multifrequency lung impedance studies demonstrated no significant increase in tissue damping (G) or hysteresivity (η)(p > 0.05). In 7-day survival experiments, the application of the pectin-based polymer after pleural injury was associated with no observable toxicity, 100% survival (N = 5), and restored lung function. We conclude that this pectin-based polymer is a strong and nontoxic bioadhesive with the potential for clinical application in the treatment of pleural injuries.

A prospective randomized trial comparing homologous and autologous fibrin sealants for the control of alveolar air leak

Background

Postoperative air leak is a common complication seen after pulmonary resection. It is a significant reason of morbidity and also leads to greater hospital cost owing to prolonged length of stay. The purpose of this study is to compare homologous sealant with autologous one to prevent air leak following pulmonary resection.

Methods

A total of 57 patients aged between 20 and 79 (mean age: 54.36) who underwent pulmonary resection other than pneumonectomy (lobar or sublobar resections) were analyzed. There were 47 males (83%) and 10 females (17%). Patients who intraoperatively had air leaks were randomized to receive homologous (Tisseel; n=28) or autologous (Vivostat; n=29) fibrin sealant. Differences among groups in terms of air leak, prolonged air leak, hospital stay, amount of air leak were analyzed.

Results

Indications for surgery were primary lung cancer in 42 patients (71.9%), secondary malignancy in 5 patients (8.8%), and benign disease in 10 patients (17.5%). Lobectomy was performed in 40 patients (70.2%), whereas 17 patients (29.8%) had wedge resection. Thirteen (46.4%) patients developed complications in patients receiving homologous sealant while 11 (38.0%) patients had complication in autologous sealant group (P=0.711). Median duration of air leak was 3 days in two groups. Time to intercostal drain removal was 3.39 and 3.38 days in homologous and autologous sealant group respectively (P=0.978). Mean hospital stay was 5.5 days in patients receiving homologous sealant whereas it was 5.0 days in patients who had autologous agent (P=0.140). There were no significant differences between groups in terms of measured maximum air leak (P=0.823) and mean air leak (P=0.186). There was no significant difference in the incidence of complications between two groups (P=0.711).

Conclusions

Autologous and heterologous fibrin sealants are safe and acts similarly in terms of air leak and hospital stay in patients who had resectional surgery.