Heterologous Material Research Articles

Cadaver Homologous Banked Fascia Lata in Skull Base Reconstruction: Preliminary Multidisciplinary Experiences.

Skull base reconstruction has been a widely debated issue. Both autologous and heterologous materials have been proposed, however the formers are usually preferred due to their optimal healing outcomes and integration. Nevertheless they are still associated with donor-site functional and aesthetic morbidity. The aim of this study is to report a preliminary experience of different sites defects skull base repair with Cadaver homologous banked fascia lata graft. Patients who underwent reconstruction of skull base defects with Cadaver homologous banked fascia lata between January 2020 until July 2021 were included in the study. Three patients were finally identified for the study. Patient 1 underwent combined craniotomic-endoscopic surgical access for extended anterior skull base neoplasm with subsequent repair with homologous cadaver fascia lata. Patient 2 underwent endoscopic transphenoidal surgery for sellar-parasellar neoplasm. After tumor debulking the surgical cavity was obliterated with homologous cadaver fascia lata. Patient 3 finally had politrauma with otic capsule-violating fracture with profused CSF leak. An endoscopic obliteration of external and middle ear was performed using homologous cadaver fascia lata with blind sac closure of external auditory canal. No graft displacement or reabsorption was observed in these patients at the last follow-up. Cadaver homologous banked fascia lata has proved safety, efficacy and ductility in reconstruction of different skull base defects. Level of Evidence: Level IV-retrospective cohort study.

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty.

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery.

Radiographic Analysis of Graft Dimensional Changes after Lateral Maxillary Sinus Augmentation with Heterologous Materials and Simultaneous Implant Placement: A Retrospective Study in 18 Patients.

Background: This investigation aimed to radiographically assess the variations of graft dimension following maxillary sinus augmentation by the lateral approach. Methods: Eighteen patients (seven males), with a mean age at surgery of 66.5 ± 9.8 (range 52–82) years, were unilaterally treated. Thirty-five dental implants were positioned in the posterior maxilla simultaneously to grafting with heterologous biomaterials. Intraoral radiographs taken at the time of surgery, after six months, and at the longest follow-up (up to nine years after implant placement) were analyzed. The following distances were measured: mesio-distal width of the graft, vertical distance from implant apex to most coronal level of the graft, distance from the mesial aspect of the (mesial) implant to the mesial graft extension; distance from the distal aspect of the (distal) implant to the distal graft extension, and graft height along the implant axis. The dimensional changes with respect to baseline, after six months and at the longest follow-up were calculated. Results: The patient-based mean follow-up was 38.3 ± 30.1 months (range 12–108 months). The mean residual bone height at the mesial and distal aspect of the implants was 3.19 ± 2.05 mm and 2.65 ± 1.60 mm, respectively (p = 0.38). The mean graft width at baseline was 27.95 ± 5.23 mm, and the mean graft width reduction was 10.2 ± 12.7% (2.98 ± 3.62 mm) and 11.3 ± 14.4% (3.36 ± 4.08 mm) at six months and at the latest follow-up. The change was significant at six months (p = 0.005), but did not show significant further variation (p = 0.11). On the mesial and distal aspect, the mean graft extension decreased by 1.56 ± 2.67 mm and 0.84 ± 2.71 mm at the latest follow-up. No significant difference between mesial and distal changes was found (p = 0.24), suggesting that the biomaterial is resorbed homogeneously on both sides. The mean graft height was 11.92 ± 2.53 mm at baseline and decreased by 9.3 ± 9.05% (1.11 ± 1.09 mm) at six months (p < 0.001). Non-significant further changes were found at the latest follow-up (p = 0.10). Conclusions: after early remodeling, heterologous bone substitutes showed a good dimensional stability in the mid-term for maxillary sinus augmentation.

A Multicentric European Clinical Study on Custom-Made Porous Hydroxyapatite Cranioplasty in a Pediatric Population.

BackgroundCranioplasty (CP) is a surgical intervention aiming to re-establish the integrity of skull defects. Autologous bone and different heterologous materials are used for this purpose, with various reported related complications, especially in children.This study aims to evaluate the rate of complication in a multicentric cohort of pediatric patients treated by porous hydroxyapatite (PHA) CP implantation and to assess the reliability of post-marketing clinical data collected by a manufacturing company.MethodsThe authors proactively collected clinical data from 20 institutions in different European countries for patients under the age of 16 treated with a PHA implant. The data were obtained by conducting an on-site interview with physicians in charge of the patients (Post-Marketing Surveillance, PMS group). The endpoints were the incidence of adverse events and related implant removal. The clinical data were compared to the company-based register including all patients under the age of 16 who received the same implant from January 1, 2004 to December 31, 2020, and the collecting complications voluntarily reported by surgeons (Database, DB group).ResultsThe two groups were similar in terms of demographic characteristics and rate of complications. In the PMS group, a total of 11 (16.9%) complications were reported in the group of 65 patients that were proactively collected. Both fractures and infections were the most common complications with 4 cases each (6.2%). In the case of both infections and fractures, revision surgery was required for only one patient (1.5%). Three (4.5%) cases of displacements were reported, and in one (1.5%) case, a surgical revision was required, for a total of 3 (4.5%) cases requiring surgical revision. The average follow-up was 26.7 months.ConclusionsDifferent from a previous study on adult age, pediatric neurosurgeons are more prone to report even to the manufacturing company complications related to skull reconstruction in children. Therefore, these data can be compared with those of other clinical studies. The PHA CP in this series of 65 patients presents a complication rate collected on-site that is similar to other heterologous materials.

Emerging Mechanisms of Endocytosis in Toxoplasma gondii.

Eukaryotes critically rely on endocytosis of autologous and heterologous material to maintain homeostasis and to proliferate. Although mechanisms of endocytosis have been extensively identified in mammalian and plant systems along with model systems including budding yeast, relatively little is known about endocytosis in protozoan parasites including those belonging to the phylum Apicomplexa. Whereas it has been long established that the apicomplexan agents of malaria (Plasmodium spp.) internalize and degrade hemoglobin from infected red blood cells to acquire amino acids for growth, that the related and pervasive parasite Toxoplasma gondii has a functional and active endocytic system was only recently discovered. Here we discuss emerging and hypothesized mechanisms of endocytosis in Toxoplasma gondii with reference to model systems and malaria parasites. Establishing a framework for potential mechanisms of endocytosis in Toxoplasma gondii will help guide future research aimed at defining the molecular basis and biological relevance of endocytosis in this tractable and versatile parasite.

Long-term follow-up of custom-made porous hydroxyapatite cranioplasty in adult patients: a multicenter European study. Can we trust self-reported complications?

Cranioplasty is a surgical intervention aiming to re-establish the integrity of skull defects. Autologous bone and different heterologous materials are used for this purpose, with various reported related complications. The aim of the study was to evaluate the complication rate in a multicentric cohort of patients underwent porous hydroxyapatite (PHA) cranioplasty implantation and to assess the validity of company post-market clinical analysis. Authors analyzed a company-based register of 6279 PHA cranioplasty implanted all over the world. In these adult patients only self-reported complications were available. We then obtained the data of adult patients treated with custom-made porous HA prostheses (CustomBone Service) in 20 institutions from different European countries through an on-site interview with the physicians in charge of the patients (N.=494). The endpoints were the incidence of adverse events and of related implant removal. The groups of patients had similar demographics characteristics. The average follow-up was 26.7 months. A significantly higher number of complications was recorded in the group of patients underwent on-site interview. Thirty-nine complications were reported (7.89%) with an explantation rate of 4.25% (21 cases) in the series, compared to the data reported from the Company (complications rate of 3.3% and explantation rate of 3.1%). The most common complications were infection (4.86%), hematomas (1.22%), fractures (1.01%), mobilization (0.4%) and scar retraction (0.4%). Our data confirm that porous HA cranioplasty is at least as effective as other heterologous materials to repair cranial defects. Another interesting finding is that self-reporting complications by surgeons does not give a precise picture of the real rate of complications of the devices. These data in future studies need to be re-confirmed with on-site interviews.

Comparison of a purely endoscopic three-layer technique versus pericranial flap for reconstruction of anterior skull base defects after sino-nasal tumor resection: assessment of postoperative frontal lobe sagging and frontal lobe falling.

The evolution of endoscopic skull base approaches has enabled surgeons to manage selected skull base tumors through a transnasal endoscope-assisted approach. On the other side, more extensive lesions may require a combined cranioendoscopic approach. In this paper, we analysed and compared the incidence of frontal lobe sagging after endoscopic multilayer (EM) reconstruction versus pericranial flap (PF) reconstruction. Subjects were selected retrospectively according to specific inclusion and exclusion criteria. The degree of frontal lobe sagging after surgery was calculated based on the most inferior position of the frontal lobe relative to the nasion-sellar line defined on preoperative and postoperative imaging. A positive value signified upward displacement, and a negative value represented frontal lobe sagging. Twenty subjects were enrolled in our study. In the EM technique group the average frontal lobe displacement was -2,34 ± 1,55 mm. The average postoperative frontal lobe sagging was -0,45 ± 8,92 mm in subjects reconstructed with the PF. The skull base defect size correlated with the degree of frontal lobe sagging in subjects reconstructed with the PF, but not in the other group and when merging the two groups. In conclusion, the EM technique and the PF reconstruction showed a good reliability for the closure of anterior skull base defects. Moreover the PF seemed to prevent frontal lobe sagging but, for larger skull base defects, it could be useful to be combined with other autologous or heterologous materials to avoid the frontal lobe falling.

Cranioplasty for bone defects after craniosynostosis surgery. Case series with literature review

IntroductionSurgical treatment of craniosynostosis in children may generate secondary cranial vault defects by incomplete ossification process. The incidence of cranial defects after craniosynostosis surgery is poorly reported in the literature with a variable incidence of 0.5% to 18.2%. To better understand the impact and management of the cranial defects after craniosynostosis surgery, we selected and reviewed al cranioplasties that met this criterion between 2002 and 2019. Patients and methodWe found 41 patients (28 M and 13 F) operated between January 2002 to January 2019 who underwent cranioplasty for cranial defects secondary to craniosynostosis surgery in the infancy. All patient were at least 5 years old (range 5 to 17 years, median 11). The indication was aesthetic in 28 patients and for headaches, learning difficulties or changes in the cerebral blood flow in 13 patients. The material used in cranioplasty was the poly-methyl-methacrylate (PMMA) in 40 patients and customized porous hydroxyapatite (CPHA) in 1 patient. ResultsThe mean follow-up period after cranioplasty was of 37 months (range 2 to 125 months, median of 27 months). In the postoperative period there were no mortality nor neurological complications. There were 3 cases (7%) of superficial local postoperative wound infection but with no evidence of long-term infection. The long-term CT scan follow-up showed no material migration, dislocation or fractures. ConclusionConsidering the characteristics of the cranial vault after craniosynostosis surgery the treatment by cranioplasty with heterologous materials appears to be feasible thus avoiding donor site morbidity. For selected cases with small defects, our experience shows that the use of PMMA may be a safe alternative for the cranial vault repair in children older than 5 years.

Surgical anatomy of the aortic valve and root-implications for valve repair.

The aortic root is an important anatomical structure positioned at the center of the heart, making it critical to the functioning of the major cardiac chambers. Deep knowledge of the anatomical "surroundings" of the aortic root is crucial for surgeon attempting to spare or repair a leaking aortic valve. In fact, root dissection is a necessary step to "skeletonize" the aortic valve, allowing the surgeon to work on the critical components of its structure, namely the aorto-ventricular junction, the virtual basal ring (VBR) and the sino-tubular junction (STJ). These three components, along with the insertion of the leaflet to the aortic wall, form the skeleton of the aortic valve that is essential in guaranteeing valve competence. A good anatomical proportion between the various component of the skeleton of the aortic valve need to be verified, or re-established in order to set the basis for an optimal aortic valve repair. Once the skeleton of the heart has been correctly addressed, the condition of the valve leaflets need to be considered. Excess of leaflet tissue is treated by leaflet plication or resection and lack of leaflet tissue is addressed by tissue extension with autologous or heterologous materials. In the present manuscript, we highlight the principal structure of the aortic root and describe in detail each anatomical component. This basic anatomical knowledge is also important for a through understanding of the normal function of the valve and root structure during the cardiac cycle. The close boundaries existing between the left ventricular cavity and the aorta are important in explaining the sophisticated function of opening and closing of the aortic valve. Similarly, the role played by the sinuses of Valsalva in regulating the blood flow exiting the ventricle underline the concept that "form follows function" and emphasizes the importance of a good anatomical reconstruction for an optimal and long-lasting valve function.

Temporal bone trauma effects on auditory anatomical structures in mastoid obliteration.

The risk of temporal bone fractures in head trauma is not negligible, as injuries also depend on the resistance and integrity of head structures. The capacity of mastoid cells to absorb part of the impact kinetic energy of the temporal bone is diminished after open cavity mastoidectomy, even if the surgical procedure is followed by mastoid obliteration. The aim of our study was to evaluate the severity of lesions in auditory anatomical structures after a lateral impact on cadaveric temporal bones in which open cavity mastoidectomy followed by mastoid obliteration was performed, compared to cadaveric temporal bones with preserved mastoids. The study was carried out on 20 cadaveric temporal bones, which were randomly assigned to two groups. In the study group, open cavity mastoidectomy followed by mastoid obliteration with heterologous materials was performed. All temporal bones were impacted laterally under the same conditions. Temporal bone fractures were evaluated by CT scan. External auditory canal fractures were six times more seen in the study group. Tympanic bone fractures were present in 80% of the samples in the study group and 10% in the control group (p = .005). Middle ear fractures were found in 70% of the samples in the study group and 10% in the control group (p = .02). Otic capsule violating fractures of the temporal bone were present only in the study group. Mastoid obliteration with heterologous materials after open cavity mastoidectomy increases the risk of fracture, with the involvement of auditory anatomical structures.

Cranioplasty with Porous Hydroxyapatite Custom-Made Bone Flap: Results from a Multicenter Study Enrolling 149 Patients Over 15 Years

Despite the mixed evidence regarding the effect of decompressive craniectomy in terms of outcome, a tremendous increase in related reports has been observed in the last years. Cranioplasty plays a key role in restoring function and anatomy of the cranial vault. Considering that cranioplasty is not exempt from risks, the identification of the safest technique becomes crucial to achieve better patients' recovery. Porous hydroxyapatite (PHA) has received growing attention for its potential in bony integration. Here we report a multicenter prospective follow-up analysis of 149 patients who underwent cranioplasty with PHA prostheses. In particular, we focus on the incidence of adverse events and implant removal. From January 2001 to December 2015 we conducted a prospective multicenter study of 149 patients who underwent cranioplasty with custom-made PHA flaps after decompressive craniectomy for several reasons. The endpoints were the incidence of adverse events after cranioplasty and of related implant removal. 66 patients (44%) were treated within 6 months from decompression, and only 2 patients had a bifrontal bilateral reconstruction. Of those, 25 patients reported complications (16.8%), and 9 of them (6% of the whole case series) required removal of the prosthesis. The only significant factor predicting cranioplasty removal was a previous infection. Hydroxyapatite for cranial implants is fully comparable to other heterologous materials. It has a biologic potential of bony integration. The risk of explants seems to be significantly higher in second-line patients, data not shown in previous studies.

Prepectoral implant placement in plastic-reconstructive breast surgery – a contribution to the discussion

AbstractImplant-based breast reconstruction has gained a high and increasing level of importance both nationally and internationally in recent years and covers a wide spectrum of reconstruction techniques. The standard procedure in nipple-sparing subcutaneous mastectomies is currently performed by placing the implant into a subpectoral pocket beneath the pectoralis muscle. The use of implant-based reconstructive techniques with the need for internal support to reconstruct the inframammary fold, to cover the implant at the lower pole and to provide a stable but flexible implant position has become relevant and led to the introduction of heterologous materials such as acellular dermal matrices and synthetic meshes. Although the safety and aesthetics of this approach have produced good results, prepectoral techniques add a whole new dimension with the development of the next generation of acellular dermal matrices and, especially, titanised implant pockets created specifically for prepectoral implant placement 1 have brought about a renaissance in muscle-sparing reconstructive techniques. These preserve the natural anatomy, thereby avoiding the adverse effects associated with submuscular reconstruction, including preservation of full shoulder function, minimising postoperative pain and the risk of bleeding and haematoma, and animation deformities such as “jumping breast phenomenon”. A new method of implant-based breast reconstruction is therefore available and must be analysed regarding indications and benefits.

“Tumulus” stabilization of a total ossicular replacement prosthesis

Functional failure of total ossicular replacement prostheses (TORP) is often due to secondary displacement, ranging from simple subluxation to prosthesis extrusion following recurrence of severe tympanic membrane retraction. Several surgical techniques have been proposed to stabilize a TORP, mostly using superimposed non-organic or resorbable heterologous materials. We describe a simple so-called “tumulus” surgical technique that limits prosthesis displacement and extrusion, regardless of the type of TORP, by using a few fragments of autologous cartilage that are always available and perfectly tolerated at no cost. Review of 31 cases treated by this technique did not reveal any cases of prosthesis displacement and only one case (3.2%) of prosthesis extrusion with audiometric results comparable to the best results reported in the literature.

Combining high-resolution cryo-electron microscopy and mutagenesis to develop cowpea mosaic virus for bionanotechnology.

Particles of cowpea mosaic virus (CPMV) have enjoyed considerable success as nanoparticles. The development of a system for producing empty virus-like particles (eVLPs) of the virus, which are non-infectious and have the potential to be loaded with heterologous material, has increased the number of possible applications for CPMV-based particles. However, for this potential to be realised, it was essential to demonstrate that eVLPs were accurate surrogates for natural virus particles, and this information was provided by high-resolution cryo-EM studies of eVLPs. This demonstration has enabled the approaches developed for the production of modified particles developed with natural CPMV particles to be applied to eVLPs. Furthermore, a combination of cryo-EM and mutagenic studies allowed the development of particles which are permeable but which could still assemble efficiently. These particles were shown to be loadable with cobalt, indicating that they can, indeed, be used as nano-containers.

Efficacy and safety of durotomy after decompressive hemicraniectomy in traumatic brain injury.

Decompressive hemicraniectomy (DH) plus duroplasty was demonstrated to be effective for treating critically elevated intracranial pressure (ICP). In order to shorten operation time and to avoid the use of autologous or heterologous material, durotomy has been introduced as an alternative to duroplasty. Only limited data is available on the effect of DH and durotomy on the increased ICP in traumatic brain injury (TBI). Therefore, we collected consecutive intraoperative ICP readings during the different steps of DH and durotomy in TBI patients. Eighteen patients with TBI and uncontrollable ICP increase (measured by either an intraparenchymal or an intraventricular ICP probe) underwent DH and durotomy. ICP readings as well as mean arterial blood pressure (MAP) and arterial PCO2 were obtained during defined stages of the operation. Surgical complications of the durotomy itself and of cranioplasty after 3months were recorded. The outcome was assessed prior to cranioplasty using the Glasgow Outcome Scale (GOS). ICP dropped significantly during surgery from a mean of 41 (±16.2) mmHg at the beginning to a mean of 11.8 (±7.5) mmHg at the end (p≤0.001). A first significant ICP-decrease to a mean of 18 (±10.8) mmHg (p≤0.001) was detected after removal of the bone flap, and a second significant ICP-decrease to a mean of 10.6 (±5.3) mmHg (p<0.001) during durotomy. The mean operation time was 115.3min (±49.6). Five patients (28%) died; seven patients (39%) had a good outcome (GOS 5). There were no relevant complications associated to durotomy. Durotomy after DH is a safe and straightforward procedure, which significantly lowers critically increased ICP in patients with TBI. Although no graft is used, dural preparation for cranioplasty at 3months is easily possible.

Protein crystal nucleation in pores

The most powerful method for protein structure determination is X-ray crystallography which relies on the availability of high quality crystals. Obtaining protein crystals is a major bottleneck, and inducing their nucleation is of crucial importance in this field. An effective method to form crystals is to introduce nucleation-inducing heterologous materials into the crystallization solution. Porous materials are exceptionally effective at inducing nucleation. It is shown here that a combined diffusion-adsorption effect can increase protein concentration inside pores, which enables crystal nucleation even under conditions where heterogeneous nucleation on flat surfaces is absent. Provided the pore is sufficiently narrow, protein molecules approach its walls and adsorb more frequently than they can escape. The decrease in the nucleation energy barrier is calculated, exhibiting its quantitative dependence on the confinement space and the energy of interaction with the pore walls. These results provide a detailed explanation of the effectiveness of porous materials for nucleation of protein crystals, and will be useful for optimal design of such materials.

A novel equine-derived pericardium membrane for dural repair: A preliminary, short-term investigation.

Background:A large variety of biological and artificial materials are employed in dural repair, each of them with major limitations. Autologous grafts have limited availability and require an additional incision and surgical time. Cadaveric preparations and heterologous materials entail the risk of iatrogenic transmission of prions, whereas synthetic substitutes have been reported to cause inflammatory reactions and graft rejection. An equine-derived pericardium membrane has been developed (Heart®, Bioteck, Vicenza, Italy) with mechanical and safety-related features that could make it suitable for neurosurgical application.Aims:This preliminary study aimed to evaluate the short-term safety and efficacy of the Heart® membrane in dural repair procedures following meningioma surgeries.Subjects and Methods:Medical records of patients who were surgically treated for an intracranial meningioma and underwent duraplasty with the Heart® membrane were reviewed retrospectively. The occurrence of any graft-related complications such as cerebrospinal fluid (CSF) leakage, postoperative hematoma, wound infection, meningitis, and neurological symptoms was analyzed.Results:Eight patients were identified as meeting the inclusion criteria. A watertight closure was achieved in all of them. Postoperatively, no patients exhibited CSF leak, cerebral contusion, hemorrhage, or wound infection. The 1-month radiological follow-up revealed no evidence of pseudomeningocele, wound breakdown, or meningitis. Neurologic complications were observed in three patients but not directly imputable to the dural substitute or its application.Conclusions:In all the patients, the pericardium membrane enabled achievement of a watertight dural closure without graft-related adverse events. Further investigations should be performed to assess medium- and long-term clinical outcomes in a larger set of patients.

Superior vena cava resection and reconstruction

Stage III thymic tumours often represent a major challenge; however, if complete resection is accomplished, long-term survival can be comparable with that of patients with stage I and II disease [1]. Induction and adjuvant regimens may help us to achieve these results [2]. The left brachiocephalic vein, superior vena cava (SVC), right atrium, pericardium, lung and diaphragm can be safely resected with or without reconstruction. Also, resection of one phrenic nerve or reconstruction of the ascending aorta and main pulmonary artery may be required to achieve complete resection; on the other hand, invasion through the pericardium into the myocardium usually precludes resection. Vascular reconstructions certainly pose more serious technical problems. The SVC, the brachiocephalic vein(s) and also the right atrium can be resected and reconstructed, but only if it helps to achieve complete resection. If the SVC is infiltrated for <30% of the circumference, partial resection of the wall of the vessel is usually feasible, and repair can be accomplished either by direct suture or patch reconstruction; autologous (pericardial or venous) or heterologous material (bovine pericardium) is usually employed. If a larger circumferential involvement is present, complete resection of the vessel with prosthetic reconstruction is required. This is usually accomplished by synthetic grafts [rigid polytetrafluoroethylene (PTFE)] or a tube of bovine pericardium [3, 4]; the latter allows excellent long-term patency without anticoagulation. These operations represent a major technical challenge for the potential detrimental effect of clamping a patent vessel [5] and the risk of complications. Partial or complete SVC clamping of a chronically obstructed vessel is usually well tolerated. On the other hand, if complete clamping of a patent SVC is required, a marked haemodynamic imbalance may occur, with consequent increase of the mean venous pressure in the cephalic district and a reduced arterial—venous gradient within the brain. This may result in cerebral oedema, haemorrhage and damage, and potentially intra-operative lethal reduction in cardiac output. The haemodynamic derangement may be limited by a dedicated pharmacologic support, adequate intra-operative strategy and intra—or extraluminal shunt placement. Difficult situations with direct invasion of the right atrium or intracaval—intra-atrial involvement (with or without a neoplastic thrombus) usually require the institution of cardio-pulmonary bypass (CPBP) [6–8]. In fact, transient shunts bypassing the SVC and redirecting blood flow directly into the right atrium might not be technically feasible or may not be appropriate in these situations, since the atrium must be kept empty to allow removal of both the tumour and the endovascular neoplastic thrombus with safe reconstruction. In this issue, Toker et al. describe an interesting technique [9] allowing transient cava-pulmonary shunt with complete by pass of the circulation draining in the inferior vena cava (IVC) directly into the pulmonary artery. Systemic heparinization was not required. The Trendelemburg position and the IVC pressure itself allow flow without haemodynamic instability. This shunt is easy to set and does not pose major technical problems. In the present case, it also took advantage of the complete obstruction of the SVC and left brachiocephalic vein clearly evident preoperatively; in fact, chronic obstruction of the upper caval system has probably already favoured the onset of collaterals contributing to drain blood from one venous system to the other. However, CPBP should not be regarded any more as a detrimental option in these patients. Clamping time is usually short; the use of pre-heparinized circuits dramatically reduces the need for systemic heparinization and reduces the risk of intraand post-operative complications, particularly bleeding. This is nowadays clear and it has been extensively described during lung transplantation, where CPBP is instituted much more liberally [10]. CPBP should be part of the armamentarium of thoracic surgeons and we should be ready to institute it, also with the cooperation of cardiac surgeons, if required. If less invasive options are technically feasible they should be taken into consideration without adding major risks.

Complex vesico-vaginal fistula repair with posterosuperior bladder flap

Introduction: Vesicovaginal fistulae (VVF) remain one of the most challenging problems in modern female urology. VVF are classified as simple and complex. Complex fistulae are fistulae of large size (greater than or equal to 3 cm in diameter); those recurring after prior attempts at closure; those associated with a history of prior radiation therapy or with malignancy; those occurring in a compromised operative field owing to poor healing or host characteristics and those involving the trigone, bladder neck and/or urethra. Materials and Methods: From November 1985 to September 2010, 58 cases of VVF were repaired at our institution with the Gil-Vernet technique, without the necessity of interposition of any autologous or heterologous material. We present the case of a 44-year old woman with a previous history of cesarean, who presented with vaginal urine leakage after bladder injury with an initial attempt of primary closure during laparoscopic hysterectomy for uterine myoma. This video describes the VVF repair using a autoplasty closure with posterosuperior vesical flap “The GilVernet technique. Results: In 99.41% cases closure of the fistula was achieved at the first sur gical attempt. Conclusion: In our experience, the Gil-Vernet technique has been successful in most cases and we recommend this technique for repair of complex VVF.

Graft-free Ahmed tube insertion: a modified method at 5 mm from limbus

To determine the medium-term outcome of Ahmed implants inserted through a needle tract at 5 mm from limbus that eliminates the need for a donor scleral graft. A retrospective case series of 19 patients undergoing Ahmed implant surgery for refractory glaucoma with a mean follow-up of 12 months. Primary outcome measures included control of intraocular pressure after surgery. Secondary outcome measure included the frequency of intraoperative and postoperative complications. Intraocular pressure was maintained between 6 and 21 mmHg throughout the study. There was no postoperative hypotony. There were no complications related to this modified technique. Needle tract at 5 mm from limbus maintains implant's ability to control intraocular pressure and eliminates the need for a donor scleral graft or heterologous material.