Ultra-high-frequency ultrasound (48-70 MHz) is a promising tool for improved gastrointestinal diagnostics in infants.

AIM: To investigate the clinical feasibility of ultra-high-frequency abdominal ultrasound (UHFUS) scans of preterm and term infants. METHODS: Prospectively, 19 healthy term newborn infants were examined with conventional ultrasound (CUS) (Toshiba, Aplio i700, linear probe 14L5) and UHFUS (Visualsonics VevoMD, linear probes UHF48 and UHF70) according to a standardised protocol. Measurements of wall thickness were performed for; stomach, small intestine, colon and peritoneum. Five preterm infants, with or without suspected necrotising enterocolitis (NEC), were also examined with UHF48. Of these, only one was later diagnosed with NEC. RESULTS: Differences between CUS and UHFUS (UHF48) were found in measurements of thickness; for peritoneum 0.25 versus 0.13 mm (p < 0.001), small intestine 0.76 versus 0.64 mm (p = 0.039) and colon 0.7 versus 0.47 mm (p < 0.001) in healthy term infants. Gaining frequency from 46 to 71 MHz showed a mean reduction in measurements of peritoneum from 0.13 to 0.09 mm (p < 0.001). One preterm infant with NEC showed a fivefold and twofold increase in peritoneal and gastrointestinal wall thickness respectively, compared to healthy preterm infants. CONCLUSION: UHFUS was a clinically feasible, promising method with potential to improve gastrointestinal diagnostics in infants. Lower peritoneum thickness and gastrointestinal wall thickness were demonstrated with UHFUS compared to CUS, suggesting an overestimation by CUS.

Extragastrointestinal Stromal Tumor in the Peritoneum: A Case Report.

Gastrointestinal stromal tumors (GIST) are tumors of mesenchymal origin, accounting for less than 1% of the primary neoplasms of the digestive tract, which can affect any segment of the gastrointestinal tract. However, they can also occur in other locations outside the gastrointestinal tract. In such situations, these are known as extragastrointestinal stromal tumors (eGIST). We present a 58-year-old male, who attended the emergency department due to asthenia, anorexia, heartburn, abdominal pain, and distension, who was ultimately diagnosed with an eGIST in the peritoneum. The immunohistochemistry pattern of the tumor sample obtained favored this diagnosis, especially demonstrated by the positivity for discovered on GIST protein 1 (DOG1) and negativity of smooth muscle markers. Due to the rarity of extragastrointestinal tumors and the even greater rarity of those originating in the peritoneum, the authors consider this a pertinent clinical case to be published due to its originality.

[Our innovations for the reduction of postoperative pancreatic fistula output]. / A posztoperatív pancreasfistula csökkentésére bevezetett innovációink.

Bevezetés: A posztoperatív pancreasfistula mind proximalis, mind distalis pancreatectomia után a legjelentosebb sebészi szövodménynek számít. A szakirodalomban nincs egyértelmuen ajánlott, megbízható módszer ezen probléma kiküszöbölésére, emiatt történnek újítások szerte a világon. Jelen közleményünkben a technikai innovációinkról számolunk be. Anyag és módszerek: 2013. január 1-jétol 2023. november 30-ig terjedo idoszakban 205 Whipple-mutétet végeztünk nyitottan, mely során a pancreatojejunalis anastomosist az általunk módosított dohányzacskó-öltéses módszerrel készítettük el. 2019. január 1. és 2023. november 30. között pedig 30 betegnél történt nyitott distalis pancreatectomia, amikor a pancreascsonkot az általunk kifejlesztett technikával, szabad rectus fascia-peritoneum grafttal fedtük, majd azt cirkuláris öltéssel rögzítettük. Közleményünkben ezen két módszerrel elért eredményeket ismertetjük. Eredmények: a demográfiai adatok megfeleltek a betegségnél szokásosnak. A posztoperatív ápolási ido és a transzfúzió igény terén észlelt különbségek tükrözték a kétféle beavatkozás eltéro invazivitását. A releváns pancreasfistula kialakulási rátája kedvezo képet mutatott, Whipple-mutét után 7,3% volt, míg distalis pancreatectomát követoen nem fejlodött ki. A reoperációs és a halálozási arányok megfeleltek az elvártaknak és korreláltak a mutétek kiterjedtségével. Következtetés: pancreas resectiók utáni komplikációk csökkentésére tett törekvéseink során a módosított dohányzacskó-öltéses pancreatojejunostomia és a pancreascsonk fedésére kidolgozott módszerünk egyaránt kedvezo eredményekkel járt.

Tension Pneumoperitoneum: A Rare Complication of Cardiopulmonary Resuscitation (CPR).

Tension pneumoperitoneum is a surgical emergency. Although rare, failure to diagnose and treat the condition may be lethal. Hence, being aware of this phenomenon, particularly in scenarios involving cardiopulmonary resuscitation (CPR), is important. Existing literature emphasises immediate abdominal needle decompression as the initial management followed by close monitoring and keeping a low threshold for surgical intervention as a definitive measure. We decided to write up this case report to raise awareness that a tension pneumoperitoneum can result as a complication of CPR, a well-known and widely practiced algorithm.

Pneumo-peritoneum, pneumo-retroperitoneum and subcutaneous emphysema following endoscopic retrograde cholangiopancreatography with sphincterotomy-an uncommon complication case report.

Endoscopic retrograde cholangiopancreatography (ERCP) is invasive for pancreaticobiliary diseases. Perforation is a rare but severe complication among its associated risks. A 45-year-old female with biliary colic and multiple gallbladder calculi was diagnosed with choledocholithiasis based on imaging showing CBD dilation and gallstones. ERCP was planned for stone removal. Sphincterotomy was performed, but stone retrieval attempts failed, leading to severe pneumo-peritoneum and respiratory compromise. Immediate CBD stenting was done, avoiding surgical intervention. The patient recovered uneventfully, later undergoing laparoscopic cholecystectomy with CBD exploration and stone removal. ERCP-related perforations, rare but severe, involve retroperitoneal air collection. Clinical signs include abdominal discomfort, and imaging confirms diagnosis. Management varies by type, with some requiring surgical repair. Conservative management sufficed in this case, with successful patient recovery. ERCP-related complications like pneumo-peritoneum require prompt diagnosis and conservative management if no perforation is evident.

Navigating the labyrinth of peritoneal and extraperitoneal anatomy: abdominal spread made easy with a case based review.

Essential to understanding disease spread in abdomen is to separate the peritoneum from the extraperitoneum. These areas have distinct anatomy with well-define separate pathways. The peritoneum is comprised of connected recesses that are potential spaces, normally not imaged except when containing excess fluid or air. Peritoneal recesses are formed by the opposing peritoneal surfaces and subdivided by the attachments of the ligaments and mesenteries to the parietal peritoneum. Disease flows within the recesses by changes in abdominal pressure. This forms a distinct spread pattern. The extraperitoneum is traditionally stratified by the renal fascia into the anterior and posterior pararenal spaces and the perirenal space. The fascia contains and directs spread from the contained organs with the compartments. Each space has a unique spread pattern defined by the containing fascia. The extraperitoneum is connected to the mesenteries and ligaments forming the subperitoneal space. This space interconnects the extraperitoneum with the mesenteries allowing for the normal continuum of blood vessels, lymphatics, and nerves but also forms the pathways for bidirectional spread of disease.

[RENAPE network: Towards more equitable access to care and expertise for patients with rare peritoneal cancers]. / Réseau RENAPE : vers une meilleure équité d'accès aux soins et à l'expertise pour les patients atteints de cancers rares du péritoine.

Since its creation in 2010, the progressive structuration of the RENAPE network (Réseau national de prise en charge des tumeurs rares du péritoine) supported by the "Institut national du cancer" and the "Direction générale de l'offre de soins", allowed the optimization of the healthcare system involved in the management of the rare cancers of the peritoneum. In this setting, the RENA-PATH group has also been reinforced, notably by its recognized diagnostic expertise in pathology and its interface with the MESOPATH group. Moreover RENAPE and RENA-PATH led to guidelines diffusion through the integration, in 2019, to the ``Thesaurus National de Cancérologie Digestive'' (TNCD) and to post-university medical education programs. The aim of this article is to highlight the missions of the RENAPE and RENA-PATH, notably the equity in terms of expertise, access to the networks and their improvement in the management of peritoneal diseases.

Safety, Efficacy, and Cost-effectiveness of Organ Suspension in Laparoscopic Gynecologic Surgery: A Retrospective Cohort Study to Validate an Innovative Technique: Laparoscopic Organ Suspension sec. Angioni.

OBJECTIVES: This study aims to evaluate the safety, efficacy, and cost-effectiveness of the Laparoscopic Organ Suspension (OS) sec. Angioni, an innovative approach to transient OS in laparoscopic gynecological procedures. Recognizing the need to enhance surgical site access and overcome limitations of existing organ retraction methods, the study investigates a novel, in-theater constructed OS device. DESIGN: This retrospective observational study was conducted from March 2019 to May 2021 and included 330 patients who underwent multiport or single-site-port laparoscopic surgery employing Angioni's technique for transient pelvic OS. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants included individuals undergoing surgery for conditions such as endometriosis, ovarian cancer, endometrial cancer, pelvic prolapse, and benign ovarian cysts. The Laparoscopic OS sec. Angioni utilizes a segment of a Foley catheter connected to a Polyglactin suture to provide adjustable tension, minimizing the need for reconfiguration during surgery. RESULTS: The application of this OS technique resulted in an average suspension time of 1.9 min, with no significant difference between senior and junior surgeons. The method proved more time-efficient for posterior peritoneum suspension than other published methods and showed no additional risks of organ damage, bleeding, conversion to laparotomy, or OS-related complications. The secondary outcomes revealed reduced hospital stays and minimal blood loss, highlighting the procedure's overall efficiency. LIMITATIONS: Given its retrospective and single-center nature, the study's results may not be widely generalizable. Prospective multicentric comparative studies are recommended to further validate Angioni's technique. CONCLUSIONS: Laparoscopic OS sec. Angioni is introduced as a straightforward, safe, and cost-effective method that significantly streamlines the surgical process. Its adaptability and ease of use suggest that it could be a valuable addition to current gynecological surgical practices, with potential implications for increasing efficiency and reducing procedural costs. Future studies are required to confirm these results across diverse clinical environments.

Closure of the Peritoneum in Laparoscopic Transabdominal Preperitoneal Inguinal Hernia Repair (TAPP) With Cyanoacrylate Glue in a Microdroplet Device: A Single Surgeon Prospective Comparison vs. Barbed Suture.

Purpose: To describe and compare a peritoneal closure technique using cyanoacrylate glue (Glubran 2®, GEM, Cardiolink SL) with a microdroplet device (Glutack®, GEM, Cardiolink SL) in laparoscopic transabdominal preperitoneal repair (TAPP) of inguinal hernia with the routinely used barbed suture peritoneal closure (V-Lock 3.0, Covidien France). Materials and methods: From January to August 2022, 60 patients undergoing TAPP repair for uni- or bilateral inguinal hernia were randomized into one of two groups. One using as mesh fixation and peritoneal closure the Glutack® device with Glubran 2® cyanoacrylate glue (Glu-close group) and the other using mesh fixation with cyanoacrylate and peritoneal closure with V-lock 3.0 (Sut-close group), with a follow-up of 12 months. Demographic variables, operative time, peritoneal closure time, main surgical findings and main intra- and postoperative complications were analyzed prospectively. Results: 63 patients were included with no losses to follow-up. The mean operative time was 34 min (range 58.25) for the glu-close group and 40 (range 64.25) for the sut-close group, with no conversion (0%) for either group. The mean flap closure time was 1.18 min (SD 24 0.19) for the glu-close group and 3.24 min (SD 0.78) for the sut-close group, with statistically significant differences (p < 0.001). The intraoperative complication rate was 0 for the glu-close group and 0 for the sut-close group, with no significant difference. The median hospital stay was 0.8 days (range, 0-1) for both groups. The median duration of follow-up was 12 months and none had hernia recurrence. The postoperative VAS score at the first and second check-up at 1 month and 3 months was 2.83 (SD 1.341) and 0.60 (SD 0.621) in the sut-close group and 1.03 (0.984) and 0.24 (SD 0.435) in the glue-close group, with significant differences (p < 0.001 and p < 0.012). Conclusion: The data demonstrated by the study are that the glue can be used safely to close the peritoneum and that the method provides a small, statistically significant but not clinically relevant reduction in the time to close the peritoneal flap, as well as in postoperative pain after surgery in short and medium term.

Navigating the layers of concern for safe dry needling of the rectus abdominis: a cadaveric study.

OBJECTIVES: To assess needle placement accuracy in the rectus abdominis (RA) muscle during dry needling (DN) without entering the peritoneum. METHODS: Two physical therapists performed DN on a cadaver, making 10 attempts each to needle the RA without entering the peritoneum. Techniques followed two common DN approaches. Ultrasound verified needle depth and safety. RESULTS: Seventy percent of attempts were recorded as safe needle placement, while 30% were unsafe. Accurate RA needle placement without peritoneal entry occurred in 55% of attempts. DISCUSSION/CONCLUSION: Inadvertent peritoneal needle placement during RA DN poses risks regardless of experience. Ultrasound guidance may enhance safety and precision in clinical practice.

Recovery and immune function after low pressure pneumoperitoneum during robot-assisted radical prostatectomy: a randomised controlled trial.

OBJECTIVE: To compare the effectiveness of low intra-abdominal pressure (IAP) facilitated by deep neuromuscular block (NMB) to standard practice in improving the quality of recovery, preserving immune function, and enhancing parietal perfusion during robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS: In this blinded, randomised controlled trial, 96 patients were randomised to the experimental group with low IAP (8 mmHg) facilitated by deep NMB (post-tetanic count 1-2) or the control group with standard IAP (14 mmHg) and moderate NMB (train-of-four 1-2). Recovery was measured using the 40-item Quality of Recovery questionnaire and 36-item Short-Form Health survey. Immune function was evaluated by plasma damage-associated molecular patterns, cytokines, and ex vivo lipopolysaccharide-stimulated cytokine production. Parietal peritoneum perfusion was measured by analysing the recordings of indocyanine-green injection. RESULTS: Quality of recovery was not superior in the experimental group (n = 46) compared to the control group (n = 50). All clinical outcomes, including pain scores, postoperative nausea and vomiting, and hospital stay were similar. There were no significant differences in postoperative plasma concentrations of damage-associated molecular patterns, cytokines, and ex vivo cytokine production capacity. The use of low IAP resulted in better parietal peritoneum perfusion. CONCLUSION: Despite better perfusion of the parietal peritoneum, low IAP facilitated by deep NMB did not improve the quality of recovery or preserve immune function compared to standard practice in patients undergoing RARP.

Laparoscopic extraction of a symptomatic upper abdominal pedunculated parietal peritoneal lipoma arising intermittent abdominal pain: a case report.

INTRODUCTION: Lipomas arising in the parietal peritoneum are rare, and some of them cause abdominal pain due to torsion of the pedunculated peritoneum. We encountered a case of parietal peritoneal lipoma arising upper peritoneum. In this report, we describe the detail of clinical presentation and discuss its potential pathogenesis and treatment strategy. CASE PRESENTATION: 45 year-old Japanese female patient presented with long-lasting intermittent pain in the left upper abdominal region. Abdominal imaging showed a well-defined fatty mass measuring 40 mm in size, suggesting a parietal peritoneal lipoma. Laparoscopy revealed a tumor with a twisted peduncle; however, no adhesion of the surrounding tissues and ischemic changes were visible. The tumor was easily removed by dissection of the tumor pedicle. CONCLUSION: Parietal peritoneal lipoma often shows pedunculated form and it causes abdominal pain by the torsion of tumor pedicle. Therefore, this type of lipoma should be considered a more aggressive surgery.

In vitro 3D microfluidic peritoneal metastatic colorectal cancer model for testing different oxaliplatin-based HIPEC regimens.

Objectives: Treatment of colorectal peritoneal metastases with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) is still evolving. Conducting a randomized trial is challenging due to the high heterogeneity in the presentation of peritoneal disease and various surgical approaches. Biological research may facilitate more rapid translation of information into clinical practice. There is an emerging need for a preclinical model to improve HIPEC treatment protocols in terms of drug doses and treatment durations. The aim of the study is to design a tool that serves as an in vitro three-dimensional (3D) microfluidic peritoneal metastatic colorectal cancer model to test the efficacy of different HIPEC treatments. Methods: We determined the effects of current therapy options using a 3D static disease model on human colon carcinoma cell lines (HCT 116) and transforming growth factor-ß1 induced epithelial-to-mesenchymal transition (EMT) HCT 116 lines at 37 °C and 42 °C for 30, 60, and 120 min. We determined oxaliplatin's half maximal inhibitory concentrations in a 3D static culture by using viability assay. Clinical practices of HIPEC were applied in the developed model. Results: EMT-induced HCT 116 cells were less sensitive to oxaliplatin treatment compared to non-induced cells. We observed increased cytotoxicity when increasing the temperature from 37 °C to 42 °C and extending the treatment duration from 30 to 120 min. We found that 200 mg/m2 oxaliplatin administered for 120 min is the most effective HIPEC treatment option within the framework of clinic applications. Conclusions: The tool map provide insights into creating more realistic pre-clinical tools that could be used for a patient-based drug screening.

A diagnostically challenging case of inflammatory myofibroblastic tumor primary to the peritoneum.

Introduction: Inflammatory myofibroblastic tumors are difficult to diagnose because of the lack of specific indicators. We describe a diagnostically challenging case of an inflammatory myofibroblastic tumor primary to the peritoneum. Case presentation: The patient was a 25-year-old male who presented at our hospital with lower abdominal pain. Computed tomography revealed a mass lesion 80 mm in diameter just above the bladder. This was suspected to be a bleeding tumor of the urachus. Since malignancy could not be ruled out, surgery was planned. This revealed a fragile tumor arising from the peritoneum. Following its removal, the tumor was diagnosed by histopathological analysis as an inflammatory myofibroblastic tumor. Conclusion: We describe a case of inflammatory myofibroblastic tumor primary to the peritoneum diagnosed by histopathology. Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of abdominal wall and anterior bladder tumors.

Comparative Analysis of Nutritional Quality, Serum Biochemical Indices, and Visceral Peritoneum of Grass Carp (Ctenopharyngodon idellus) Fed with Two Distinct Aquaculture Systems.

This study scrutinized the nutritional quality and serum biochemical indices of grass carp (Ctenopharyngodon idellus) cultivated in traditional pond intercropping (TPI) and in-pond raceway system (IPRS) aquaculture setups. The findings showed that the TPI group exhibited a superior water-holding capacity, while the IPRS showcased heightened crude lipid content and levels of textural properties such as springiness. Moreover, significant differences emerged in the fatty acid profiles, with the TPI group manifesting higher total polyunsaturated fatty acids (ΣPUFAs), EPA, DHA, and Σn-3, while the IPRS group exhibited elevated total saturated fatty acids (ΣSFAs). In terms of amino acids, valine and histidine levels were notably higher in the IPRS group, whereas lysine levels were reduced. Volatile compound analysis revealed significant variations, with the IPRS group containing more volatile substances with a better aroma, resulting in a better odor. The IPRS group performed better in serum biochemistry analysis. Additionally, grass carp in the IPRS group displayed an improved structure and greater coverage area of the visceral peritoneum, appearing lighter in color compared to the TPI group. TPI mainly influences nutritional elements; IPRSs primarily affect muscle texture, serum biochemistry, and overall health. This study aims to fill the gap in quality comparison research and provide an important scientific basis.

Inferior vena cava reconstruction with non-fascial autologous peritoneum: Retrospective study and literature review.

BACKGROUND: Inferior vena cava (IVC) resection is essential for complete (R0) excision of some malignancies. However, the optimal material for IVC reconstruction remains unclear. Our objective is to demonstrate the efficacy, safety, and advantages of using Non-Fascial Autologous Peritoneum (NFAP) for IVC reconstruction. To conduct a literature review of surgical strategies for tumors involving the IVC. METHODS: We reviewed all IVC reconstructions performed at our institution between 2015 and 2023. Preoperative, operative, postoperative, and follow-up data were collected and analyzed. RESULTS: A total of 33 consecutive IVC reconstructions were identified: seven direct sutures, eight venous homografts (VH), and 18 NFAP. With regard to NFAP, eight tubular (mean length, 12.5 cm) and 10 patch (mean length, 7.9 cm) IVC reconstructions were performed. Resection was R0 in 89% of the cases. Two patients had Clavien-Dindo grade I complications, 2 grade II, 2 grade III and 2 grade V complications. The only graft-related complication was a case of early partial thrombosis, which was conservatively treated. At a mean follow-up of 25.9 months, graft patency was 100%. There were seven recurrences and six deaths. Mean overall survival (OS) was 23.4 months and mean disease-free survival (DFS) was 14.4 months. According to our results, no statistically significant differences were found between NFAP and VH. CONCLUSIONS: NFAP is a safe and effective alternative for partial or complete IVC reconstruction and has many advantages over other techniques, including its lack of cost, wide and ready availability, extreme handiness, and versatility. Further comparative studies are required to determine the optimal technique for IVC reconstruction.

Laboratory investigation of peritoneal fluids: an updated practical approach based on the available evidence.

Even though analysis of peritoneal fluids (PF) is often requested to medical laboratories for biochemical and morphological tests, there is still no mutual agreement on what the most appropriate way is to manage PF samples and which tests should be appropriately executed. In this update, we tried to identify the most useful tests for PF analysis to establish best practice indications. We performed a literature review and examined available guidelines to select the most appropriate tests by an evidence-based approach. Accordingly, the basic PF profile should include (1) serum to effusion albumin gradient and (2) automated cell counts with differential analysis. This profile allows to determine the PF nature, differentiating between 'high-albumin gradient' and 'low-albumin gradient' effusions, which helps to identify the pathophysiological process causing the ascites formation. Restricted to specific clinical situations, additional tests can be requested as follows: PF lactate dehydrogenase (LDH) and glucose, to exclude (LDH) or confirm (glucose) secondary bacterial peritonitis; PF total protein, to differentiate ascites of cardiac origin from other causes; PF (pancreatic) amylase, for the identification of pancreatic ascites; PF bilirubin, when a choleperitoneum is suspected; PF triglycerides, in differentiating chylous from pseudochylous ascites and PF creatinine, to detect intraperitoneal urinary leakage.

Proteomic analysis of ascitic extracellular vesicles describes tumour microenvironment and predicts patient survival in ovarian cancer.

High-grade serous carcinoma of the ovary, fallopian tube and peritoneum (HGSC), the most common type of ovarian cancer, ranks among the deadliest malignancies. Many HGSC patients have excess fluid in the peritoneum called ascites. Ascites is a tumour microenvironment (TME) containing various cells, proteins and extracellular vesicles (EVs). We isolated EVs from patients' ascites by orthogonal methods and analyzed them by mass spectrometry. We identified not only a set of 'core ascitic EV-associated proteins' but also defined their subset unique to HGSC ascites. Using single-cell RNA sequencing data, we mapped the origin of HGSC-specific EVs to different types of cells present in ascites. Surprisingly, EVs did not come predominantly from tumour cells but from non-malignant cell types such as macrophages and fibroblasts. Flow cytometry of ascitic cells in combination with analysis of EV protein composition in matched samples showed that analysis of cell type-specific EV markers in HGSC has more substantial prognostic potential than analysis of ascitic cells. To conclude, we provide evidence that proteomic analysis of EVs can define the cellular composition of HGSC TME. This finding opens numerous avenues both for a better understanding of EV's role in tumour promotion/prevention and for improved HGSC diagnostics.

Coupling Osmotic Efficacy with Biocompatibility in Peritoneal Dialysis: A Stiff Challenge.

Peritoneal dialysis (PD) is a home-based efficacious modality for the replacement of renal function in end-stage kidney failure patients, but it is still under-prescribed. A major limitation is the durability of the dialytic technique. Continuous exposure of the peritoneum to bioincompatible conventional glucose-based solutions is thought to be the main cause of the long-term morpho-functional peritoneal changes that eventually result in ultrafiltration failure. Poor PD solution biocompatibility is primarily related to the high glucose content, which is not only detrimental to the peritoneal membrane but has many potential metabolic side effects. To improve the clinical outcome and prolong the survival of the treatment, PD-related bioincompatibility urgently needs to be overcome. However, combining dialytic and osmotic efficacy with a satisfactory biocompatible profile is proving to be quite difficult. New approaches targeting the composition of the PD solution include the replacement of glucose with other osmotic agents, and the addition of cytoprotective or osmo-metabolic compounds. Other strategies include the infusion of mesenchymal cells or the administration of orally active agents. In the present article, we review the current evidence on efforts to improve the biocompatible and functional performance of PD, focusing on studies performed in vivo (animal models of PD, human subjects on PD).