[Future of University Medicine: How Important are Research and Teaching? - An Inventory]

The requirements and challenges for the university hospitals in Germany are changing. Especially in surgical subjects, it is more and more difficult to adequately serve these three pillars of university medicine - clinic, research and education. This survey was intended to determine the status quo of general and visceral surgery at universities, in order to provide a basis for proposed solutions.For this online survey, 1505 visceral surgeons at the 38 university clinics were contacted. The questionnaire contained 29 questions on the structure of the clinic, scientific motivation, opportunities for time-off and the appreciation of academic achievements. The type and scope of student courses and the preparation for them were also determined. With regard to patient care, the type and number of services and the course of surgical training were examined. Based on the data published on the websites of the individual clinics on the number, gender, position and academic title of the doctors, a demographic analysis of university visceral surgeons could also be created.Of 1505 surgeons successfully contacted, 352 took part in the survey, which corresponds to a response rate of 23.4%. Of the participants, 93.5% were scientifically active, the majority being in the field of clinical data collection. Many indicated that they were also active in translational and/or experimental research, while educational research was rarely named. 45% confirmed that they could perform scientific work during their normal working hours. The reward for this activity was mostly in the form of time-off for congresses and clinical appreciation. Most participants stated that they were involved in 3-4 student courses per week, with 24.4% reporting that they were not adequately prepared for them.The compatibility of the classic three pillars of clinic, research and teaching continues to be of great relevance. There is a high level of motivation among the participating visceral surgeons not to neglect research and teaching, despite increasing economic pressure in the field of patient care. However, arrangements must be created in order to reward and promote commitment in research and teaching in a structured way.

Education Team Time Out in Oncologic Visceral Surgery Optimizes Surgical Resident Training and Team Communication-Results of a Prospective Trial

BACKGROUND

Surgical education is highly dependent on intraoperative communication. Trainers must know the trainee's training level to ensure high-quality surgical training. A systematic preoperative dialogue (Educational Team Time Out, ETO) was established to discuss the steps of each surgical procedure.

METHODS

Over 6 months, ETO was performed within a time limit of 3 minutes. Digital surveys on the utility of ETO and its impact on performance were conducted immediately after surgery and at the end of the study period among the staff of the participating disciplines (trainer, trainee, surgical nursing staff, anaesthesiologists, and medical students). The number of surgical substeps performed was recorded and compared with the equivalent period one year earlier.

RESULTS

ETO was performed in 64 of the 103 eligible operations (62%). Liver resection (n = 37) was the most frequent procedure, followed by left-sided colorectal surgery (n = 12), partial pancreaticoduodenectomy (n = 6), right-sided hemicolectomies (n = 5), and thyroidectomies (n = 4). Anaesthesiologists most frequently reported that ETO had a direct impact on their work during surgery (90.9%). The influence scores were 46.8% for trainees, 8.8% for trainers, 53.3% for surgical nursing staff and 66.6% for medical students. During the implementation of ETO, a trend towards more assisted substeps in oncologic visceral surgery was seen compared to the corresponding period one year earlier (51% vs.40%; p = 0.11).

CONCLUSION

ETO leads to improved intraoperative communication and more performed substeps during complex procedures, which increases motivation and practical training. This concept can easily be implemented in all surgical specialties to improve surgical education.

[Testing of practical surgical teaching at a distance-Experiences with a hybrid OSCE in surgery]

BACKGROUND

The COVID-19 pandemic has changed medical teaching worldwide. Digital teaching and examinations are successful for cognitive learning objectives, whereas practical skills had to be carried out predominantly in person under strict hygiene standards.

AIM

This study presents the opportunities and challenges of using a presence objective structured clinical examination (OSCE) at a distance with digital support.

METHOD

Following surgical practical teaching an OSCE was conducted in presence, where students demonstrated practical skills in one room while the examiners were connected via videoconference from another room. Students were surveyed about the OSCE and sustained learning via a standardized online questionnaire after completion of the surgical teaching. Additionally, examiners were surveyed on their experiences.

RESULTS

In the online survey 40 students participated (25% of n = 157 students contacted) and 36 completed questionnaires were analyzed. Overall, the implementation of an OSCE even under pandemic conditions was perceived as very positive by the students (92% of students n = 33). In particular, the acquisition of practical skills was rated as very high. For 78% (n = 28) of the students, the acquisition of competencies through the practical examination was particularly sustainable. The vast majority of students and examiners felt safe regarding infection control because of the hygiene concept (92%, n = 33). Overall, 80 students achieved grade 1 (51%), 71 students grade 2 (45.2%) and 6 students grade 3 (3.8%) (grade 1 = very good, grade 6 = very bad).

CONCLUSION

Practical examinations are essential for checking practical learning objectives and can be implemented at a distance with a well-developed hygiene concept and digital support.

[Surgical Education of Medical Students in Times of COVID-19 - Necessary Adjustments are Chances for the Future]

BACKGROUND

Education of medical students in surgery not only consists of knowledge about diseases and their treatment but also of practical skills like i.e. suturing. In the clinical training of medical students, professional interaction and communication with patients is a key component. Due to the circumstances of distancing and reduced exposure to patients during the COVID-19 pandemic, clinical training of medical students has been challenging. To combat these restrictions, digital modern teaching concepts had to be implemented.

MATERIAL AND METHODS

Surgical education of medical students was reorganised during the summer semester 2020 and winter semester 2020/2021 and the necessary adjustments, as well as their evaluation by students, were analysed. Results were compared to the pre-COVID evaluations of the summer semester 2019. Furthermore a survey of all university surgical departments in Germany (n = 39) was conducted to compare the different approaches to handling this very new situation.

RESULTS

All participating centres were performing surgical education with medical students during the COVID-19 pandemic. Overall, digital teaching methods were well accepted by students and teachers, even though short-term changes were necessary during the second wave of the pandemic. Both students and teachers missed the direct mutual interaction as well as with patients (summer semester 2020 36%, winter semester 2020/2021 40%). Modern and digital teaching concepts were assessed positively (summer semester 2020 45%, winter semester 2020/2021 40%) and long term implementation was desired by students and teachers (winter semester 2020/2021 60%).

CONCLUSION

Training of practical surgical skills, as well as communication skills, can only be taught in presence. Digital learning concepts can support, but not replace, surgical courses held in presence, including contact to patients and manual training. Blended learning concepts facilitate a leap towards modern teaching concepts and increase the quality of classes spent in presence.

Comparative analysis of nuclear and mitochondrial DNA from tissue and liquid biopsies of colorectal cancer patients

The current standard for molecular profiling of colorectal cancer (CRC) is using resected or biopsied tissue specimens. However, they are limited regarding sampling frequency, representation of tumor heterogeneity, and sampling can expose patients to adverse side effects. The analysis of cell-free DNA (cfDNA) from blood plasma, which is part of a liquid biopsy, is minimally invasive and in principle enables detection of all tumor-specific mutations. Here, we analyzed cfDNA originating from nucleus and mitochondria and investigated their characteristics and mutation status in a cohort of 18 CRC patients and 10 healthy controls using targeted next-generation sequencing (NGS) and digital PCR. Longitudinal analyses of nuclear cfDNA level and size during chemotherapy revealed a decreasing cfDNA content and a shift from short to long fragments, indicating an appropriate therapy response, while shortened cfDNAs and increased cfDNA content corresponded with tumor recurrence. Comparative NGS analysis of nuclear tissue and plasma DNA demonstrated a good patient-level concordance and cfDNA revealed additional variants in three of the cases. Analysis of mitochondrial cfDNA surprisingly revealed a higher plasma copy number in healthy subjects than in CRC patients. These results highlight the potential clinical utility of liquid biopsies in routine diagnostics and surveillance of CRC patients as complementation to tissue biopsies or as an attractive alternative in cases where tissue biopsies are risky or the quantity/quality does not allow testing.

Rating of camera navigation skills in colorectal surgery

PURPOSE

In advanced minimally invasive surgery the laparoscopic camera navigation (LCN) quality can influence the flow of the operation. This study aimed to investigate the applicability of a scoring system for LCN (SALAS score) in colorectal surgery and whether an adequate scoring can be achieved using a specified sequence of the operation.

METHODS

The score was assessed by four blinded raters using synchronized video and voice recordings of 20 randomly selected laparoscopic colorectal surgeries (group A: assessment of the entire operation; group B: assessment of the 2nd and 3rd quartile). Experience in LCN was defined as at least 100 assistances in complex laparoscopic procedures.

RESULTS

The surgical teams consisted of three residents, three fellows, and two attendings forming 15 different teams. The ratio between experienced and inexperienced camera assistants was balanced (n = 11 vs. n = 9). Regarding the total SALAS score, the four raters discriminated between experienced and inexperienced camera assistants, regardless of their group assignment (group A, p < 0.05; group B, p < 0.05). The score's interrater variability and reliability were proven with an intraclass correlation coefficient of 0.88. No statistically relevant correlation was achieved between operation time and SALAS score.

CONCLUSION

This study presents the first intraoperative, objective, and structured assessment of LCN in colorectal surgery. We could demonstrate that the SALAS score is a reliable tool for the assessment of LCN even when only the middle part (50%) of the procedure is analyzed. Construct validity was proven by discriminating between experienced and inexperienced camera assistants.

Gas-Liquid Chromatographic Determination of Milk Fat and Cocoa Butter Equivalents in Milk Chocolate: Interlaboratory Study

A collaborative trial was conducted to validate an analytical approach comprising method procedures for determination of milk fat and the detection and quantification of cocoa butter equivalents (CBEs) in milk chocolate. The whole approach is based on (1) comprehensive databases covering the triacylglycerol composition of a wide range of authentic milk fat, cocoa butter, and CBE samples and 947 gravimetrically prepared mixtures thereof; (2) the availability of a certified cocoa butter reference material for calibration; (3) an evaluation algorithm, which allows reliable quantitation of the milk fat content in chocolate; (4) a subsequent correction to take account of the triacylglycerols derived from milk fat; (5) mathematical expressions to detect the presence of CBEs in milk chocolate; and (6) a multivariate statistical formula to quantitate the amount of CBEs in milk chocolate. Twelve laboratories participated in the validation study. CBE admixtures were detected down to a level of 0.5 g CBE/100 g milk chocolate, without false-positive or -negative results. The applied quantitation model performed well at the statutory limit of 5 CBE addition to milk chocolate, with a prediction error of 0.7, and HorRat values ranging from 0.8 to 1.5. The relative standard deviation for reproducibility (RSDR) values for quantitation of CBEs in analyses of chocolate fat solutions ranged from 2.2 to 3.8 and for analyses of real chocolate samples, from 4.1 to 4.7, demonstrating that the whole approach, based solely on chocolate fat blends, is applicable to real milk chocolate samples.

Method Validation for Detection and Quantification of Cocoa Butter Equivalents in Cocoa Butter and Plain Chocolate

A European interlaboratory study was conducted to validate an analytical procedure for the detection and quantification of cocoa butter equivalents in cocoa butter and plain chocolate. In principle, the fat obtained from plain chocolate according to the Soxhlet principle is separated by high-resolution capillary gas chromatography into triacylglycerol fractions according to their acyl-C-numbers, and within a given number, also according to unsaturation. The presence of cocoa butter equivalents is detected by linear regression analysis applied to the relative proportions of the 3 main triacylglycerol fractions of the fat analyzed. The amount of the cocoa butter equivalent admixture is estimated by partial least-squares regression analysis applied to the relative proportions of the 5 main triacylglycerols. Cocoa butter equivalent admixtures were detected down to a level of 2% related to the fat phase, corresponding to 0.6% in chocolate (assumed fat content of chocolate, 30%), without false-positive or -negative results. By using a quantification model based on partial least-squares regression analysis, the predicted cocoa butter equivalent amounts were in close agreement with the actual values. The applied model performed well at the level of the statutory limit of 5% cocoa butter equivalent addition to chocolate with a prediction error of 0.6%, assuming a chocolate fat content of 30%.

[Diagnostic ability of power measurement of different grip forms for distal median nerve lesion]

BACKGROUND

Peripheral lesions of the median nerve cause characteristic changes of the grip function of the hand. For evaluating grip force changes, measurement by dynamometers (JAMAR dynamometer and pinch dynamometer) is of high relevance. In this study the ability of grip force measurements of different grip forms was evaluated to discriminate between a simulated median nerve lesion and healthy subjects.

MATERIAL AND METHODS

In 21 healthy subjects, the grip force of power grip was measured by the JAMAR dynamometer at the second stage including measurement of force at the fingertips and the thenar by a sensor glove. With a pinch dynamometer the power of palmar abduction, precision grip, pincer grip and pinch grip was determined. Measurements were performed with and without median nerve block at the wrist.

RESULTS

In power grip of the JAMAR dynamometer at the second stage a significant reduction of the grip force of 13.4% was found (p < 0.03). The power distribution between the fingers D2-D5 did not change with median nerve block. The most relevant reduction of grip force in median nerve block compared with the healthy control was measured in palmar abduction (72.1%, p < 0.0002), followed by precision grip 31.0% (p < 0.0001), pincer grip 23.6% (p < 0.0004) and pinch grip 18.8% (p < 0.0002).

CONCLUSIONS

For the discrimination between healthy subjects and subjects with a median nerve block there was a limited relevance of the measurement of the power grip and force distribution at the fingers by the JAMAR dynamometer. However, the best distinction was observed by dynamometric measurement of other grips than power grip, such as palmar abduction, precision grip, pincer grip and pinch grip. The results could be relevant for the clinical diagnostics and rehabilitation of median nerve lesion, complementing the widespread measurement of the power grip by other grip forms.

Transanal minimally invasive surgery (TAMIS) approach for large juxta-anal gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GISTs) are rarely found in the rectum. Large rectal GISTs in the narrow pelvis sometimes require extended abdominal surgery to obtain free resection margins, and it is a challenge to preserve sufficient anal sphincter and urogenital function. Here we present a 56-year-old male with a locally advanced juxta-anal non-metastatic GIST of approximately 10 cm in diameter. Therapy with imatinib reduced the tumour size and allowed partial intersphincteric resection (pISR). The patient underwent an electrophysiology-controlled nerve-sparing hybrid of laparoscopic and transanal minimally invasive surgery (TAMIS) in a multimodal setting. The down-to-up approach provided sufficient dissection plane visualisation and allowed the confirmed nerve-sparing. Lateroterminal coloanal anastomosis was performed. Follow-up showed preserved urogenital function and good anorectal function, and the patient remains disease-free under adjuvant chemotherapy as of 12 months after surgery. This report suggests that the TAMIS approach enables extraluminal high-quality oncological and function-preserving excision of high-risk GISTs.

Surface Electromyography Reliably Records Electrophysiologically Evoked Internal Anal Sphincter Activity: A More Minimally Invasive Approach for Monitoring Extrinsic Innervation

BACKGROUND

Even in the case of minimally invasive pelvic surgery, sparing of the autonomic nerve supply is a prerequisite for maintaining anal sphincter function. Internal anal sphincter (IAS) innervation could be electrophysiologically identified based on processed electromyographic (EMG) recordings with conventional bipolar needle electrodes (NE). This experimental study aimed for the development of a minimally invasive approach via intra-anal surface EMG for recordings of evoked IAS activity.

METHODS

Six male pigs underwent nerve-sparing low anterior rectal resection. Electric autonomic nerve stimulations were performed under online-processed EMG of the IAS. EMG recordings were simultaneously carried out with conventional bipolar NE as the reference method and newly developed intra-anal surface electrodes (SE) in different designs.

RESULTS

In all experiments, the IAS activity could be continuously visualized via EMG recordings based on NE and SE. The median number of bipolar electric stimulations per animal was 27 (range 5-52). The neurostimulations resulted in significant EMG amplitude increases for both recording types [NE: median 3.0 µV (interquartile range, IQR 2.8-3.5) before stimulation vs. 7.1 µV (IQR 3.9-13.8) during stimulation, p < 0.001; SE: median 3.6 µV (IQR 3.1-4.3) before stimulation vs. 6.8 µV (IQR 4.8-10.3) during stimulation, p < 0.001].

CONCLUSIONS

Intra-anal SE enabled reliable EMG of electrophysiologically evoked IAS activity similar to the conventional recording via NE. The transfer of the method to access platforms for transanal total mesorectal excision or robotics may offer a practical more minimally invasive approach for monitoring extrinsic innervation.

Electrophysiology-based quality assurance of nerve-sparing in laparoscopic rectal cancer surgery: Is it worth the effort?

BACKGROUND

After low anterior resection for rectal cancer, visual assessment of pelvic autonomic nerve preservation can be difficult due to the complexity of neuroanatomy, as well as surgery- and patient-related factors. The present study aimed to evaluate nerve-sparing quality assurance using the laparoscopic neuromapping (LNM) technique.

METHODS

We prospectively investigated a series of 30 patients undergoing laparoscopic low anterior resection. Nerve-sparing was evaluated both visually and electrophysiologically. LNM was performed using stimulation of pelvic autonomic nerves under simultaneous cystomanometry and processed electromyography of the internal anal sphincter. Urogenital and anorectal functions were evaluated using validated and standardized questionnaires preoperatively, at short-term follow-up, and at mid-term follow-up at a median of 9 months (range 6-12 months) after surgery.

RESULTS

One patient reported new onset of urinary dysfunction, and another patient reported new onset of anorectal dysfunction. Of the 20 sexually active patients, five reported sexual dysfunction. Visual assessment by laparoscopy confirmed complete nerve preservation in 28 of 30 cases. For prediction of urinary and anorectal function, LNM sensitivity, specificity, positive and negative predictive value, and overall accuracy were each 100 %. LNM with combined assessment for prediction of sexual function yielded a sensitivity of 80 %, specificity of 93 %, positive predictive value of 80 %, negative predictive value of 93 %, and overall accuracy of 90 %.

CONCLUSIONS

LNM is an appropriate method for reliable quality assurance of laparoscopic nerve-sparing.

Dynamic aspects during the cylinder grip--flexion sequence of the finger joints analyzed using a sensor glove

The purpose of this study was to assess whether there is a universal pattern of movement of the finger joints while performing a cylinder grip. A sensor glove was used to record the finger joint motion of 48 participants. Our observations showed that when examining the fingers, flexion motion began either at the metacarpophalangeal (MP) or proximal interphalangeal (PIP) joints, with the distal interphalangeal (DIP) joints always last to move (p = 0.0052). The sequence of the joints at the end of the gripping motion was different than at the beginning. Here, the only statistically significant observation was that the DIP joints fully flexed only once the MP joints had flexed fully. Apart from that, it was completely variable which joint reached its final position first or last. The analysis also revealed that synchronization of four identical joints (i.e. the four PIP joints) was significantly higher than synchronization of the 12 finger joints. Although synchronization was already high at the beginning of the flexion motion, it increased significantly by the time the joints completed their movement.

Relevance of primary reduction for the clinical outcome of femoral neck fractures treated with cancellous screws

INTRODUCTION

Femoral head-preserving treatment for femoral neck fractures with cancellous screws is a method widely performed, but its success depends on the quality of primary reduction. The goal of our study was to evaluate the relevance of reduction quality on the clinical outcome.

PATIENTS AND METHODS

We retrospectively analyzed the postoperative reduction result of 39 patients. The angular rotation and the inferior displacement of the proximal fracture fragment were digitally assessed from AP radiographs. The clinical outcome was recorded by a follow-up after a mean 5.5 years.

RESULTS

Unsuccessful healing was observed in eight patients, femoral head necrosis in three patients, non-union in two patients, implant loosening in one patient, and posttraumatic arthritis in two patients, all resulting in the need for a total hip replacement. This clinical course was strongly associated with a primary reduction in varus position, whereas reduction in anatomic or valgus angulation had no negative effect on the clinical outcome. An inferior offset was no negative predictor for successful healing.

CONCLUSION

We conclude that a non-anatomic reduction in varus angulation significantly increases the risk of healing failure and therefore should be avoided. Reduction in valgus position should be performed if secondary redislocation is imminent.

[Evaluation of cartilage changes within the scope of second-look arthroscopy 12 months after surgical reconstruction of anterior cruciate ligament rupture]

The anterior cruciate ligament (ACL) rupture is among the most frequent injuries of the joints. Actually, there is no doubt regarding the necessity for surgical treatment. However, little is known about the progression of osteochondral damages and their distribution following reconstruction of the ACL. We treated 150 tears of the ACL either acute (median 7d) with augmented reinsertion (n = 41) and with autologous bone patella tendon graft (n = 24) or chronic (median 369d) with autologous bone patella tendon graft (n = 85). The study design was prospective. All osteochondral defects were documented in the six compartments. Second look arthroscopy and clinical examination were performed after twelve months in the course of removal of implants and possible changes of the osteochondral state were evaluated. Detoriation of osteochondral state was seen in 86 (57%) of 150 patients, while there was no statistical difference between the three groups. The time of operation had no influence on the osteochondral damage. There was a significant increase of chondral damages in the medial and retropatellar compartment after autologous bone patella tendon graft, while the changes after augmented reinsertion were diffuse. There were no significant differences in the clinical examination between the three groups regarding the Lysholm score and the functional and subjective outcome. However, postoperative instability was frequently observed (positive pivot-shift 25%, positive Lachmann test 57%). We suggest that postoperative instability should have led to the increased osteochondral damages.

First histological observations on the incorporation of a novel calcium phosphate bone substitute material in human cancellous bone

Calcium phosphates are frequently used as bone substitute materials because of their similarity to the mineral phase of bone, absence of antigenicity, and excellent osteoconductivity. However, in most currently available mineral substitutes, resorption occurs slowly if at all. In contrast, calcium phosphate cements have shown rapid resorption and remodeling in animal studies. In two prospective studies, a novel amorphous calcium phosphate cement (Biobon) was implanted in human patients for the first time. After 2-12 months, ten biopsies were obtained from nine individuals during secondary surgical interventions, for example, for implant removal. In all specimens, partial replacement of the material by new bone was observed, while residues of the cement were still visible. Undecalcified sections revealed extensive bone formation in immediate contact to the cement without fibrous interface. Polynucleated cells and superficial lacunae were indicative of resorptive activity, but inflammatory tissue response was absent. The new bone displayed regular trabecular and osteonal patterns. The histologic findings are in accordance with the excellent biocompatibility observed in the clinical follow-up. Though still incomplete, the resorbability of this cement appears superior to sintered calcium phosphates in these biopsy specimens. Presumably this is due to its amorphous crystalline structure. Biobon merits further studies as a promising substance for bone defect reconstruction in non-stress-bearing areas.

Functional treatment of physeal and periphyseal injuries of the metacarpal and proximal phalangeal bones

BACKGROUND/PURPOSE

Hand fractures are common injuries in infants. Complications are rare because of potent remodeling dimension and rapid healing of growing bone. There is limited remodeling capacity for angular and rotational deformity so displaced fractures often require open reduction and internal fixation.

METHODS

The authors present a splint system for a protected reduction and mobilization program of displaced proximal phalanx and metacarpal fractures. The custom-molded 2-component thermoplastic splint allows motion of the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. It has been developed to allow bone healing and recovery of motion at the same time. In this study, the authors evaluated the clinical and radiologic results of a series of 11 consecutive infants with displaced metacarpal fractures and 13 displaced proximal phalanx fractures who received functional treatment.

RESULTS

Fracture consolidation and full active motion was achieved simultaneously in 4 weeks in 21 children; 2 infants required physiotherapy, and 1 child was lost to follow-up. No further growth abnormality was seen within a 12-month observation period.

CONCLUSION

When there is no damage of soft tissue the functional mobilization program can lead to good results treating displaced physeal and periphyseal hand injuries of proximal phalanx and metacarpal fractures. J Pediatr Surg 36:611-615.

[Bacterial coxitis caused by Salmonella enteritidis. Case report and differential diagnostic considerations]

Secondary haematogenous joint involvement is seen in less than 1% of patients with Salmonella infections. These atypical infections are frequently encouraged by pre-existing local or systemic disease. We present a case of a patient with known alcohol abuse who developed a septic infection of her right hip requiring resection of the femoral head. Histologic analysis showed signs of pre-existing osteonecrosis probably induced by alcohol intake. Cartilage and bone were invaded and destructed by an aggressive granulation tissue. Initially, a biopsy evaluated without knowledge of the positive bacteriological result had been interpreted as indicative of a tumour. The onset, clinical course, diagnosis and therapy of joint involvement by Salmonella are discussed with regard to our case and the relevant literature. This case illustrates the necessity for clinicians to share all their information about the patient with the pathologist.