Innovative Surgical Techniques Research Articles

Recurrent Paravaginal Abscess: An Unusual Presentation of a Distal Ectopic Ureteral Remnant after Prior Nephrectomy

Study Objective Describe a patient with OHVIRA syndrome and demonstrate the surgical technique used to treat her paravaginal abscess and remnant ectopic ureter. Design Video case-presentation. Setting Academic hospital. Patients or Participants Single patient. Interventions Surgery. Measurements and Main Results We describe a patient who initially presented at the onset of menarche with cyclic abdominopelvic pain. She was diagnosed with uterine didelphys with obstructed right hemivagina. She underwent a vaginoplasty, which was followed by postoperative urinary incontinence. Further work-up indicated a dysplastic right kidney with ectopic ureter to the right vaginal sidewall, correlating with diagnosis of OHVIRA syndrome. She then represented at 21 years old with chronic vaginal drainage. She underwent an extensive evaluation including imaging as well diagnostic procedures, including: cystovaginoscopy, hysteroscopy and laparoscopy. She was tested for sexually transmitted diseases, put on multiple courses of antibiotics, and had two drains placed with recurrence of drainage. When she finally presented to our facility, there was concern for abscess secondary to remnant distal ectopic ureter into the vagina. She underwent an office examination and vaginoscopy, confirming drainage from a right vaginal ostium. She was counseled and ultimately underwent a robotic assisted laparoscopic excision of paravaginal abscess and remnant of distal right ectopic ureter. She did well postoperatively. Interval CT scan on post-operative day 15 demonstrated fluid collection, which was drained by interventional radiology. The fluid collection resolved, drain removed and she has had no further recurrence of drainage. Conclusion This is an unusual presentation of a recurrent paravaginal abscess in the setting of prior partial right ectopic ureterectomy. We describe the innovative and successful surgical technique used to identify and excise the paravaginal abscess and distal ectopic ureter. Highlighting this patient's unique anatomy and the importance of complete resection of an ectopic ureter to the vagina at the time of nephrectomy due to potential risk of ascending chronic infection and abscess formation. Describe a patient with OHVIRA syndrome and demonstrate the surgical technique used to treat her paravaginal abscess and remnant ectopic ureter. Video case-presentation. Academic hospital. Single patient. Surgery. We describe a patient who initially presented at the onset of menarche with cyclic abdominopelvic pain. She was diagnosed with uterine didelphys with obstructed right hemivagina. She underwent a vaginoplasty, which was followed by postoperative urinary incontinence. Further work-up indicated a dysplastic right kidney with ectopic ureter to the right vaginal sidewall, correlating with diagnosis of OHVIRA syndrome. She then represented at 21 years old with chronic vaginal drainage. She underwent an extensive evaluation including imaging as well diagnostic procedures, including: cystovaginoscopy, hysteroscopy and laparoscopy. She was tested for sexually transmitted diseases, put on multiple courses of antibiotics, and had two drains placed with recurrence of drainage. When she finally presented to our facility, there was concern for abscess secondary to remnant distal ectopic ureter into the vagina. She underwent an office examination and vaginoscopy, confirming drainage from a right vaginal ostium. She was counseled and ultimately underwent a robotic assisted laparoscopic excision of paravaginal abscess and remnant of distal right ectopic ureter. She did well postoperatively. Interval CT scan on post-operative day 15 demonstrated fluid collection, which was drained by interventional radiology. The fluid collection resolved, drain removed and she has had no further recurrence of drainage. This is an unusual presentation of a recurrent paravaginal abscess in the setting of prior partial right ectopic ureterectomy. We describe the innovative and successful surgical technique used to identify and excise the paravaginal abscess and distal ectopic ureter. Highlighting this patient's unique anatomy and the importance of complete resection of an ectopic ureter to the vagina at the time of nephrectomy due to potential risk of ascending chronic infection and abscess formation.

1045 Summarising the Reporting of Regulatory Procedures in Robotic Cholecystectomy: A Systematic Review and Narrative Synthesis

Abstract Introduction Robotic cholecystectomy (RC) represents the most recent innovation in the management of gallstones. Whilst RC is becoming increasingly widespread, the evidence base surrounding its introduction has not been characterised. When evaluating innovative surgical techniques, adherence to regulatory and governance procedures is essential in maintaining patient safety. This study aims to appraise the reporting of studies of RC, focussing on regulatory procedures. Method Systematic searches identified all published studies reporting RC. Data collection was based on the IDEAL (Idea, Development, Exploration, Assessment, Long-term follow-up) framework, and included general study characteristics, governance approvals, trial registration, study funding, conflicts of interests, and information communicated to patients. Results Systematic searches identified 1425 abstracts. Of the 90 full-text papers included, only three were randomised controlled trials. The majority (71%) were single-centre studies. Conflicts of interest were common, with 11 (12%) studies funded by the robot manufacturer, and 23 (26%) reporting conflicts related to authors. Ethical approval was confirmed in 51 (57%) studies; four reported prior registration with a register. Only forty-two studies (47%) documented obtaining patient consent for study participation. Only four documented discussions regarding the innovative nature of RC. In ten, modifications to the robot or technique were described, but it was not apparent if patients were informed of these. Conclusions This comprehensive review highlights multiple deficiencies in the reporting of regulatory procedures in the evaluation of RC. Improved reporting is required in studies of RC to ensure transparency, interpretability, and the safe, evidence-based adoption of new technologies into clinical practice.

Preoperative Ozaki technique measures on tridimensional engineered root

BackgroundThe aortic valve neocuspidalization (AVNeo) is an innovative surgical technique aiming at the reconstruction of the aortic valve using autologous pericardium. One of the main criticisms to AVNeo is the longer duration of the aortic clamping time (ACT) as compared to standard aortic valve replacement due to the sizing of the valve neocusps. MethodsWe retrospectively enrolled 30 consecutives patients underwent AVNeo. For each patient we developed a 3D aortic root model (ARM) based on CT-scan datasets. We retrospectively compared the leaflets measurements performed during surgery with those obtained on the corresponding ARMs. ResultsIn 100% of cases no difference between the in vitro and in vivo measurements exceeded the acceptable error limit of 2 ​mm. The correlation of each single in vitro versus in vivo measurements demonstrates a strong coincidence between the two different methods of sizing (r ​> ​0,9, p ​< ​.0001). By analyzing the data considering the annulus perimeter and not the single cusp size, the perfect coincidence was to be found in 89.9% with a slight acceptable discrepancy (2 ​mm on total) in the remaining 10.1%. Conclusions3D-ARMs, printed from CT-scan, represent a reproducible process to obtain overlapping cusp sizes compared to those measured in-vivo, possibly reducing the ACT.

Use of micro-grafts in a chronic infected open wound after limb amputation in a cat

In human medicine, skin grafting is an innovative surgical technique widely used in reconstructive surgery to repair skin loss. This case evaluated the effectiveness of a treatment with dermal micro-grafting obtained through the Rigenera&lt;sup&gt;®&lt;/sup&gt; technology in a chronic open wound resulting from a suture dehiscence of a limb amputation in a cat. Significant differences were observed between the aesthetic aspects of the injury using traditional treatments (cleaning and curettage) and the regenerative technology. The results showed that the healing periods were significantly reduced after the Rigenera&lt;sup&gt;®&lt;/sup&gt; treatment and that, moreover, a perfect skin status and a complete reduction in the wound area (100%) were achieved in one month. Given these results, Rigenera&lt;sup&gt;®&lt;/sup&gt; has proven to be a simple yet highly effective method in the treatment of inactivated chronic wounds.

Biological Characterization of Human Autologous Pericardium Treated with the Ozaki Procedure for Aortic Valve Reconstruction.

Background: The Ozaki procedure is an innovative surgical technique aiming at reconstructing aortic valves with human autologous pericardium. Even if this procedure is widely used, a comprehensive biological characterization of the glutaraldehyde (GA)-fixed pericardial tissue is still missing. Methods: Morphological analysis was performed to assess the general organization of pericardium subjected to the Ozaki procedure (post-Ozaki) in comparison to native tissue (pre-Ozaki). The effect of GA treatment on cell viability and nuclear morphology was then investigated in whole biopsies and a cytotoxicity assay was executed to assess the biocompatibility of pericardium. Finally, human umbilical vein endothelial cells were seeded on post-Ozaki samples to evaluate the influence of GA in modulating the endothelialization ability in vitro and the production of pro-inflammatory mediators. Results: The Ozaki procedure alters the arrangement of collagen and elastic fibers in the extracellular matrix and results in a significant reduction in cell viability compared to native tissue. GA treatment, however, is not cytotoxic to murine fibroblasts as compared to a commercially available bovine pericardium membrane. In addition, in in vitro experiments of endothelial cell adhesion, no difference in the inflammatory mediators with respect to the commercial patch was found. Conclusions: The Ozaki procedure, despite alteration of ECM organization and cell devitalization, allows for the establishment of a noncytotoxic environment in which endothelial cell repopulation occurs.

Regional Anesthetic Approaches for Postoperative Analgesia Following Vertebral Body Tethering: A Case Series.

Vertebral body tethering (VBT) is an innovative surgical technique used to treat juvenile and adolescent idiopathic scoliosis. The optimal anesthetic technique, including the preferred management of postoperative pain, is not known. In this case series, we describe 3 patients with adolescent idiopathic scoliosis who received either continuous erector spinae plane block (ESPB) catheters or intercostal liposomal bupivacaine for postoperative pain management after bilateral VBT via minithoracotomy.

Patient-specific 3D-printed cutting guides for high oblique sagittal osteotomy-an innovative surgical technique for nerve preservation in orthognathic surgery.

Bilateral sagittal split osteotomy (BSSO) of the mandible according to Obwegeser/Dal Pont is considered to be gold standard in orthognathic surgery. Frequently reported complications of BSSO are injuries of the mandibular nerve resulting in paresthesia/anesthesia as well as inadequate mandibular bone fracturing (‘bad split’). High oblique sagittal osteotomy (HOSO) was introduced to overcome these complications. We present an innovative HOSO modification using patient-specific 3D-printed cutting guides positioned on the outside of the ascending mandibular ramus and fixed in the incisura semilunaris, precisely marking the optimal height and angle of the osteotomy. Advantages are a decreased operation time due to the simplicity of this less invasive procedure, a potentially reduced frequency of mandibular nerve damage and bad splits as well as a lower bleeding risk.

Safe implementation of robotic-assisted minimally invasive direct coronary artery bypass: application of learning curves and cumulative sum analysis.

BackgroundLearning curves are inevitably encountered when first implementing an innovative and complex surgical technique. Nevertheless, a cluster of failures or complications should be detected early, but not deter learning, to ensure safe implementation. Here, we aimed to examine the presence and impact of learning curves on outcome after robotic-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB).MethodsA retrospective analysis of the first 300 RA-MIDCAB surgeries between July 2015 and December 2020 was performed. Learning curves were obtained via logarithmic regression for surgical time. Cumulative sum (CUSUM) analysis was performed for (I) major complications including MI, stroke, repeat revascularization, and mortality, and (II) other complications, including prolonged ventilation, pneumonia, pleura puncture, lung herniation, pericarditis, pleuritis, arrhythmia, wound complications, and delirium. Expected and unacceptable rates were set at 12% and 20%, respectively, for major complications, and at 40% and 60% for other complications, based on historical data in conventional coronary artery bypass grafting (CABG).ResultsDemographic characteristics did not differ between terciles, except for more smokers in the first tercile, and less hypercholesterolemia and more complex procedures in the third tercile. The mean surgical time for all operations was 258±81 minutes, ranging from 127 to 821 minutes. A learning curve was only observed in the first tercile. Subgroup analysis revealed that this learning curve was only observed for procedures consisting of single internal mammary artery (SIMA) with 1 or 2 distal anastomoses but not with bilateral internal mammary arteries (BIMA) or more than 2 distal anastomoses. CUSUM analysis showed that the cumulative rate of major and other complications never crossed the lines for unacceptable rates. Rather, the lower 95% confidence boundary was crossed after 50 cases, indicating improvement in safety.ConclusionsThese results suggest that integration of RA-MIDCAB in the surgical landscape can be safely achieved and complication rates can quickly be reduced below those expected in traditional CABG. Collective experience plays a key role in overcoming the learning curve when more complex procedures and cases are introduced.

Trends in Surgical Glaucoma Treatment in Germany Between 2006 and 2018.

Background/AimsSurgical procedures in ophthalmology underlie variations over different time periods and are strongly dependent on the technical process and the invention of innovative surgical techniques. Especially, in glaucoma surgery a lot of surgical devices and techniques have been introduced during the last years. Until now, the use of these newer techniques has not been shown on a robust data basis. We herein present the numbers of different types of glaucoma surgeries performed at German hospitals between 2006 and 2018.Methods and DesignThe quality reports of hospitals in Germany from 2006 to 2018 were analyzed concerning all procedural codes for glaucoma surgery and intervention. Especially, the change in usage of “classical” and “modern” surgical techniques (MIGS: “minimally invasive glaucoma surgery”) or devices was compared.ResultsThe number of glaucoma procedures performed increased by 75% from 27,811 in 2006 to 48,794 in 2018. Absolute numbers of trabeculectomies, goniotomies, ab externo trabeculotomies and to a certain level cyclodestructive procedures decreased during the examined years while use of MIGS has increased in absolute and relative numbers since 2012. From 2015 a strong increase in the usage of XEN implants could be seen. Drainage implants (such as Baerveldt/Ahmed) showed stable absolute numbers over the time period covered. Absolute numbers of laser trabeculoplasty peaked in 2014 and decreased afterwards. Iridotomies and iridectomies increased by 120%/248% over the whole period.ConclusionOur data show a trend towards the modern surgical options and especially MIGS during the recent years. Classical procedures showed a decrease in total numbers emphasized from 2013. These numbers confirm the assumption that modern glaucoma surgery is becoming more and more popular and established in German hospitals.

Hemodynamics in the Aorta and Pulmonary Arteries of Congenital Heart Disease Patients: A Mini Review

Congenital heart disease, which affects more than one million newborns globally each year, contributes to an increased risk of cardiovascular disease and ultimately reduced life expectancy. Computational fluid dynamics (CFD) enables detailed, non-invasive characterization of complex physiological pressure and flow fields, thus improving our understanding of congenital heart disease hemodynamics. In recent years, this has driven clinical decision-making, surgical planning, and the evaluation of innovative surgical techniques. In this mini review, CFD methods applied to the study of congenital abnormalities, with a focus on the aorta and pulmonary bifurcation, are discussed. The clinical relevance and future directions of CFD modelling are also reviewed.

Tricuspid Valve Tethering Is Associated with Residual Regurgitation after Valve Repair in Hypoplastic Left Heart Syndrome: A Three-Dimensional Echocardiographic Study

Tricuspid valve regurgitation (TR) is a risk factor for morbidity and mortality in children with hypoplastic left heart syndrome (HLHS). Surgical tricuspid valve (TV) repair is common, but durable repair remains challenging. The aim of this study was to examine mechanisms of TR requiring surgery, features associated with unsuccessful repair, and TV changes after surgical repair. Thirty-six patients with HLHS requiring TV repair (TVR) and 36 matched control subjects with HLHS were assessed using two-dimensional and three-dimensional echocardiography. Using three-dimensional echocardiography, TV coordinates from the annulus, leaflet, and ventricle were used to measure annular, leaflet, prolapse, and tethering values and anterior papillary muscle angle. TR grade and ventricular size, function, and shape were assessed using two-dimensional echocardiography. Patients requiring TVR had greater total leaflet prolapse, larger TV annular and leaflet areas, and flatter annuli, with no difference in tethering, coaptation index, or anterior papillary muscle angle. In patients with HLHS, successful TVR at follow-up (58%) was associated with preoperative total leaflet prolapse (especially posterior). Unsuccessful repair was associated with preoperative tethering of the septal leaflet. TVR in patients with HLHS caused a reduction of total annular and leaflet size and reduced prolapse and tethering of the posterior leaflet but did not affect anterior leaflet prolapse or septal leaflet tethering. Features associated with TVR include a flattened and dilated TV annulus with leaflet prolapse. The additional presence of a tethered septal leaflet before TVR is associated with significant postoperative TR. Current surgical techniques, predominantly posterior annuloplasty and commissuroplasty, adequately address annular size and posterior leaflet pathology, but not septal leaflet tethering. Individualized and innovative surgical techniques are vital to improve surgical repair success.

Single-Port Three-Dimensional (3D) Videoscope-Assisted Endoscopic Nipple-Sparing Mastectomy in the Management of Breast Cancer: Technique, Clinical Outcomes, Medical Cost, Learning Curve, and Patient-Reported Aesthetic Results from 80 Preliminary Procedures

The preliminary results of an innovative surgical technique, which incorporated single-port three-dimensional (3D) videoscope and instruments for endoscopic nipple-sparing mastectomy (E-NSM), were reported. The medical records of patients who underwent single-port 3D E-NSM for breast cancer from August 2018 to September 2020 were analyzed, and the preliminary outcome of this procedure as well as the patient-reported aesthetic results are described in this article. The study enrolled 70 patients who received 80 procedures of single-port 3D E-NSM. The mean operation time was 158 ± 36 min, and the mean blood loss was 41 ± 26 ml. Three procedures (3.8 %) associated with delayed axillary wound-healing, eight cases of transient nipple ischemia (10 %), three cases of partial nipple ischemia/necrosis (3.7 %), and one case of total nipple-areolar complex (NAC) necrosis (1.3 %) were observed. No patient had margin involvement. Satisfaction rates of approximately 90 % were observed in terms of postoperative scar appearance, location, and length. Most of the patients (87.8 %) reported that they would choose the same operation again if given the chance to do so. The overall cost of a single-port 3D E-NSM was 7522 ± 470 U.S. dollars. According to cumulative sum (CUSUM) plot analysis, about 14 cases were needed for surgeons to familiarize themselves with single-port 3D E-NSM and immediate gel implant reconstruction and to decrease their operation time significantly in the initial learning phase. Single-port 3D E-NSM, a safe, efficient, lower-cost procedure, is associated with a good aesthetic result. It is a promising new technique for breast cancer patients indicated for mastectomy, but long-term oncologic safety follow-up evaluation still is needed.

Uncommon indications for associating liver partition and portal vein ligation for staged hepatectomy: a systematic review.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) represents an innovative surgical technique used for the treatment of large hepatic lesions at high risk for post-resection liver failure due to a small future liver remnant. The most significant amount of literature concerns the use of ALPPS for the treatment of hepatocellular carcinoma (HCC), cholangiocarcinoma (CCC), and colorectal liver metastases (CRLM). On the opposite, few is known about the role of ALPPS for the treatment of uncommon liver pathologies. The objective of the present study was to evaluate the current literature on this topic. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible articles published up to February 2020 were included using the MEDLINE, Scopus, and Cochrane databases. Among the 486 articles screened, 45 papers met the inclusion criteria, with 136 described cases of ALPPS for rare indications. These 136 cases were reported in 18 different countries. Only in two countries, namely Germany and Brazil, more than ten cases were observed. As for the ALPPS indications, we reported 41 (30.1%) cases of neuroendocrine tumor (NET) metastases, followed by 27 (19.9%) cases of gallbladder cancer (GBC), nine (6.6%) pediatric cases, six (4.4%) gastrointestinal stromal tumors, six (4.4%) adult cases of benign primary liver disease, four (2.9%) adult cases of malignant primary liver disease, and 43 (31.6%) adult cases of malignant secondary liver disease. According to the International ALPPS Registry data, less than 10% of the ALPPS procedures have been performed for the treatment of uncommon liver pathologies. NET and GBC are the unique pathologies with acceptable numerosity. ALPPS for NET appears to be a safe procedure, with satisfactory long-term results. On the opposite, the results observed for the treatment of GBC are poor. However, these data should be considered with caution. The rationale for treating benign pathologies with ALPPS appears to be weak. No definitive response should be given for all the other pathologies. Multicenter studies are needed with the intent to clarify the potentially beneficial effect of ALPPS for their treatment.

Control Strategies and Performance Assessment of Upper-Limb TMR Prostheses: A Review.

The evolution of technological and surgical techniques has made it possible to obtain an even more intuitive control of multiple joints using advanced prosthetic systems. Targeted Muscle Reinnervation (TMR) is considered to be an innovative and relevant surgical technique for improving the prosthetic control for people with different amputation levels of the limb. Indeed, TMR surgery makes it possible to obtain reinnervated areas that act as biological amplifiers of the motor control. On the technological side, a great deal of research has been conducted in order to evaluate various types of myoelectric prosthetic control strategies, whether direct control or pattern recognition-based control. In the literature, different control performance metrics, which have been evaluated on TMR subjects, have been introduced, but no accepted reference standard defines the better strategy for evaluating the prosthetic control. Indeed, the presence of several evaluation tests that are based on different metrics makes it difficult the definition of standard guidelines for comprehending the potentiality of the proposed control systems. Additionally, there is a lack of evidence about the comparison of different evaluation approaches or the presence of guidelines on the most suitable test to proceed for a TMR patients case study. Thus, this review aims at identifying these limitations by examining the several studies in the literature on TMR subjects, with different amputation levels, and proposing a standard method for evaluating the control performance metrics.

Fertility and Sterility top videos from 2017 to 2019

To objectively grade all video publications in Fertility and Sterility during the years 2017-2019 and compile a list of the top 10 surgical videos. Descriptive presentation of the 10 highest-scoring video publications from Fertility and Sterility in the years 2017-2019. Not applicable. Not applicable. All 4 authors acted as independent reviewers of all video publications. A standardized scoring method was used to score all videos. Up to 5 points were awarded for each of the following categories: Scientific merit or clinical relevance of the topic; clarity of video; use of innovative surgical technique; and video editing or use of marking tools on the video to highlight important features or surgical landmarks. This allowed a maximum score of 20 for each video. The number of YouTube views and likes were used as a tiebreaker if ≥2 videos scored similarly. The interclass coefficient from a 2-way random effects model was calculated to assess for agreement between the 4 independent reviewers. A total of 40 videos were published in Fertility and Sterility during the years 2017-2019. After averaging scores from all 4 reviewers, a top 10 list was created (Table). Only 2 videos (number 6 and 7 spots) had the same average score, and the number of YouTube views and likes were used as a tiebreaker. The overall interclass coefficient for the 4 reviewers was 0.68 (95% confidence interval, 0.52-0.76). An overall substantial agreement was noted between the 4 reviewers. Ten videos reigned supreme from a list of very competitive publications that had already undergone the peer review process. The subject matter of these videos ranged from complex surgical procedures, including uterus transplantation and use of a biologic graft for neovaginoplasty, to common procedures like hysteroscopic removal of intrauterine devices during pregnancy and approaches to the stenotic cervix.

Innovative Surgical Techniques for Nasal Septal Perforations: Management and Treatment.

The aim of this study was to review and describe the main innovative surgical techniques for nasal septal perforation (NSP) repair that have been published in recent years. Several techniques for NSP repair have been developed recently. The anterior ethmoidal artery (AEA) flap is a versatile technique for middle-size perforations in different locations. The greater palatine artery (GPA) flap is an excellent option for anterior-most NSPs. The lateral nasal wall flap and the pericranial flap are the most appropriate techniques for large perforations. The advent of these techniques has changed the management and has expanded the therapeutic arsenal to treat all types of NSPs according to the size, location, and osteo-cartilaginous support. However, no technique has been accepted as the gold standard. Extensive knowledge of different techniques is important to individualize the treatment, selecting the most appropriate in each case.

Spontaneous and Engineered Large Animal Models of Neurofibromatosis Type 1.

Animal models are crucial to understanding human disease biology and developing new therapies. By far the most common animal used to investigate prevailing questions about human disease is the mouse. Mouse models are powerful tools for research as their small size, limited lifespan, and defined genetic background allow researchers to easily manipulate their genome and maintain large numbers of animals in general laboratory spaces. However, it is precisely these attributes that make them so different from humans and explains, in part, why these models do not accurately predict drug responses in human patients. This is particularly true of the neurofibromatoses (NFs), a group of genetic diseases that predispose individuals to tumors of the nervous system, the most common of which is Neurofibromatosis type 1 (NF1). Despite years of research, there are still many unanswered questions and few effective treatments for NF1. Genetically engineered mice have drastically improved our understanding of many aspects of NF1, but they do not exemplify the overall complexity of the disease and some findings do not translate well to humans due to differences in body size and physiology. Moreover, NF1 mouse models are heavily reliant on the Cre-Lox system, which does not accurately reflect the molecular mechanism of spontaneous loss of heterozygosity that accompanies human tumor development. Spontaneous and genetically engineered large animal models may provide a valuable supplement to rodent studies for NF1. Naturally occurring comparative models of disease are an attractive prospect because they occur on heterogeneous genetic backgrounds and are due to spontaneous rather than engineered mutations. The use of animals with naturally occurring disease has been effective for studying osteosarcoma, lymphoma, and diabetes. Spontaneous NF-like symptoms including neurofibromas and malignant peripheral nerve sheath tumors (MPNST) have been documented in several large animal species and share biological and clinical similarities with human NF1. These animals could provide additional insight into the complex biology of NF1 and potentially provide a platform for pre-clinical trials. Additionally, genetically engineered porcine models of NF1 have recently been developed and display a variety of clinical features similar to those seen in NF1 patients. Their large size and relatively long lifespan allow for longitudinal imaging studies and evaluation of innovative surgical techniques using human equipment. Greater genetic, anatomic, and physiologic similarities to humans enable the engineering of precise disease alleles found in human patients and make them ideal for preclinical pharmacokinetic and pharmacodynamic studies of small molecule, cellular, and gene therapies prior to clinical trials in patients. Comparative genomic studies between humans and animals with naturally occurring disease, as well as preclinical studies in large animal disease models, may help identify new targets for therapeutic intervention and expedite the translation of new therapies. In this review, we discuss new genetically engineered large animal models of NF1 and cases of spontaneous NF-like manifestations in large animals, with a special emphasis on how these comparative models could act as a crucial translational intermediary between specialized murine models and NF1 patients.

Biliary complications after liver transplantation: current perspectives and future strategies.

Liver transplantation (LT) is a life-saving therapy for patients with end-stage liver disease and with acute liver failure, and it is associated with excellent outcomes and survival rates at 1 and 5 years. The incidence of biliary complications (BCs) after LT is reported to range from 5% to 20%, most of them occurring in the first three months, although they can occur also several years after transplantation. The aim of this review is to summarize the available evidences on pathophysiology, risk factors, diagnosis and therapeutic management of BCs after LT. a literature review was performed of papers on this topic focusing on risk factors, classifications, diagnosis and treatment. Principal risk factors include surgical techniques and donor's characteristics for biliary leakage and anastomotic biliary strictures and vascular alterations for non- anastomotic biliary strictures. MRCP is the gold standard both for intra- and extrahepatic BCs, while invasive cholangiography should be restricted for therapeutic uses or when MRCP is equivocal. About treatment, endoscopic techniques are the first line of treatment with success rates of 70-100%. The combined success rate of ERCP and PTBD overcome 90% of cases. Biliary leaks often resolve spontaneously, or with the positioning of a stent in ERCP for major bile leaks. BCs influence morbidity and mortality after LT, therefore further evidences are needed to identify novel possible risk factors, to understand if an immunological status that could lead to their development exists and to compare the effectiveness of innovative surgical and machine perfusion techniques.

The role of endovascular and endobiliary methods in the treatment of post-liver transplant complications

Liver transplantation is the treatment of choice for patients with end-stage liver disease or acute liver failure. However, vascular complications, such as hepatic artery stenosis and/or thrombosis, graft portal vein stenosis and biliodigestive strictures following liver transplantation are still common despite improvements and innovations in surgical techniques. These complications can lead to graft damage or even death, and they are caused by many factors. Although minimally invasive interventional radiology is an optional treatment for such post-liver transplant complications, there is little research on this method of treatment.

Pediatric Airway Surgery: Advances in Evaluation and Endoscopic Management

Pediatric airway evaluation and surgery have evolved over time to involve less invasive techniques in order to facilitate quicker recovery and potentially less discomfort. Over the past decade, new indications, techniques, and data have emerged to support the use of these techniques routinely. In this article, we present techniques for evaluation and outcomes for endoscopic management of the pediatric larynx and review relevant recent publications relevant to pediatric endoscopic airway surgery. Laryngeal ultrasound has been shown to be an effective modality for evaluating vocal fold motion and potentially for evaluating laryngeal lesions. Innovations in surgical techniques include epiglottopexy for supraglottic obstruction, new airway balloons for dilating subglottic stenosis, and endoscopic cricoid split with or without a cartilage graft and vocal fold suture lateralization for bilateral vocal fold immobility. Less invasive techniques of diagnosis and management are viable options for pediatric airway patients and may replace or serve as adjuncts to traditional modalities.