Porcine small intestine submucosal grafts improve remucosalization and progenitor cell recruitment to sites of upper airway tissue remodeling

Promotion of diced cartilage survival and regeneration with grafting of small intestinal submucosa loaded with urine-derived stem cells

Cartilage absorption and calcification are prone to occur after the implantation of diced cartilage wrapped with autologous materials, as well as prolong the operation time, aggravate surgical trauma and postoperative pain during the acquisition process. Small intestinal submucosa (SIS) has suitable toughness and excellent degradability, which has been widely used in the clinic. Urine-derived stem cells (USCs), as a new type of stem cells, have multi-directional differentiation potential. In this study, we attempt to create the tissue engineering membrane material, termed USCs-SIS (U-SIS), and wrap the diced cartilage with it, assuming that they can promote the survival and regeneration of cartilage. In this study, after co-culture with the SIS and U-SIS, the proliferation, migration and chondrogenesis ability of the auricular-derived chondrocyte cells (ACs) were significantly improved. Further, the expression levels of chondrocyte phenotype-related genes were up-regulated, whilst that of dedifferentiated genes was down-regulated. The signal pathway proteins (Wnt3a and Wnt5a) were also participated in regulation of chondrogenesis. In vivo, compared with perichondrium, the diced cartilage wrapped with the SIS and U-SIS attained higher survival rate, less calcification and absorption in both short and long terms. Particularly, USCs promoted chondrogenesis and modulated local immune responses via paracrine pathways. In conclusion, SIS have the potential to be a new choice of membrane material for diced cartilage graft. U-SIS can enhance survival and regeneration of diced cartilage as a bioactive membrane material.

Clinical outcomes of a novel porcine small intestinal submucosa patch for full-thickness hand skin defects: a retrospective investigation

OBJECTIVE

To investigate the clinical outcomes of a novel soft tissue repair patch (porcine small intestinal submucosa patch, SIS patch) in the treatment of full-thickness hand skin defects.

METHODS

From January 2017 to July 2019, 80 patients with hand soft tissue defects, who met the inclusion criteria, were retrospectively reviewed and divided into two groups. After debridement, patients in group A were treated with the novel SIS patch to cover the wound, and patients in group B were treated with autologous skin graft. The dimensions of skin defect area and healing outcome were evaluated and recorded. Scar assessment was carried out using Scar Cosmesis Assessment and Rating Scale (SCAR scale) at the last follow-up postoperation, and the recovery of wound sensation was assessed at the same time using British Medical Research Council (BMRC) grading of sensorimotor recovery. All the data were collected and statistically analyzed.

RESULTS

A total of 80 patients were enrolled in the study with 40 patients in each group. Four patients in group A and 5 patients in group B were excluded due to wound infection and lost to follow-up. There were 36 patients in group A and 35 patients in group B finally got follow-up postoperation with mean interval of 12.75 ± 5.61 months in group A and 14.11 ± 5.42 months in group B. The dimensions of skin defect area in group A ranged from 7.5 to 87.5 cm² (mean 25.97 ± 18.66 cm²) and in group B ranged from 7.5 to 86.25 cm² (mean 33.61 ± 19.27 cm²) which have no significant difference (P > 0.05). SCAR scale results of group A and group B were 10.98 ± 0.33 and 9.49 ± 0.35, respectively, and the difference was statistically significant (P < 0.05). BMRC grading results showed 6 cases of S4, 11 cases of S3+, 5 cases of S3, 6 cases of S2, 6 cases of S1 and 2 cases of S0 in group A, and 8 cases of S4, 10 cases of S3+, 7 cases of S3, 4 cases of S2, 5 cases of S1, and 1 case of S0 in group B, which had no significant difference between them (P > 0.05).

CONCLUSIONS

The novel SIS patch is an applicable biological material in the treatment of hand skin defect, which could achieve a better cosmetic appearance of the newborn skin tissue.

Quality of Life Considerations in Endoscopic Endonasal Management of Anterior Cranial Base Tumors

Considering quality of life (QOL) is critical when discussing treatment options for patients undergoing endoscopic endonasal skull base surgery (EESBS) for cancers at the base of the skull. Several questionnaires have been developed and validated in the last 20 years to explore QOL in this patient population, including the Anterior Skull Base Questionnaire, Skull Base Inventory, EESBS Questionnaire, and the Sino-Nasal Outcome Test for Neurosurgery. The Sino-Nasal Outcomes Test-22 and Anterior Skull Base Nasal Inventory-12 are other tools that have been used to measure sinonasal QOL in anterior cranial base surgery. In addition to pathology-related perturbations in QOL endoscopic surgical options (transsellar approaches, anterior cranial base surgery, and various reconstructive techniques) all have unique morbidities and QOL implications that should be considered. Finally, we look ahead to new and emerging techniques and tools aimed to help preserve and improve QOL for patients with anterior cranial base malignancies.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Optimizing Quality of Life and Minimizing Morbidity through Nasal Preservation in Endoscopic Skull Base Surgery: A Contemporary Review

Introduction  Endoscopic endonasal approaches (EEAs) are increasingly utilized for intracranial pathology. As opposed to sinonasal tumors, the nasal cavity is being used as a corridor to access these intracranial tumors but is not the site of primary surgical intent. Accordingly, there has been recent interest in preserving intranasal structures not directly involved by tumor and improving postoperative sinonasal quality of life (QOL). Objectives  The aim of the study is to highlight recent advances in EEA techniques focused on improving sinonasal QOL including turbinate preservation, reducing the morbidity of reconstructive techniques, and the development of alternative minimally invasive EEA corridors. Methods  The method of the study involves contemporary literature review and summary of implications for clinical practice. Results  Nasoseptal flap (NSF) harvest is associated with significant morbidity including septal perforation, prolonged nasal crusting, and external nasal deformities. Various grafting and local rotational flaps have demonstrated the ability to significantly limit donor site morbidity. Free mucosal grafts have re-emerged as a reliable reconstructive option for sellar defects with an excellent sinonasal morbidity profile. Middle turbinate preservation is achievable in most EEA cases and has not been shown to cause postoperative obstructive sinusitis. Recently developed minimally invasive EEA techniques such as the superior ethmoidal approach have been described to better preserve intranasal structures while allowing intracranial access to resect skull base tumors and have shown promising sinonasal QOL results. Conclusion  This contemporary review discusses balancing effective skull base reconstructive techniques with associated morbidity, the role of turbinate preservation in EEA, and the development of unique EEA techniques that allow for increased nasal structure preservation.

The Posterior Septal Nasal Floor Mucosal Flap for Cranial Base Reconstruction

OBJECTIVE

While pedicled intranasal flaps, such as the nasoseptal flap (NSF), successfully reduce postoperative CSF leaks following endoscopic endonasal approaches (EEA) to the skull base, morbidity remains prevalent. This study describes the first cadaveric description and radiographic analysis of the posterior septal nasal floor mucosal flap (PSNF) designed to reduce pedicled nasal flap morbidity. A case series is also detailed.

STUDY DESIGN

Cadaveric dissection, radiographic analysis, and case series.

METHODS

Seven cadaver specimens underwent harvest of the PSNF. PSNF flap dimensions were measured on the thirty deidentified sinus computed tomography (CT) scans. A retrospective case series was performed on the first set of patients who received the PSNF for reconstruction of a sellar base defect. Information concerning complications, symptoms, and the appearance of the flap was recorded from records of the patient's postoperative inpatient stay, 1-week postop visit, and 1-month postop visit.

RESULTS

Cadaver dissection of the PSNF flap demonstrated good arc rotation along its pedicle with ability to cover both sellar and planum defects. Cadaveric flap measurements and CT-derived measurements estimated a mean surface area of 16.7 and 18.3 cm² , respectively. 15 patients underwent reconstruction of a sellar or planum defect using the PSNF technique. Only one CSF leak was encountered postoperatively. Minimal crusting of the flap and donor site was seen 1 month postoperatively.

CONCLUSION

The PSNF flap provides a sizeable pedicled region for reconstruction comparable to other pedicled nasal flaps. Our case series demonstrated good postoperative outcomes without reduced donor site morbidity.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Comparison of Small Intestinal Submucosal Graft and Autologous Tissue in Prevention of CSF leak after Posterior Fossa Craniotomy

Objective  To compare the use of porcine small intestinal submucosal grafts (SISG) and standard autologous material (fascia) in prevention of cerebrospinal fluid (CSF) leak and pseudomeningocele formation after translabyrinthine resection. Setting  Set at the tertiary skull base center. Methods  This is a retrospective chart review. After Institutional Review Board approval, we performed a retrospective cohort study evaluating CSF leak in patients who underwent resection of lateral skull base defects with multilayered reconstruction using either fascia autograft or porcine SISGs. Demographics were summarized with descriptive statistics. Logistic regression was used to compare autograft and xenograft cohorts in terms of CSF complications. Results  Seventy-seven patients underwent lateral skull base resection, followed by reconstruction of the posterior cranial fossa. Of these patients, 21 (27.3%) underwent multilayer repair using SISG xenograft. There were no significant differences in leak-associated complications between autograft and xenograft cohorts. Ventriculoperitoneal shunt was necessary in one (1.8%) autograft and one (4.8) xenograft cases ( p  = 0.49). Operative repair to revise surgical defect was necessary in three (5.4%) autograft cases and none in xenograft cases. Conclusion  The use of SISG as a component of complex skull base reconstruction after translabyrinthine tumor resection may help reduce CSF leak rates and need for further intervention.

Porcine small intestine graft for reconstruction of oral defects

OBJECTIVE

To evaluate the feasibility and outcomes of porcine submucosal allograft (Biodesign Sinonasal Repair Graft [Cook Medical, Bloomington, IN]) in oral cavity and oropharynx reconstruction after ablative surgery.

METHODS

We conducted a prospective and retrospective review of patients who underwent Biodesign Sinonasal Repair Graft reconstruction for oral and oropharyngeal surgical defects at a single institution between 2018 and 2020. A total of 11 patients were included in the study. Data points included their perioperative medical and demographic data, immediate postoperative course, and follow-up visits at 10 days and at 2 months. The clinicopathologic characteristics of their disease, postoperative esthetic, and functional outcomes were recorded and analyzed.

RESULTS

Eleven procedures have been performed, and all patients received Biodesign reconstruction either immediately after ablation or after they failed a previous reconstruction. None of the patients had bone exposure. The subsites included oral tongue (n = 6), floor of the mouth (n = 3), buccal mucosa (n = 1), and soft palate (n = 1). In all cases, the operations and the postoperative course were uneventful. The mean defect size was 22 cm2. The median start of oral intake was at 2 days postoperatively. The Biodesign graft healed well in all patients with no total graft loss. There was one complication that required revision surgery due to obstruction of Wharton's duct by the Biodesign material.

CONCLUSIONS

Biodesign can be a viable option for small and medium-sized oral and oropharyngeal defects in patients who are medically unfit or do not want to undergo a free flap surgery.

LEVEL OF EVIDENCE

4.

Correcting CFTR: New Gene Editing Strategies for Rescuing CFTR Function Ex Vivo

Gene correction presents one of few options for a cure for all patients with cystic fibrosis. This commentary discusses new applications of CRISPR-based gene editing technology with increased efficiency and specificity to correct the cystic fibrosis transmembrane regulator (CFTR) function in patient-specific primary epithelial cells.

Preoperative radiographic and clinical factors associated with the visualization of intraoperative cerebrospinal fluid during endoscopic transsphenoidal resection of pituitary adenomas

Background:

Intraoperative visualization of cerebrospinal fluid (CSF) during endoscopic endonasal resection of skull base tumors is the most common factor contributing to the development of postoperative CSF leaks. No previous studies have solely evaluated preoperative factors contributing to intraoperative CSF visualization. The purpose of this study was to identify preoperative factors predictive of intraoperative CSF visualization.

Methods:

Retrospective review of patients who underwent transsphenoidal resection of pituitary adenomas was conducted. Clinical and radiographic variables were compared for those who had CSF visualized to those who did not. Nominal logistic regression models were built to determine predictive variables.

Results:

Two hundred and sixty patients were included in the study. All significant demographic and radiographic variables on univariate analysis were included in multivariate analysis. Two multivariate models were built, as tumor height and supraclinoid extension were collinear. The first model, which considered tumor height, found that extension into the third ventricle carried a 4.60-fold greater risk of CSF visualization (P = 0.005). Increasing tumor height showed a stepwise, linear increase in risk; tumors >3 cm carried a 19.02-fold greater risk of CSF visualization (P = 0.003). The second model, which considered supraclinoid tumor extension, demonstrated that extension into the third ventricle carried a 4.38-fold increase in risk for CSF visualization (P = 0.010). Supraclinoid extension showed a stepwise, linear increase in intraoperative CSF risk; tumors with >2 cm of extension carried a 9.26-fold increase in risk (P = 0.017).

Conclusion:

Our findings demonstrate that tumor height, extension into the third ventricle, and extension above the clinoids are predictive of intraoperative CSF visualization.

High-Efficiency, Selection-free Gene Repair in Airway Stem Cells from Cystic Fibrosis Patients Rescues CFTR Function in Differentiated Epithelia

Cystic fibrosis (CF) is a monogenic disorder caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Mortality in CF patients is mostly due to respiratory sequelae. Challenges with gene delivery have limited attempts to treat CF using in vivo gene therapy, and low correction levels have hindered ex vivo gene therapy efforts. We have used Cas9 and adeno-associated virus 6 to correct the ΔF508 mutation in readily accessible upper-airway basal stem cells (UABCs) obtained from CF patients. On average, we achieved 30%-50% allelic correction in UABCs and bronchial epithelial cells (HBECs) from 10 CF patients and observed 20%-50% CFTR function relative to non-CF controls in differentiated epithelia. Furthermore, we successfully embedded the corrected UABCs on an FDA-approved porcine small intestinal submucosal membrane (pSIS), and they retained differentiation capacity. This study supports further development of genetically corrected autologous airway stem cell transplant as a treatment for CF.

Prospective characterization of postoperative nasal deformities in patients undergoing endoscopic endonasal skull-base surgery

BACKGROUND

Surgeons have become increasingly aware of the impact of endoscopic endonasal surgery (EES) of the skull base on sinonasal-related quality of life. Prior retrospective investigation described a correlation between nasoseptal flap (NSF) reconstruction in EES with postoperative nasal deformities, such as nasal dorsum collapse. The primary objective of this study was to prospectively evaluate the incidence of, and contributing factors to, postoperative changes in nasal structure following EES. Secondary goals included assessing subjective changes in nasal appearance as well as objective nasal analysis.

METHODS

Clinical demographics and detailed perioperative information was prospectively collected for patients undergoing transsellar/suprasellar EES for skull-base tumors. Preoperatively, 1-month and 6-month photographs were completed for objective photographic nasal analysis and blinded assessment by surgeons. Subjective patient feedback was also solicited.

RESULTS

Overall, 14.7% (5/34) of patients subjectively reported postoperative nasal deformities, whereas both blinded-surgeon and objective nasal measurements identified deformities in 12.9% (4/31) of patients. Patients with postoperative deformities were more likely to have skull-base reconstruction with an NSF (p = 0.01) and trended toward an increased incidence in patients with nonpituitary neoplasms (p = 0.07). There were no other associations between clinical or operative characteristics and external deformities. No patients planned to undergo corrective repair.

CONCLUSION

External nasal deformities following EES are more frequent than previously acknowledged. Postoperative deformities appear to be associated with NSF reconstruction and may be associated with surgery for nonpituitary neoplasms. Patients should be counseled on this potential outcome, and future studies should investigate how to minimize postoperative sequela.

Lateral nasal wall extension of the nasoseptal flap for skull-base and medial orbital wall defects

BACKGROUND

Sinonasal and skull-base tumors that previously required open resection can often be completely resected via an endonasal approach. The nasoseptal flap (NSF) is the workhorse vascularized tissue flap for the endoscopic reconstruction of large skull-base defects from tumor resections. The objective of the current article is to describe a novel modification of the NSF for simultaneous reconstruction of skull-base and medial orbital wall defects.

METHODS

An extension of the standard NSF to include mucosa of the lateral nasal wall was developed for closure of simultaneous skull-base and medial orbital wall defects. Outcomes including successful cerebrospinal fluid (CSF) leak closure, orbital edema, and postoperative cosmesis are reported. Eyelid edema was characterized according to the Surgeon Periorbital Rating of Edema and Ecchymosis (SPREE) scale.

RESULTS

Three patients underwent reconstruction using the modified NSF (average age 75 years). The average defect size of the skull base was 3.6 ± 0.1 cm by 2.3 ± 0.2 cm. The average defect size of the medial orbit was 2.7 ± 0.1 cm by 2.6 ± 0.1 cm. All defects were successfully covered intraoperatively using the lateral nasal wall extension of the NSF. Two patients developed mild eyelid edema, whereas 1 individual had no noticeable swelling (SPREE classification 2, 2, and 1). All patients were successfully sealed at last clinical follow up (average 28 weeks).

CONCLUSION

The modification of the NSF described here provides excellent coverage for reconstruction of large anterior skull-base defects and simultaneous medial orbital wall defects.

Predictors of Nasoseptal Flap Use After Endoscopic Transsphenoidal Pituitary Mass Resection

OBJECTIVE

The pedicled nasoseptal flap (NSF) is the widely accepted reconstructive technique of choice for repair of larger skull base defects after endoscopic endonasal approaches. There is a dearth of literature examining the decision-making process regarding flap harvest. The objective of this study is to evaluate preoperative characteristics that predict the use of NSF reconstruction after endoscopic transsphenoidal resection of pituitary tumors.

METHODS

In this retrospective case control study, demographic, clinical, imaging, and procedural details were gathered on all patients undergoing endoscopic transsphenoidal pituitary adenoma resection at a single academic center since January 2009. Characteristics were compared for patients receiving an NSF and those not undergoing NSF repair. A multivariate model that best predicted the use of an NSF was built and a risk score was developed.

RESULTS

Two hundred thirty-eight patients were included, and 39 underwent NSF placement. Tumor size and anatomic characteristics were the predominant factors that significantly differed between cases and controls. Patients with transsellar tumor extension had 6.3 higher odds of requiring NSF, each millimeter increase in tumor height on coronal T1 magnetic resonance imaging increased the odds of NSF use by 1.2. The flap risk score (FRS) is calculated by adding tumor height (mm) to 6 if there is transsellar extension. At an FRS of >35, the FRS is 87% specific and 85% sensitive for flap placement.

CONCLUSIONS

Preoperative imaging characteristics can predict NSF use. The FRS can be applied by surgical teams and referring physicians to determine which patients are more likely to undergo NSF repair.