[Is the use of virtual reality in otorhinolaryngology teaching automatically positively rated by students? : A questionnaire-based evaluation among students]

BACKGROUND

Analogous to the situation in other disciplines, digital ENT teaching made significant progress during the pandemic. Most ENT clinics nationwide were able to offer a complete virtual teaching program in time. Innovative teaching methods were also used early on. This was recognized in student teaching evaluations. Due to the expansion of virtual reality (VR) in medical teaching, even greater satisfaction should be expected through improved teaching quality.

MATERIALS AND METHODS

Surveys were performed with students (n = 180) of the ENT block internship in the summer semester of 2023. The aim of the evaluation was to determine the students' satisfaction with and subjective effectiveness of the newly implemented VR digital teaching method for teaching ear anatomy and coniotomy. A survey was also carried out among resident physicians.

RESULTS

The ENT teaching was perceived favorably by the students, with an average rating of 11.7 out of 15. The learning effectiveness and the value of VR in the ENT learning portfolio was evaluated varyingly by the students. The physicians' assessment was different, with a more positive perception.

CONCLUSION

Virtual reality represents an innovative component in the teaching portfolio of otolaryngology. This new teaching method is viewed and accepted as a future-oriented tool. Remarkably, the physicians involved voted consistently positively, while the students gave more critical assessments and pointed out limitations in the individual and subjective areas. These findings are in contrast to the further development of innovative teaching methods demanded by student interest groups.

Modified ante situm liver resection without use of cold perfusion nor veno-venous bypass for treatment of hepatic lesions infiltrating the hepatocaval confluence

PURPOSE

Treatment of malignancies invading the hepatic veins/inferior vena cava is a surgical challenge. An ante situm technique allows luxation of the liver in front of the situs to perform tumor resection. Usually, cold perfusion and veno-venous bypass are applied. Our experience with modified ante situm resection relying only on total vascular occlusion is reported.

METHODS

Retrospective analysis on an almost 15-year experience with ante situm resection without application of cold perfusion or veno-venous bypass RESULTS: The ante situm technique was applied on eight patients. Five individuals were treated due to intrahepatic cholangiocellular cancer and one case each for mixed cholangio-/hepatocellular carcinoma, colorectal liver metastasis, and pheochromocytoma. Trisectorectomy (n = 4), left hemihepatectomy, right hepatectomy, atypical resection, or mesohepatectomy (each n = 1) were performed, combined with dissection of suprahepatic/retrohepatic vena cava/hepatic veins. Venous reconstruction was achieved by reimplantation of hepatic veins with/without vascular replacement using allogeneic donor veins or PTFE grafts. Median total vascular occlusion of the liver was 23 min. Severe morbidity occurred in three patients (Dindo-Clavien > 3A). R0 status was achieved in six cases with a median overall survival of 33.5 months.

CONCLUSIONS

Ante situm liver resection can be applied without cold perfusion nor veno-venous bypass with acceptable morbidity and mortality. However, this procedure remains challenging even for the experienced hepato-pancreato-biliary surgeon.

Use of the liver maximum function capacity test (LiMAx) for the management of liver resection in cirrhosis - A case of hypopharyngeal cancer liver metastasis

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A patient with a liver metastasis of pharyngeal cancer and aspect of severe cirrhosis is presented.

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Conventional laboratory tests are surrogate parameters and might underestimate cirrhosis.

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The LiMAx test provides a direct measurement of the liver function capacity even in cirrhosis.

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Safe resection was performed after LiMAx test proved operability.

Introduction

The presence of liver cirrhosis goes along with a higher chance for the need of liver resection. As established laboratory parameters often underestimate the degree of cirrhosis this is associated with an increased risk for postoperative liver failure due to the preoperatively impaired liver function. Known liver function tests are unlikely to be performed in daily use because of high cost or expenditure of time. Liver maximum function capacity test (LiMAx) provides a novel tool for measurement of liver function and references for the safety of liver resection.

Presentation of case

A 63-year old patient presented at our hospital with a large, solitary liver metastasis from hypopharyngeal cancer in segments VII/VIII with infiltration of the diaphragm. Liver resection was unsuccessful in a peripheral hospital 10 months before due to considerable macroscopic liver cirrhosis (CHILD B). Upon presentation conventional laboratory parameters revealed sufficient liver function. LiMAx was performed and showed regular liver function (354 μg/kg/h; at norm >315 μg/kg/h). Consequently, atypical liver resection (R0) was performed resulting in a postoperative LiMAx value of 281 μg/h/kg (>150 μg/kg/h). The patient was discharged from hospital 37 days after surgery without any signs of postoperative liver failure.

Conclusion

The LiMAx-test enables determination of liver function at a so far unavailable level (metabolism via cytochrome P450 1A2) and hence might provide crucial additional diagnostic information to allow for safe liver resection even in cirrhotic patients.

Xeno-kidney transplantation: from idea to reality

Although kidney transplantation is a widely used therapy for chronic renal failure, not all patients can be transplanted due to the limited numbers of organ donations. A possible solution could be xenogenic kidney transplantation. Herein we have described the present state, problems and possible solutions using xenograft treatments.

309 PRODUCTION OF PIGS TRANSGENIC FOR HUMAN HEMEOXYGENASE-I BY SOMATIC NUCLEAR TRANSFER

The hyperacute rejection after porcine-to-human xenotransplantation can now be reliably overcome either by transgenic expression of complement regulating factors or by knocking out the gene for α1,3-galactosyltransferase in pigs. The next immunological hurdle is the acute vascular rejection (AVR) primarily caused by endothelial cell activation. Human hemeoxygenase-I (hHO-I) is known to have anti-apoptotic and cell-protective properties. Thus, the expression of hHO-I on porcine endothelial cells could have beneficial effects in a xenotransplantation setting to prevent the formation of AVR. Here we describe the first transgenic pigs with functional expression of hHO-I. Fibroblasts were obtained by an ear punch from a decay accelerating factor (DAF)-transgenic female pig and were cultured in vitro (Kues WA et al. 2005 Biol. Reprod. 72, 1020–1028). Cells reaching confluency of 70 to 80% were detached with EDTA/trypsin and subsequently transfected by electroporation at 450V/350 µF with a vector coding for hHO-I driven by the SV40 promoter. Transfected cells were selected for resistance against G418 (800 µg mL–1) for 14 days. Resistant cell clones were screened for integration of the vector by PCR. One positive cell clone that showed strong expression of the transgene, as determined by immunostaining, was selected for somatic nuclear transfer (Hoelker M et al. 2005 Cloning Stem Cells 7, 35–44). In total, 205 reconstructed embryos were transferred to 2 synchronized peripuberal German Landrace gilts, which gave birth to 9 live piglets, all with normal birth weights. PCR and Southern blot analyses revealed that all of the offspring had integrated the vector into their genome. Two transgenic animals were sacrificed for further characterization and ex vivo perfusion experiments. In these animals, Northern blotting showed weak transcription of the transgene in all xenorelevant organs such as heart, kidney, and liver. Immunostaining of the kidneys revealed that expression of the transgene was confined to the endothelial cell layer. These hHO-I-transgenic porcine kidneys were subjected to an ex vivo perfusion assay and survived ex vivo perfusion for 240 min with AB-pooled human blood, whereas perfusion of 2 non-transgenic controls had to be terminated after 60 min due to problems attributed to immunological rejection. Histology revealed that perfused hHO-I-transgenic kidneys exhibited no indication for xenogenic activation of the human coagulation system. These preliminary results show that functional hHO-I can be expressed in transgenic pigs and that transgenic expression of hHO-I might improve long-term survival of porcine xenografts. These results are encouraging and warrant further studies on endothelial cell activation and the biological function of hemeoxygenase-I in the context of xenotransplantation. This study was funded by the Deutsche Forschungsgemeinschaft Ni 256/22-1, -2, -3.