Role of preoperative 3D rendering for minimally invasive parenchyma sparing liver resections.

BACKGROUND: 3D rendering (3DR) represents a promising approach to plan surgical strategies. The study aimed to compare the results of minimally invasive liver resections (MILS) in patients with 3DR versus conventional 2D CT-scan. METHODS: We performed 118 3DR for various indications; the patients underwent a preoperative tri-phasic CT-scan and rendered with Synapse3D® Software. Fifty-six patients undergoing MILS with pre-operative 3DR were compared to a similar cohort of 127 patients undergoing conventional pre-operative 2D CT-scan using the propensity score matching (PSM) analysis. RESULTS: The 3DR mandated pre-operative surgical plan variations in 33.9% cases, contraindicated surgery in 12.7%, providing a new surgical indication in 5.9% previously excluded cases. PSM identified 39 patients in both groups with comparable results in terms of conversion rates, blood loss, blood transfusions, parenchymal R1-margins, grade ≥3 Clavien-Dindo complications, 90-days mortality, and hospital stay respectively in 3DR and conventional 2D. Operative time was significantly increased in the 3DR group (402 vs. 347 min, p = 0.020). Vascular R1 resections were 25.6% vs 7.7% (p = 0.068), while the conversion rate was 0% vs 10.2% (p = 0.058), respectively, for 3DR group vs conventional 2D. CONCLUSION: 3DR may help in surgical planning increasing resectability rate while reducing conversion rates, allowing the precise identification of anatomical landmarks in minimally invasive parenchyma-preserving liver resections.

Effectiveness of an immersive virtual reality environment on curricular training for complex cognitive skills in liver surgery: a multicentric crossover randomized trial.

BACKGROUND: Virtual reality (VR) is increasingly used in surgical education, but evidence of its benefits in complex cognitive training compared to conventional 3-dimensional (3D) visualization methods is lacking. The objective of this study is to assess the impact of 3D liver models rendered visible by VR or desktop interfaces (DIs) on residents' performance in clinical decision-making. METHOD: From September 2020 to April 2021, a single-blinded, crossover randomized educational intervention trial was conducted at two university hospitals in Belgium and Italy. A proficiency-based stepwise curriculum for preoperative liver surgery planning was developed for general surgery residents. After completing the training, residents were randomized in one of two assessment sequences to evaluate ten real clinical scenarios. RESULTS: Among the 50 participants, 46 (23 juniors/23 seniors) completed the training and were randomized. Forty residents (86.96%) achieved proficiency in decision-making. The accuracy of virtual surgical planning using VR was higher than that using DI in both groups A (8.43 ± 1.03 vs 6.86 ± 1.79, p < 0.001) and B (8.08 ± 0.9 vs 6.52 ± 1.37, p < 0.001). CONCLUSION: Proficiency-based curricular training for liver surgery planning successfully resulted in the acquisition of complex cognitive skills. VR was superior to DI visualization of 3D models in decision-making. GOV ID: NCT04959630.

Systematic review, meta-analysis and single-centre experience of the diagnostic accuracy of intraoperative near-infrared indocyanine green-fluorescence in detecting pancreatic tumours.

BACKGROUND: During pancreatic resections assessing tumour boundaries and identifying the ideal resection margins can be challenging due to the associated pancreatic gland inflammation and texture. This is particularly true in the context of minimally invasive surgery, where there is a very limited or absent tactile feedback. Indocyanine green (ICG) fluorescence imaging can assist surgeons by simply providing valuable real-time intraoperative information at low cost with minimal side effects. This meta-analysis summarises the available evidence on the use of near-infrared fluorescence imaging with ICG for the intraoperative visualization of pancreatic tumours (PROSPERO ID: CRD42021247203). METHODS: MEDLINE, Embase, and Web Of Science electronic databases were searched to identify manuscripts where ICG was intravenously administered prior to or during pancreatic surgery and reporting the prevalence of pancreatic lesions visualised through fluorescence imaging. RESULTS: Six studies with 7 series' reporting data on 64 pancreatic lesions were included in the analysis. MINOR scores ranged from 6 to 10, with a median of 8. The most frequent indications were pancreatic adenocarcinoma and neuroendocrine tumours. In most cases (67.2%) ICG was administered during surgery. ICG fluorescence identified 48/64 lesions (75%) with 81.3% accuracy, 0.788 (95%CI 0.361-0.961) sensitivity, 1 (95%CI 0.072-1) specificity and positive predictive value of 0.982 (95%CI 0.532-1). In line with the literature, ICG fluorescence identified 5/6 (83.3%) of pancreatic lesions during robotic pancreatic resections performed at our Institution. CONCLUSION: This meta-analysis is the first summarising the results of ICG immunofluorescence in detecting pancreatic tumours during surgery, showing good accuracy. Additional research is needed to define optimal ICG administration strategies and fluorescence intensity cut-offs.

Robotic central pancreatectomy: a systematic review and meta-analysis.

BACKGROUND: Central pancreatectomy is usually performed to excise lesions of the neck or proximal body of the pancreas. In the last decade, thanks to the advent of novel technologies, surgeons have started to perform this procedure robotically. This review aims to appraise the results and outcomes of robotic central pancreatectomies (RCP) through a systematic review and meta-analysis. METHODS: A systematic search of MEDLINE, Embase, and Web Of Science identified studies reporting outcomes of RCP. Pooled prevalence rates of postoperative complications and mortality were computed using random-effect modelling. RESULTS: Thirteen series involving 265 patients were included. In all cases but one, RCP was performed to excise benign or low-grade tumours. Clinically relevant post-operative pancreatic fistula (POPF) occurred in 42.3% of patients. While overall complications were reported in 57.5% of patients, only 9.4% had a Clavien-Dindo score ≥ III. Re-operation was necessary in 0.7% of the patients. New-onset diabetes occurred postoperatively in 0.3% of patients and negligible mortality and open conversion rates were observed. CONCLUSION: RCP is safe and associated with low perioperative mortality and well preserved postoperative pancreatic function, although burdened by high overall morbidity and POPF rates.

Hepatic function assessment to predict post-hepatectomy liver failure: what can we trust? A systematic review.

Post hepatectomy liver failure (PHLF) could occur even though an adequate liver volume is preserved. Liver function is not strictly related to the volume and the necessity to pre-operatively predict the future liver remnant (FLR) function is emerging, together with the wide spreading of techniques, aiming to optimize the FLR. The aim of this study was to systematically review all the available tests, to pre-operatively assess the liver function and to estimate the risk of PHLF. A systematic literature research of Medline, Embase, Scopus was performed in accordance to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, to identify all the studies available for pre-operative liver function tests to assess the risk of PHLF and/or complications. From the 1122 references retrieved, 79 were included in the review. Dynamic functional tests, such as indocyanine green test (ICG), could evaluate only global liver function, with no definition of functional capacity of the remnant. Magnetic resonance imaging (MRI) with liver-specific contrast agents enables both liver function and volume evaluation; the absence of ionizing radiation showed a better patient's compliance. Nuclear imaging studies as hepatobiliary scintigraphy (HBS) present the unique ability to allow a precise evaluation of the segmental liver function of the remnant liver. Liver volume could overestimate liver function. Several liver function tests are available to evaluate the risk of PHLF in the pre-operative setting. However, no single test alone could accurately predict PHLF. Pre-operative combination between a dynamic quantitative test, such as ICG, with MRI or HBS, should enable a more complete functional evaluation. Functional tests to predict PHLF should be chosen according to patient's characteristics, disease, and center experience.

Post-operative morbidity following pancreatic duct occlusion without anastomosis after pancreaticoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: Pancreatic duct occlusion (PDO) without anastomosis is a technique proposed to mitigate the clinical consequences of postoperative pancreatic fistulas (POPF) after pancreaticoduodenectomy. The aim of this study was to appraise the morbidity following PDO through a systematic review and meta-analysis. METHODS: A systematic search of MEDLINE, Embase, and Web Of Science identified studies reporting outcomes of PDO following pancreaticoduodenectomy. Pooled prevalence rates of postoperative complications and mortality were computed using random-effect modeling. Meta-regression analyses were performed to examine the impact of moderators on the overall estimates. RESULTS: Sixteen studies involving 1000 patients were included. Pooled postoperative mortality was 2.7%. A POPF was reported in 29.7% of the patients. Clinically relevant POPFs occurred in 13.5% of the patients, while intra-abdominal abscess and haemorrhages occurred in 6.7% and 5.5% of the patients, respectively. Re-operation was necessary in 7.6% of the patients. Postoperatively new onset diabetes occurred in 15.8% of patients, more frequently after the use of chemical substances for PDO (p = 0.003). CONCLUSIONS: PDO is associated with significant morbidity including new onset of post-operative diabetes. The risk of new onset post-operative diabetes is associated with the use of chemical substance for PDO. Further evidence is needed to evaluate the potential benefits of PDO in patients at high risk of POPF.

Hepatobiliary scintigraphy and kinetic growth rate predict liver failure after ALPPS: a multi-institutional study.

BACKGROUND: Post hepatectomy liver failure (PHLF) after ALPPS has been related to the discrepancy between liver volume and function. Pre-operative hepatobiliary scintigraphy (HBS) can predict post-operative liver function and guide when it is safe to proceed with major hepatectomy. Aim of this study was to evaluate the role of HBS in predicting PHLF after ALPPS, defining a safe cut-off. METHODS: A multicenter retrospective study was approved by the ALPPS Registry. All patients selected for ALPPS between 2012 and 2018, were evaluated. Every patient underwent HBS during ALPPS evaluation. PHLF was reported according to ISGLS definition, considering grade B or C as clinically significant. RESULTS: 98 patients were included. Thirteen patients experienced PHLF grade B or C (14%) following ALPPS-2. The HBS and the daily gain in volume (KGRFLR) of the future liver remnant (FLR) were significantly lower in PHLF B and C (p = .004 and .041 respectively). ROC curves indicated safe cut-offs of 4.1%/day (AUC = 0.68) for KGRFLR, and of 2.7 %/min/m2 (AUC = 0.75) for HBSFLR. Multivariate analysis confirmed these cut-offs as variables predicting PHLF after ALPPS-2. CONCLUSION: Patients presenting a KGRFLR ≤4.1%/day and a HBSFLR ≤2.7%/min/m2 are at high risk of PHLF and their second stage should be re-discussed.

Hemodynamic changes in ALPPS influence liver regeneration and function: results from a prospective study.

BACKGROUND: Excessive increase of portal flow and pressure following extended hepatectomy have been associated to insufficient growth or function of the future liver remnant (FLR), with the risk of post-hepatectomy liver failure (PHLF). We prospectively assess the influence of liver hemodynamics on FLR regeneration and function in Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS). METHODS: Twenty-three patients underwent ALPPS; liver hemodynamics were assessed throughout the procedures. Volume and function of the FLR were evaluated by angio-CT and 99mTc-Mebrofenin-scintigraphy. RESULTS: The portal vein flow at the end of stage-1 correlated with the increase of the FLR volume (p = 0.002). Patients with portal vein pressure (PVP) < 20 mmHg and hepatic to portal vein gradients (HVPG) < 15 mmHg at the end of ALPPS-1 showed higher FLR regeneration (76.7% vs. 30.6%, p = 0.04) and function (26.7% vs. -0.13%, p = 0.02). FLR regeneration was inversely correlated with baseline FLR/Total Liver Volume (p = 0.002) and FLR/Body Weight (p = 0.02). No correlation was found between volumes and function (p = 0.13). CONCLUSION: Liver hemodynamic stress at the end of ALPPS-1 influences the increase of the FLR volume and function, which is higher with PVP < 20 and HVPG < 15 mmHg. Liver volume overestimates liver function and could be imprecise to set stage-2 timing.

Cap cuff-assisted colonoscopy versus standard colonoscopy for adenoma detection: a randomized back-to-back study.

BACKGROUND AND AIMS: EndoCuff is a disposable device applied to standard colonoscopes to improve mucosal visualization. Randomized parallel trials have shown that EndoCuff increases the adenoma detection rate (ADR). The primary aim of this study was to compare the ADR between EndoCuff-assisted colonoscopies (EAC) and standard colonoscopies within a randomized back-to-back trial. METHODS: This was a single-center randomized crossover study (NCT02374515) involving adult patients undergoing screening, surveillance, or diagnostic colonoscopy. Participants received back-to-back standard colonoscopies and EACs in a random order, performed by the same endoscopist. All polyps were excised, but only those proven at histology to be adenomas were considered for analysis. RESULTS: From February 2015 to March 2016, a total of 288 patients were enrolled, and 274 were included in the per-protocol analysis. Compared with standard colonoscopies, EACs increased the ADR (29.6% vs 26.3%; P < .01) and the number of diagnosed adenomas (176 vs 129; P < .01), particularly in the left (73 vs 46; P < .01) and right sides of the colon (83 vs 63; P < .01). EAC increased the detection of adenomas <5 mm (129 vs 84; P < .01), but no difference was found with regard to larger lesions. In 7.3% of patients, findings of EndoCuff shortened the surveillance interval determined by standard colonoscopy findings. EndoCuff caused 7 mucosal erosions (2.5% of patients), requiring a mucosal adrenaline injection in 1 case. CONCLUSIONS: The use of EndoCuff increases the number of identified adenomas, primarily small adenomas in the left and right sides of the colon. This increases the ADR and allows a better definition of the surveillance program. (Clinical trial registration number: NCT02374515.).

Confocal laser endomicroscopy in breast surgery: a pilot study.

BACKGROUND: Breast neoplasms include different histopathological entities, varying from benign tumors to highly aggressive cancers. Despite the key role of imaging, traditional histology is still required for a definitive diagnosis. Confocal Laser Endomicroscopy (CLE) is a new technique, which enables to obtain histopathological images in vivo, currently used in the diagnosis of gastrointestinal diseases. This is a single-center pilot feasibility study; the main aim is to describe the basic morphological patterns of Confocal Laser Endomicroscopy in normal breast tissue besides benign and malignant lesions. METHODS: Thirteen female patients (mean age 52.7, range from 22 to 86) who underwent surgical resection for a palpable breast nodule were enrolled. CLE was performed soon after resection with the Cellvizio® Endomicroscopy System (Mauna Kea Technologies, Paris, France), by using a Coloflex UHD-type probe; intravenous fluorescein was used as contrast-enhancing agent. The surgical specimen was cut along the main axis; dynamic images were obtained and recorded using a hand-held probe directly applied both to the internal part of the lesion and to several areas of surrounding normal tissue. Each specimen was then sent for definitive histologic examination. RESULTS: Histopathology revealed a benign lesion in six patients (46%), while a breast cancer was diagnosed in seven women (54%). Confocal laser endomicroscopy showed some peculiar morphological patterns. Normal breast tissue was characterized by a honeycomb appearance with regular, dark, round or hexagonal glandular lobules on a bright stroma background; tubular structures, representing ducts or blood vessels, were also visible in some frames. Benign lesions were characterized by a well-demarcated "slit-like" structure or by lobular structures in abundant bright stroma. Finally, breast cancer was characterized by a complete architectural subversion: ductal carcinoma was characterized by ill-defined structures, with dark borders and irregular ductal shape, formingribbons, tubules or nests; mucinous carcinoma showed smaller cells organized in clusters, floating in an amorphous extracellular matrix. CONCLUSIONS: This is the first pilot study to investigate the potential role of confocal laser imaging as a diagnostic tool in breast diseases. Further studies are required to validate these results and establish the clinical impact of this technique.