Retroperitoneum revisited: a review of radiological literature and updated concept of retroperitoneal fascial anatomy with imaging features and correlating anatomy.

PURPOSE: Spread of disease in the retroperitoneum is dictated by the complex anatomy of retroperitoneal fasciae and is still incompletely understood. Conflicting reports have led to insufficient and incorrect anatomical concepts in radiological literature. METHODS: This review will discuss previous concepts prevalent in radiological literature and their shortcomings will be highlighted. New insights from recent anatomical and embryological research, together with imaging examples, will be used to clarify patterns of disease spread in the retroperitoneum that remain unexplained by these concepts. RESULTS: The fusion fascia and the renal fascia in particular give rise to planes and spaces that act as vectors for spread of disease in the retroperitoneum. Some of these planes and structures, such as the caudal extension of the renal fascia, have previously not been described in radiological literature. CONCLUSION: New insights, including the various fasciae, potential spaces and planes, are incorporated into an updated combined retroperitoneal fascial concept.

Nationwide validation of the distal fistula risk score (D-FRS).

PURPOSE: Distal pancreatectomy (DP) is associated with a high complication rate of 30-50% with postoperative pancreatic fistula (POPF) as a dominant contributor. Adequate risk estimation for POPF enables surgeons to use a tailor-made approach. Assessment of the risk of POPF prior to DP can lead to the application of preventive strategies. The current study aims to validate the recently published preoperative and intraoperative distal fistula risk score (D-FRS) in a nationwide cohort. METHODS: This nationwide retrospective Dutch cohort study included all patients after DP for any indication, all of whom were registered in the Dutch Pancreatic Cancer Audit (DPCA) database between 2013 and 2021. The D-FRS was validated by filling in the probability equations with data from this cohort. The predictive capacity of the models was represented by an area under the receiver operating characteristic (AUROC) curve. RESULTS: A total of 896 patients underwent DP of which 152 (17%) developed POPF of whom 144 grade B (95%) and 8 grade C (5%). The preoperative D-FRS, consisting of the variables pancreatic neck thickness and pancreatic duct diameter, showed an AUROC of 0.73 (95%CI 0.68-0.78). The intraoperative D-FRS, comprising pancreatic neck, duct diameter, BMI, operating time, and soft pancreatic aspect, showed an AUROC of 0.69 (95%CI 0.64-0.74). CONCLUSION: The current study is the first nationwide validation of the preoperative and intraoperative D-FRS showing acceptable distinguishing capacity for only the preoperative D-FRS for POPF. Therefore, the preoperative score could improve prevention and mitigation strategies such as drain management, which is currently investigated in the multicenter PANDORINA trial.

Fluorescence-guided minimally-invasive resection of abdominal paragangliomas using indocyanine green.

This retrospective study explores the utility of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) in enhancing the intraoperative identification and guidance for the resection of abdominal paragangliomas. They can be challenging to detect during minimally invasive surgery, due to their anatomical location, varying size and similar appearance in regard to their surrounding tissue. Patients with suspected abdominal paragangliomas planned for a minimally-invasive resection were included. As part of standard of care they received single intravenous dose of 5 mg ICG after abdominal exploration. NIR fluorescence imaging of the anatomical region of the suspected lesion was performed immediately following intravenous administration, to assess fluorescence signals, intraoperative identification, and histopathological correlation. Out of five resected suspicious lesions, four were imaged with NIR fluorescence, pathology confirming four as paragangliomas, the latter turned out to be an adrenal adenoma. NIR fluorescence identified all four lesions, surpassing the limitations of white-light visualization. Homogeneous fluorescence signals appeared 30-60 s post-ICG administration, which lasted up to 30 min. The study demonstrates the feasibility and potential clinical value of fluorescence-guided minimally-invasive resections of abdominal paragangliomas using a single intravenous ICG dose. These findings support the scientific basis for routine use of ICG-fluorescence-guided surgery in challenging anatomical cases, providing valuable assistance in lesion detection and resection.

Consensus conference statement on fluorescence-guided surgery (FGS) ESSO course on fluorescence-guided surgery.

BACKGROUND: Fluorescence-guided surgery (FGS) has emerged as an innovative technique with promising applications in various surgical specialties. However, clinical implementation is hampered by limited availability of evidence-based reference work supporting the translation towards standard-of-care use in surgical practice. Therefore, we developed a consensus statement on current applications of FGS. METHODS: During an international FGS course, participants anonymously voted on 36 statements. Consensus was defined as agreement ≥70% with participation grade of ≥80%. All participants of the questionnaire were stratified for user and handling experience within five domains of applicability (lymphatics & lymph node imaging; tissue perfusion; biliary anatomy and urinary tracts; tumor imaging in colorectal, HPB, and endocrine surgery, and quantification and (tumor-) targeted imaging). Results were pooled to determine consensus for each statement within the respective sections based on the degree of agreement. RESULTS: In total 43/52 (81%) course participants were eligible as voting members for consensus, comprising the expert panel (n = 12) and trained users (n = 31). Consensus was achieved in 17 out of 36 (45%) statements with highest level of agreement for application of FGS in tissue perfusion and biliary/urinary tract visualization (71% and 67%, respectively) and lowest within the tumor imaging section (0%). CONCLUSIONS: FGS is currently established for tissue perfusion and vital structure imaging. Lymphatics & lymph node imaging in breast cancer and melanoma are evolving, and tumor tissue imaging holds promise in early-phase trials. Quantification and (tumor-)targeted imaging are advancing toward clinical validation. Additional research is needed for tumor imaging due to a lack of consensus.

Implementation and outcome of minimally invasive pancreatoduodenectomy in Europe: a registry-based retrospective study - a critical appraisal of the first 3 years of the E-MIPS registry.

BACKGROUND: International multicenter audit-based studies focusing on the outcome of minimally invasive pancreatoduodenectomy (MIPD) are lacking. The European Registry for Minimally Invasive Pancreatic Surgery (E-MIPS) is the E-AHPBA endorsed registry aimed to monitor and safeguard the introduction of MIPD in Europe. MATERIALS AND METHODS: A planned analysis of outcomes among consecutive patients after MIPD from 45 centers in 14 European countries in the E-MIPS registry (2019-2021). The main outcomes of interest were major morbidity (Clavien-Dindo grade ≥3) and 30-day/in-hospital mortality. RESULTS: Overall, 1336 patients after MIPD were included [835 robot-assisted (R-MIPD) and 501 laparoscopic MIPD (L-MIPD)]. Overall, 20 centers performed R-MIPD, 15 centers L-MIPD, and 10 centers both. Between 2019 and 2021, the rate of centers performing L-MIPD decreased from 46.9 to 25%, whereas for R-MIPD this increased from 46.9 to 65.6%. Overall, the rate of major morbidity was 41.2%, 30-day/in-hospital mortality 4.5%, conversion rate 9.7%, postoperative pancreatic fistula grade B/C 22.7%, and postpancreatectomy hemorrhage grade B/C 10.8%. Median length of hospital stay was 12 days (IQR 8-21). A lower rate of major morbidity, postoperative pancreatic fistula grade B/C, postpancreatectomy hemorrhage grade B/C, delayed gastric emptying grade B/C, percutaneous drainage, and readmission was found after L-MIPD. The number of centers meeting the Miami Guidelines volume cut-off of ≥20 MIPDs annually increased from 9 (28.1%) in 2019 to 12 (37.5%) in 2021 ( P =0.424). Rates of conversion (7.4 vs. 14.8% P <0.001) and reoperation (8.9 vs. 15.1% P <0.001) were lower in centers, which fulfilled the Miami volume cut-off. CONCLUSION: During the first 3 years of the pan-European E-MIPS registry, morbidity and mortality rates after MIPD were acceptable. A shift is ongoing from L-MIPD to R-MIPD. Variations in outcomes between the two minimally invasive approaches and the impact of the volume cut-off should be further evaluated over a longer time period.