A novel unconventional T cell population enriched in Crohn's disease

OBJECTIVE

One of the current hypotheses to explain the proinflammatory immune response in IBD is a dysregulated T cell reaction to yet unknown intestinal antigens. As such, it may be possible to identify disease-associated T cell clonotypes by analysing the peripheral and intestinal T-cell receptor (TCR) repertoire of patients with IBD and controls.

DESIGN

We performed bulk TCR repertoire profiling of both the TCR alpha and beta chains using high-throughput sequencing in peripheral blood samples of a total of 244 patients with IBD and healthy controls as well as from matched blood and intestinal tissue of 59 patients with IBD and disease controls. We further characterised specific T cell clonotypes via single-cell RNAseq.

RESULTS

We identified a group of clonotypes, characterised by semi-invariant TCR alpha chains, to be significantly enriched in the blood of patients with Crohn's disease (CD) and particularly expanded in the CD8⁺ T cell population. Single-cell RNAseq data showed an innate-like phenotype of these cells, with a comparable gene expression to unconventional T cells such as mucosal associated invariant T and natural killer T (NKT) cells, but with distinct TCRs.

CONCLUSIONS

We identified and characterised a subpopulation of unconventional Crohn-associated invariant T (CAIT) cells. Multiple evidence suggests these cells to be part of the NKT type II population. The potential implications of this population for CD or a subset thereof remain to be elucidated, and the immunophenotype and antigen reactivity of CAIT cells need further investigations in future studies.

The surgical anatomy of a (robot-assisted) minimally invasive transcervical esophagectomy

BACKGROUND

Transcervical esophagectomy allows for esophagectomy through transcervical access and bypasses the thoracic cavity, thereby eliminating single lung ventilation. A challenging surgical approach demands thorough understanding of the encountered anatomy. This study aims to provide a comprehensive overview of surgical anatomy encountered during the (robot-assisted) minimally invasive transcervical esophagectomy (RACE and MICE).

METHODS

To assess the surgical anatomy of the lower neck and mediastinum, MR images were made of a body donor after, which it was sliced at 24-μm intervals with a cryomacrotome. Images were made every 3 slices resulting in 3.200 images of which a digital 3D multiplanar reconstruction was made. For macroscopic verification, microscopic slices were made and stained every 5 mm (Mallory-Cason). Schematic drawings were made of the 3D reconstruction to demonstrate the course of essential anatomical structures in the operation field and identify anatomical landmarks.

RESULTS

Surgical anatomy 'boxes' of three levels (superior thoracic aperture, upper mediastinum, subcarinal) were created. Four landmarks were identified: (i) the course of the thoracic duct in the mediastinum; (ii) the course of the left recurrent laryngeal nerve; (iii) the crossing of the azygos vein right and dorsal of the esophagus; and (iv) the position of the aortic arch, the pulmonary arteries, and veins.

CONCLUSIONS

The presented 3D reconstruction of unmanipulated human anatomy and schematic 3D 'boxes' provide a comprehensive overview of the surgical anatomy during the RACE or MICE. Our findings provide a useful tool to aid surgeons in learning the complex anatomy of the mediastinum and the exploration of new surgical approaches such as the RACE or MICE.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

[Robot-assisted vs laparoscopic gastric bypass : First experiences with the DaVinci system in bariatric surgery]

Conventional laparoscopy is the gold standard in bariatric surgery. Internationally, robot-assisted surgery is gaining in importance. Up to now there are only few reports from Germany on the use of the system in bariatric surgery. Since January 2017 we have been performing robot-assisted gastric bypass surgery. It remains unclear whether the use of the robotic system has advantages over the well-established laparoscopic technique. Within a period from January to early August 2017 a total of 53 gastric bypass operations were performed. Of these 16 proximal redo Roux-en-Y gastric bypass operations were performed with the DaVinci Si system versus 29 laparoscopic procedures. A retrospective analysis of the perioperative course was carried out. Body weight, body mass index (BMI), Edmonton obesity staging system (EOSS) and American Society of Anesthesiologists (ASA) classification did not show significant differences. There were also no significant differences in terms of estimated blood loss, intraoperative complications, duration of surgery, postoperative inflammatory parameters and weight loss. There was no mortality and no need for revisional surgery in either group. After laparoscopic surgery there was a delayed occurrence of a leak of the gastrojejunostomy followed by readmission and endoscopic negative pressure wound therapy. The results show that the proximal Roux-en-Y gastric bypass can be performed safely and efficiently using the DaVinci surgical system. Significant differences to the conventional laparoscopic procedure were not found. Larger randomized controlled trials are needed to define the role of the DaVinci system in bariatric surgery.

Risk evaluation in cutaneous melanoma patients undergoing lymph node dissection: impact of POSSUM

INTRODUCTION

When lymphatic metastasis occurs, surgery is the primary treatment modality in melanoma patients. Depending on the tumour stage, patients receive a completion lymph node dissection (CLND) when a positive sentinel node is detected. Patients with clinically evident disease of the regional lymph nodes are recommended to undergo a therapeutic lymph node dissection (TLND). The aim of this study was to assess the morbidity of CLND and TLND and to evaluate the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) for preoperative risk adjustment of postoperative morbidity.

METHODS

The hospital files of 143 patients who underwent CLND and TLND for malignant melanoma were analysed. The POSSUM score was used to predict morbidity rates after surgery for the total patient group as well as separated for CLND and TLND patients.

RESULTS

The overall complication rate was 28.0% and the mortality rate was 0%. The morbidity rate predicted by POSSUM was 32.9%, the mortality 8.3%. Morbidity in patients undergoing CLND was significantly higher with regard to overall wound complications compared with patients with TLND. In these subgroups, POSSUM failed to predict the rates precisely.

CONCLUSIONS

The POSSUM score predicted the morbidity of the total patient group accurately but failed to predict the rates in the TLND and CLND subgroups. Patients receiving CLND showed the highest morbidity rates. Preoperative sentinel lymph node biopsy therefore has more influence on postoperative morbidity than the physiological parameters represented in the POSSUM physiological score.

Audit of a series of 40 gastrointestinal stromal tumour cases

AIMS

To analyze prognostic factors influencing survival and tumour recurrence after resection of gastrointestinal stromal tumours.

METHODS

Forty patients who underwent surgery for a GIST at our institution were reviewed. Patients were classified on the basis of tumour size, mitotic rate and CD117 positivity. The overall survival and disease free survival were calculated using Kaplan-Meier method considering the extent of surgery comparing local tumour excisions with segmental organ resections.

RESULTS

Tumours were localized in the oesophagus, stomach, duodenum, small bowel and large bowel and rectum. Sixty-five percent of the patients had an intermediate or high risk GIST according to tumour size and mitotic count. In 26/40 patients tumour resection was performed using segmental organ resection, in all other patients local tumour excision was carried out. The mean overall survival was 73 months. Disease free survival was significantly better after local tumour excision compared to segmental organ resection (73 months versus 53 months; p=0.05). Large tumour size (p=0.07) and high mitotic count (p=0.14) were negative prognostic factors for disease free survival, although statistical significance was not reached yet.

CONCLUSION

Primary surgery remains the cornerstone in the treatment of primary and recurrent GIST. Risk adapted surgery is the most important factor to avoid early tumour recurrence. In case of small tumour size segmental organ resections can be avoided favouring local tumour excisions with a low risk of tumour recurrence.