Laparoscopic surgery of liver tumors

Preoperative and intraoperative laparoscopic liver surface registration using deep graph matching of representative overlapping points

PURPOSE

In laparoscopic liver surgery, registering preoperative CT-extracted 3D models with intraoperative laparoscopic video reconstructions of the liver surface can help surgeons predict critical liver anatomy. However, the registration process is challenged by non-rigid deformation of the organ due to intraoperative pneumoperitoneum pressure, partial visibility of the liver surface, and surface reconstruction noise.

METHODS

First, we learn point-by-point descriptors and encode location information to alleviate the limitations of descriptors in location perception. In addition, we introduce a GeoTransformer to enhance the geometry perception to cope with the problem of inconspicuous liver surface features. Finally, we construct a deep graph matching module to optimize the descriptors and learn overlap masks to robustly estimate the transformation parameters based on representative overlap points.

RESULTS

Evaluation of our method with comparative methods on both simulated and real datasets shows that our method achieves state-of-the-art results, realizing the lowest surface registration error(SRE) 4.12 mm with the highest inlier ratios (IR) 53.31% and match scores (MS) 28.17%.

CONCLUSION

Highly accurate and robust initialized registration obtained from partial information can be achieved while meeting the speed requirement. Non-rigid registration can further enhance the accuracy of the registration process on this basis.

Intraoperative laparoscopic liver surface registration with preoperative CT using mixing features and overlapping region masks

PURPOSE

Laparoscopic liver resection is a minimal invasive surgery. Augmented reality can map preoperative anatomy information extracted from computed tomography to the intraoperative liver surface reconstructed from stereo 3D laparoscopy. However, liver surface registration is particularly challenging as the intraoperative surface is only partially visible and suffers from large liver deformations due to pneumoperitoneum. This study proposes a deep learning-based robust point cloud registration network.

METHODS

This study proposed a low overlap liver surface registration algorithm combining local mixed features and global features of point clouds. A learned overlap mask is used to filter the non-overlapping region of the point cloud, and a network is used to predict the overlapping region threshold to regulate the training process.

RESULTS

We validated the algorithm on the DePoLL (the Deformable Porcine Laparoscopic Liver) dataset. Compared with the baseline method and other state-of-the-art registration methods, our method achieves minimum target registration error (TRE) of 19.9 ± 2.7 mm.

CONCLUSION

The proposed point cloud registration method uses the learned overlapping mask to filter the non-overlapping areas in the point cloud, then the extracted overlapping area point cloud is registered according to the mixed features and global features, and this method is robust and efficient in low-overlap liver surface registration.

Clinical efficacy of laparoscopic radical hepatectomy and laparotomy for hepatocellular carcinoma and factors of postoperative recurrence

Objective

For exploring the clinical efficacy of laparoscopic radical hepatectomy and laparotomy for hepatocellular carcinoma and analysing related factors of postoperative recurrence.

Methods

Totally 212 patients with hepatocellular carcinoma admitted to our hospital between April 2017 and December 2020 were enrolled, and all of them were followed up after the operation. According to the treatment modes, the patients were assigned to a laparotomy group (n=106) and a laparoscopic group (n=106). Perioperative indicators, haematological examination results, complications and recurrence were compared between the two groups. The recurrence time of hepatocellular carcinoma after the operation was confirmed by imaging examination with definite mass, and logistic multivariate analysis was used for analyzing the risk factors associated with postoperative recurrence.

Results

Patients in both groups were comparable in terms of general baseline data. The laparoscopic group experienced longer operation time and shorter incision length, less intraoperative blood loss, early time to have the first off-bed activity and time to eat liquid and shorter hospital stay than the laparotomy group (all P<0.05). Seven days after the operation, the laparoscopic group showed notably lower levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), tumour necrosis factor-α (TNF-α), interleukin-8 (IL-8), and C-reactive protein (CRP) than the laparotomy group (all P<0.05), and also showed notably higher levels of immunoglobulin A (IgA), IgG and IgM than the laparotomy group (all P<0.05). Additionally, the laparotomy group showed a higher total incidence rate of complications than the laparoscopic group (19.81% vs. 9.43%, P<0.05). During the one-year follow-up, the laparotomy group was not greatly different from the laparoscopic group in recurrence rate (22.64% (24/106) vs. 16.98% (18/106), P>0.05). Multivariate analysis showed that average tumour diameter and microvascular invasion were risk factors for postoperative recurrence (P<0.05).

Conclusion

Laparoscopic radical hepatectomy for hepatocellular carcinoma can reduce the influence on liver function and immune function, with less damage to tissues, and can ameliorate postoperative inflammatory reaction, and promote postoperative recovery of patients as soon as possible. There are many factors influencing the postoperative recurrence of hepatocellular carcinoma, and average tumour diameter and microvascular invasion are the risk factors.

OUP accepted manuscript

Background

Laparoscopic liver resection (LLR) is a highly demanding procedure with great variability. Previously published randomized trials have proven oncological safety of laparoscopic liver resection (LLR) as compared to open surgery. However, these were started after the learning curve (LC) was established. This leaves the question of whether the LC of LLR in the early laparoscopic era has affected the survival of patients with colorectal liver metastasis (CRLM).

Methods

All consecutive LLRs performed by a single surgeon between 2000 and 2019 were retrospectively analysed. A risk-adjusted cumulative sum (RA-CUSUM) chart for conversion rate and the log regression analysis of the blood loss identified two phases in the LC. This was then applied to patients with CRLM, and the two subgroups were compared for recurrence-free (RFS) and overall survival (OS). The analysis was repeated with propensity score-matched (PSM) groups

Results

A total of 286 patients were included in the LC analysis, which identified two distinct phases, the early (EP; 68 patients) and the late (LP; 218 patients) phases. The LC was applied to 192 patients with colorectal liver metastasis (EPc, 45 patients; LPc, 147 patients). For patients with CRLM, R0 resection was achieved in 93 per cent: 100 per cent in the EPc group and 90 per cent in the LPc group (P = 0.026). Median OS and RFS were 60 and 16 months, respectively. The 5-year OS and RFS were 51 per cent and 32.7 per cent, respectively. OS (hazard ratio (h.r.) 0.78, 95 per cent confidence interval (c.i.) 0.51 to 1.2; P = 0.286) and RFS (h.r. 0.94, 95 per cent c.i. 0.64 to 1.37; P = 0.760) were not compromised by the learning curve. The results were replicated after PSM.

Conclusion

In our experience, the development of a laparoscopic liver resection programme can be achieved without adverse effects on the long-term survival of patients with CRLM.

Performance of image guided navigation in laparoscopic liver surgery - A systematic review

BACKGROUND

Compared to open surgery, minimally invasive liver resection has improved short term outcomes. It is however technically more challenging. Navigated image guidance systems (IGS) are being developed to overcome these challenges. The aim of this systematic review is to provide an overview of their current capabilities and limitations.

METHODS

Medline, Embase and Cochrane databases were searched using free text terms and corresponding controlled vocabulary. Titles and abstracts of retrieved articles were screened for inclusion criteria. Due to the heterogeneity of the retrieved data it was not possible to conduct a meta-analysis. Therefore results are presented in tabulated and narrative format.

RESULTS

Out of 2015 articles, 17 pre-clinical and 33 clinical papers met inclusion criteria. Data from 24 articles that reported on accuracy indicates that in recent years navigation accuracy has been in the range of 8-15 mm. Due to discrepancies in evaluation methods it is difficult to compare accuracy metrics between different systems. Surgeon feedback suggests that current state of the art IGS may be useful as a supplementary navigation tool, especially in small liver lesions that are difficult to locate. They are however not able to reliably localise all relevant anatomical structures. Only one article investigated IGS impact on clinical outcomes.

CONCLUSIONS

Further improvements in navigation accuracy are needed to enable reliable visualisation of tumour margins with the precision required for oncological resections. To enhance comparability between different IGS it is crucial to find a consensus on the assessment of navigation accuracy as a minimum reporting standard.

Hand-assisted Laparoscopic Surgery for Colorectal Liver Metastasis: Analysis of Short-term and Long-term Results

BACKGROUND

There is scant data regarding the outcomes of hand-assisted laparoscopic surgery (HALS) for colorectal liver metastasis (CRLM). The aim of this study is to report our experience and analyze the short-term and long-term results.

MATERIALS AND METHODS

Retrospective study of patients undergoing HALS for CRLM in 2 university affiliated medical centers.

RESULTS

Two hundred and thirty-eight liver procedures were performed on 145 patients including 205 parenchymal sparing resections and 33 anatomic resections. The median number of metastases was 1 (range: 1 to 8), 38 patients (26.2%) had 3 or more metastases, and 41 patients (28.3 had a bi-lobar disease. The tumor size was 20 (2 to 90) mm, and 52 patients (36.6%) had a tumor larger than 30 mm. Nighty-nine patients (67.8%) received neoadjuvant chemotherapy. In 8 patients (5.5%) the laparoscopic liver resection was combined with ablation, and 16 patients (11%) underwent a synchronous resection of colorectal cancer. The median operative time, blood loss during surgery, and postoperative hospital stay were 163 minutes, 300 mL, and 4 days, respectively. The median modified Iwate complexity score was 4 (0 to 10) and the conversion rate to open surgery was 5.5%. The overall and major complication rates were 23.8% and 3.6%, respectively. The mortality rate was 0.7%. R0 resections were achieved in 91% of patients. Median overall survival for all the cohort (intend to treat) was 59 months, and the 8- and 10-year overall survival rates were 47.3% and 24.9%, respectively.

CONCLUSIONS

This study shows that HALS is a safe and efficacious treatment for selected patients with CRLM.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

Efficacy of the Novel Medical Adhesive, MAR-VIVO-107, in an Acute Porcine Liver Resection Model

BACKGROUND

Despite modern surgical techniques, insufficient hemostasis after liver trauma is still a major cause of morbidity and mortality after injury. Therefore, efficient hemostatic agents are indicated. In this study, we evaluated the hemostatic efficacy of a novel synthetic wound adhesive (MAR-VIVO-107) based on polyurethane/polyurea, compared with a widely used fibrin adhesive (Tisseel).

MATERIALS AND METHODS

Twelve German Landrace pigs were randomly assigned to 2 groups. The animals were operated under sterile conditions. A midline laparotomy was performed and the left liver lobe was isolated and resected, using a surgical scissor, in order to induce hepatic trauma. MAR-VIVO-107 or Tisseel was applied to the resected area. The animals were monitored for 60 minutes; thereafter, they were sacrificed under anesthesia. Blood and tissue samples were collected pre- and postresection for biochemical and hematological analyses.

RESULTS

MAR-VIVO-107 versus Tisseel (mean ± SD, P value)-postsurgical survival rate was 100% in both groups. Bleeding time was significantly higher in Tisseel compared with MAR-VIVO-107 (10.3 ± 5.0 vs 3.7 ± 1.5 minutes, P = .0124). In trend, blood loss was less in the MAR-VIVO-107 group (54.3 ± 34.9 vs 105.5 ± 65.8 g, P = .222). Aspartate transaminase levels were significantly lower in the MAR-VIVO-107 group when compared with the Tisseel group (39.0 ± 10.0 vs 72.4 ± 23.4 U/L, P = .0459).

CONCLUSION

The efficacy of MAR-VIVO-107 and comparable performance to the gold standard fibrin have been shown under pre-clinical conditions. MAR-VIVO-107 permits hemorrhage control within seconds, even in wet environment.

[Management of bleeding and infections in the context of visceral surgery]

Bleeding and vascular infections are serious potential complications during abdominal general surgery. The management of bleeding depends on the extent and localization and can range from the application of hemostatics to vascular sutures, interpositioning and ligatures. The use of prosthetic biomaterials implanted endoluminally or during open reconstruction permits palliation of potentially fatal conditions. The overall incidence of infections involving vascular prostheses is relatively low because of routine antibiotic prophylaxis prior to surgery, refinements in sterilization and packaging of devices and careful adherence to aseptic procedural and surgical techniques. When infections occur detection and definitive therapy of the vascular prosthesis are often delayed and the management is complex and tedious. Infections involving vascular prostheses are difficult to eradicate and in general, surgical therapy is required often coupled with excision of the prosthesis. Keys to success include accurate diagnostics to identify the organism and extent of graft infections, specific long-term antibiotic therapy and well-planned surgical interventions to excise and replace the infected graft and sterilize the local tissue. Regardless of the technique used to eradicate graft infections, success is measured by patient survival, freedom from recurrent infection and patency of revascularization. Even when treatment is successful, the morbidity associated with vascular graft infections is considerable. Aortoenteric fistulas (AEF) are a rare (incidence < 1.5 %) but often fatal complication. Primary diagnosis of AEF remains difficult. Computed tomography (CT) and fluorodeoxyglucose positron emission tomography CT (FDG-PET-CT) are the diagnostic tools of choice. Therapy consists of an urgent individualized interdisciplinary surgical approach with primary axillofemoral bypass and secondary prosthesis explantation or in situ replacement and subsequent bowel resection. Endovascular aortic repair (EVAR) is reserved for primary aortoenteric fistulas in patients with no signs of infection or in emergency cases as a bridging method.

Totally laparoscopic liver resection: new Brazilian experience

Background

Despite the increasing number of laparoscopic hepatectomy, there is little published experience.

Aim

To evaluate the results of a series of hepatectomy completely done with laparoscopic approach.

Methods

This is a retrospective study of 61 laparoscopic liver resections. Were studied conversion to open technique; mean age; gender, mortality; complications; type of hepatectomy; surgical techniques applied; and simultaneous operations.

Results

The conversion to open technique was necessary in one case (1.6%). The mean age was 54.7 years (17-84), 34 were men. Three patients (4.9%) had complications. One died postoperatively (mortality 1.6%) and no deaths occurred intraoperatively. The most frequent type was right hepatectomy (37.7%), followed by bisegmentectomy (segments II-III and VI-VII). Were not used hemi-Pringle maneuvers or assisted technic. Six patients (8.1%) underwent simultaneous procedures (hepatectomy and colectomy).

Conclusion

Laparoscopic hepatectomy is feasible procedure and can be considered the gold standard for various conditions requiring liver resections for both benign to malignant diseases.

[Minimally invasive surgery of primary and secondary liver tumors : indications, techniques and results]

BACKGROUND

Initially, mainly superficial liver lesions were resected laparoscopically but now even major resections are performed using a minimally invasive procedure. Careful selection of suitable patients is of key importance.

AIMS AND METHODS

This article describes the current state of the art in patient selection and choice of the appropriate laparoscopic technique based on a review of the recent literature. Perioperative and oncological outcome parameters of laparoscopic liver resection are presented.

RESULTS

Laparoscopic liver resection offers significant benefits compared to open liver resection in terms of reduced intraoperative blood loss, reduced overall and liver-specific complications and length of hospital stay without compromising oncological outcomes.

CONCLUSION

Lesions in the peripheral anterolateral segments (segments 2, 3, 4b, 5 and 6) are particularly suitable for laparoscopic liver resection. Access to the posterosuperior segments 1, 4a, 7 and 8 is more challenging but safe and feasible in experienced centers.

Explanted diseased livers - a possible source of metabolic competent primary human hepatocytes

Being an integral part of basic, translational and clinical research, the demand for primary human hepatocytes (PHH) is continuously growing while the availability of tissue resection material for the isolation of metabolically competent PHH remains limited. To overcome current shortcomings, this study evaluated the use of explanted diseased organs from liver transplantation patients as a potential source of PHH. Therefore, PHH were isolated from resected surgical specimens (Rx-group; n = 60) and explanted diseased livers obtained from graft recipients with low labMELD-score (Ex-group; n = 5). Using established protocols PHH were subsequently cultured for a period of 7 days. The viability and metabolic competence of cultured PHH was assessed by the following parameters: morphology and cell count (CyQuant assay), albumin synthesis, urea production, AST-leakage, and phase I and II metabolism. Both groups were compared in terms of cell yield and metabolic function, and results were correlated with clinical parameters of tissue donors. Notably, cellular yields and viabilities were comparable between the Rx- and Ex-group and were 5.3±0.5 and 2.9±0.7×10⁶ cells/g liver tissue with 84.3±1.3 and 76.0±8.6% viability, respectively. Moreover, PHH isolated from the Rx- or Ex-group did not differ in regards to loss of cell number in culture, albumin synthesis, urea production, AST-leakage, and phase I and II metabolism (measured by the 7-ethoxycoumarin-O-deethylase and uracil-5′-diphosphate-glucuronyltransferase activity). Likewise, basal transcript expressions of the CYP monooxygenases 1A1, 2C8 and 3A4 were comparable as was their induction when treated with a cocktail that consisted of 3-methylcholantren, rifampicin and phenobarbital, with increased expression of CYP 1A1 and 3A4 mRNA while transcript expression of CYP 2C8 was only marginally changed. In conclusion, the use of explanted diseased livers obtained from recipients with low labMELD-score might represent a valuable source of metabolically competent PHH which are comparable in viability and function to cells obtained from specimens following partial liver resection.

Laparoscopic resection for hepatocellular carcinoma: comparison between Middle Eastern and Western experience

BACKGROUND

Laparoscopic liver resection (LLR) is growing in popularity, but the short- and long-term outcome of patients undergoing LLR for hepatocellular carcinoma (HCC) has not yet been established.

METHODS

A literature search was performed using PubMed, Scopus, and Web of Science (WoS) from cited English and Chinese publications. Clinical and survival parameters were extracted. The search was last conducted in October 2013. After application of selective criteria, 24 remaining original studies with more than 15 patients were analyzed.

RESULTS

In the Western experience, mean operative time was between 150 to 300 minutes, and mean blood loss ranged from 55 to 452 mL. Transfusion was required in all series, ranging from 2.8% to 50%. The conversion rate ranged from 5% to 19.4%. Three cases of death were reported. General morbidity rate ranged from 1.5% to 25%. Specific complications were divided into hemorrhage (2.4% to 25%), ascites (3.7% to 15.3%), and biliary collection (0.6% to 5%). Liver insufficiency was reported in two cases. Mean hospital stay ranged from 5.4 to 15 days. In all case-matched studies, LLR was statistically associated with a shorter hospital stay. The 5-year overall survival rate ranged from 55% to 70%. No trocar-site recurrence was observed. The recurrence rate ranged from 21.4% to 50%. Comparative studies did not demonstrate any significant difference in terms of recurrence between LLR and open liver resection (OLR). In the Middle Eastern experience, mean operative time ranged from 147 to 325 minutes, and mean blood loss ranged from 88 to 808 mL. Transfusion was required, ranging from 1.8% to 19.2%. The conversion rate ranged from 1.8% to 18.6%, and four series reported no conversion. There was no mortality. The main specific complication was ascites (1.7% to 26.6%). A biliary collection was reported in only two series (10.7% and 13.3%), and only one case of postoperative liver insufficiency was reported. Mean hospital stay ranged from 4 to 11.5 days. Statistically, three comparative studies reported a shorter postoperative hospital stay following LLR versus OLR. The 5-year overall survival rate ranged from 50% to 76.6%. Comparative studies did not demonstrate any significant difference in terms of overall survival and recurrence rate between LLR and OLR. No trocar-site recurrence was reported. The recurrence rate ranged from 26.9% to 45.5%, and two series reported no recurrence.

CONCLUSIONS

Laparoscopic surgery should be considered an acceptable alternative for the treatment of HCC.