Robotic and laparoscopic liver resection-comparative experiences at a high-volume German academic center

Purpose

Minimally invasive liver surgery (MILS) is a feasible and safe procedure for benign and malignant tumors. There has been an ongoing debate on whether conventional laparoscopic liver resection (LLR) or robotic liver resection (RLR) is superior and if one approach should be favored over the other. We started using LLR in 2010, and introduced RLR in 2013. In the present paper, we report on our experiences with these two techniques as early adopters in Germany.

Methods

The data of patients who underwent MILS between 2010 and 2020 were collected prospectively in the Magdeburg Registry for Minimally Invasive Liver Surgery (MD-MILS). A retrospective analysis was performed regarding patient demographics, tumor characteristics, and perioperative parameters.

Results

We identified 155 patients fulfilling the inclusion criteria. Of these, 111 (71.6%) underwent LLR and 44 (29.4%) received RLR. After excluding cystic lesions, 113 cases were used for the analysis of perioperative parameters. Resected specimens were significantly bigger in the RLR vs. the LLR group (405 g vs. 169 g, p = 0.002); in addition, the tumor diameter was significantly larger in the RLR vs. the LLR group (5.6 cm vs. 3.7 cm, p = 0.001). Hence, the amount of major liver resections (three or more segments) was significantly higher in the RLR vs. the LLR group (39.0% vs. 16.7%, p = 0.005). The mean operative time was significantly longer in the RLR vs. the LLR group (331 min vs. 181 min, p = 0.0001). The postoperative hospital stay was significantly longer in the RLR vs. the LLR group (13.4 vs. LLR 8.7 days, p = 0.03). The R0 resection rate for solid tumors was higher in the RLR vs. the LLR group but without statistical significance (93.8% vs. 87.9%, p = 0.48). The postoperative morbidity ≥ Clavien-Dindo grade 3 was 5.6% in the LLR vs. 17.1% in the RLR group (p = 0.1). No patient died in the RLR but two patients (2.8%) died in the LLR group, 30 and 90 days after surgery (p = 0.53).

Conclusion

Minimally invasive liver surgery is safe and feasible. Robotic and laparoscopic liver surgery shows similar and adequate perioperative oncological results for selected patients. RLR might be advantageous for more advanced and technically challenging procedures.

A falciform ligament flap surface sealing technique for laparoscopic and robotic-assisted liver surgery

Whether sealing the hepatic resection surface after liver surgery decreases morbidity is still unclear. Nevertheless, various methods and materials are currently in use for this procedure. Here, we describe our experience with a simple technique using a mobilized falciform ligament flap in minimally invasive liver surgery (MILS). We retrospectively analyzed the charts from 46 patients who received minor MILS between 2011 and 2019 from the same surgical team in a university hospital setting in Germany. Twenty-four patients underwent laparoscopic liver resection, and 22 patients received robotic-assisted liver resection. Sixteen patients in the laparoscopic group and fourteen in the robotic group received a falciform ligament flap (FLF) to cover the resection surface after liver surgery. Our cohort was thus divided into two groups: laparoscopic and robotic patients with (MILS + FLF) and without an FLF (MILS-FLF). Twenty-eight patients (60.9%) in our cohort were male. The overall mean age was 56.8 years (SD 16.8). The mean operating time was 249 min in the MILS + FLF group vs. 235 min in the MILS-FLF group (p = 0.682). The mean blood loss was 301 ml in the MILS + FLF group vs. 318 ml in the MILS-FLF group (p = 0.859). Overall morbidity was 3.3% in the MILS + FLF group vs. 18.8% in the MILS-FLF group (p = 0.114). One patient in the MILS-FLF group (overall 2.2%), who underwent robotic liver surgery, developed bile leakage, but this did not occur in the MILS + FLF group. Covering the resection surface of the liver after minor minimally invasive liver resection with an FLF is a simple and cost-effective technique that does not prolong surgical time or negatively affect other perioperative parameters. In fact, it is a safe add-on step during MILS that may reduce postoperative morbidity. Further studies with larger cohorts will be needed to substantiate our proof of concept and results.

A systematic model improves hepatitis C virus birth cohort screening in hospital-based primary care

Despite national and local governing board recommendations in the United States of America to perform an HCV screening test in baby boomers, screening rates remain low. Our goal was to study the impact of an HCV screening and link-to-care programme with patient navigation in two New York City primary care practices. This was a 2-year prospective study of patients born between 1945-1965 ("baby boomers") with encounters at two primary care practices at the Mount Sinai Hospital between November 1, 2013 and November 30, 2015. Baseline HCV screening rates were collected for four months. A multifaceted intervention was sequentially implemented involving electronic alerts, housestaff education, data feedback and patient navigation. HCV screening rates and link to care, defined as attending an appointment with a viral hepatitis specialist, were compared before and after these interventions. There were 14 642 primary care baby boomer patients of which 4419 (30.2%) were newly screened during the study. There was a significant increase in HCV screening rates from 55% to 75% (P<.01) with an HCV seropositive rate of 3.3%. Factors associated with being HCV seropositive included older age (P<.01), male sex (P<.01), African American race (P<.01) and receiving care in the housestaff practice (P<.01). With patient navigation, 78 of 84 (93%) newly diagnosed HCV-infected persons were referred to a specialist and 60 (77%) attended their first appointment. A structured, multifaceted HCV screening programme using well-studied principles identifies a large number of undiagnosed baby boomers within hospital-based primary care and improves access to specialty providers in a timely manner.

[Management of perioperative complications following tumor resection in the upper gastrointestinal tract]

BACKGROUND

Surgical resection of tumors of the upper gastrointestinal (GI) tract represent complex procedures and are still associated with a relevant morbidity and mortality. A targeted preoperative risk analysis and patient selection with consideration of the nutritional status and comorbidities are important in order to reduce the perioperative complication rate.

RESULTS AND DISCUSSION

Anastomotic leaks still remain the most feared surgical complication and in addition to early recognition, immediate initiation of an appropriate therapy are essential. Conservative treatment can be considered for small and adequately drained fistulas as well as in cervical leakages. Indications for surgical reintervention are leaks that occur in the early postoperative course, fulminant defects with diffuse mediastinitis and conduit necrosis. The majority of anastomotic leaks can be successfully managed with minimally invasive endoscopic techniques, e.g. stent placement and endoluminal vacuum therapy. Delayed gastric emptying is frequently observed following esophageal resection and usually shows a satisfactory response to medicinal treatment and endoscopic interventions. The benefits of pyloroplasty in the primary intervention is still a matter of debate. Chylothorax is a rare but serious complication which should initially be managed with conservative measures.

CONCLUSIONS

For the successful management of postoperative complications following surgical resection of tumors of the upper GI tract both an interdisciplinary approach and the availability of an appropriate infrastructure with defined algorithms are of paramount importance. Therefore, a concentration of these procedures in specialized centers would be highly desirable.

[Papillary tumors - therapeutic concepts]

Papillary tumors originate from the various structures of the ampulla of Vater; therefore, these rare tumors represent a heterogeneous group of tumor entities. Intestinal differentiated adenomas are the most common benign lesions, whereas intestinal differentiated papillary carcinomas are the most common malignant tumors. Carcinomas with pancreaticobiliary differentiation have a poorer prognosis. Mesenchymal and neuroendocrine tumors are among the least frequent papillary tumors. Diagnosis is performed by side-view upper endoscopy and biopsy. In cases of suspected malignancy a complete staging with computed tomography (CT) and endoscopic ultrasound scanning is indicated to determine local tumor spread.Adenomas are removed by endoscopic snare papillectomy whereas the therapy of choice for papillary carcinomas is pancreatic head resection with systematic lymphadenectomy. Patients with papillary carcinomas are most likely to benefit from adjuvant therapy, which should be determined in an interdisciplinary consensus conference considering the histological differentiation of the tumor.

[Arterial and portal venous complications after HPB surgical procedures: Interdisciplinary management]

The surgical treatment of hepatopancreatobiliary (HPB) diseases requires complex operative procedures. Within the last decades the morbidity (36-50 %) and mortality (<5 %) of these procedures could be reduced; nonetheless, postoperative complications still occur in 41.2 % of cases. Compared with hepatobiliary procedures, pancreatic surgery shows an increased rate of complications. Postoperative bleeding has a major effect on the outcome and the incidence is 6.7 % after pancreatic surgery and 3.2 % after hepatobiliary surgery. The major causes of early postoperative hemorrhage are related to technical difficulties in surgery whereas late onset postoperative hemorrhage is linked to anastomosis insufficiency, formation of fistulae or abscesses due to vascular arrosion or formation of pseudoaneurysms. In many cases, delayed hemorrhage is preceded by a self-limiting sentinel bleeding. The treatment is dependent on the point in time, location and severity of the hemorrhage. The majority of early postoperative hemorrhages require surgical treatment. Late onset hemorrhage in hemodynamically stable patients is preferably treated by radiological interventions. After interventional hemostatic therapy 8.2 % of patients require secondary procedures. In the case of hemodynamic instability or development of sepsis, a relaparotomy is necessary. The treatment concept includes surgical or interventional remediation of the underlying cause of the hemorrhage. Other causes of postoperative morbidity and mortality are arterial and portal venous stenosis and thrombosis. Following liver resection, thrombosis of the portal vein occurs in 8.5-9.1 % and in 11.6 % following pancreatic resection with vascular involvement. Interventional surgical procedures or conservative treatment are suitable therapeutic options depending on the time of diagnosis and clinical symptoms. The risk of morbidity and mortality after HPB surgery can be reduced only in close interdisciplinary cooperation, which is particularly true for vascular complications.

Inhibition of tumor angiogenesis by antibodies, synthetic small molecules and natural products

Cancer remains one of the major causes of death worldwide. The switch to pathological angiogenesis is a key process in the promotion of cancer and consequently provides several new and promising targets to anticancer therapy. Thus, antagonizing angiogenesis cuts off the tumor's oxygen and nutrition supply. This review focuses on angiogenesis inhibitors as option for cancer treatment. Modes of action, adverse effects, mechanisms of resistance as well as new developments are highlighted. One approach in angiogenesis inhibition is intermitting the further VEGF (vascular endothelial growth factor) signal pathway with monoclonal antibodies. Bevacizumab is a highly specific recombinant humanized monoclonal IgG antibody targeting VEGF-A. An efficient antitumor therapy demands more specific antibodies that affect other signal molecules besides VEGF-A, which is in the focus of current research. In addition to antagonizing VEGF, there are also small molecules that inhibit receptor tyrosine kinases (RTKs). Many RTK inhibitors have been described, which exhibit different specificity profiles. The question, whether highly specific antagonists are necessary remains open, because other affected RTKs may also represent growth factor receptors that are essential for tumor growth. Therefore their inhibition may also contribute to anticancer activity. Secondary plant metabolites represent templates for the development of new small molecules. The identification of new drugs from plants has a long and successful history. There is convincing evidence for the beneficial effect of phytochemicals on cancer-related pathways, particularly with regard to anti-angiogenesis. Plant phenolics are the most important category of phytochemicals, including flavanoids. Prominent phytochemicals affecting different pathways of angiogenesis are green tea polyphenols (epigallocatechin gallate) and soy bean isoflavones (genistein).

[Revision after failed bariatric surgery--review of complications and current therapeutic options]

BACKGROUND

Obesity is increasing worldwide at an alarming rate. Particularly in Western countries, obesity and related problems have become a serious medical problem and an enormous socio-economic burden.

DISCUSSION

Currently, surgery is the only avail-able treatment for patients with severe obesity which leads to sustained weight loss and cure of co-morbidities in the majority of the patients. The increase in the number of bariatric operations and the occasional failure and complications of these surgical procedures have resulted in an increased need for revision surgery. Overall, 10-25 % of patients are expected to need a revision for failure of the primary bariatric procedure. The main indications for revision procedures are inadequate weight loss, surgery-related complications as well as surgical emergencies and long-term complications caused by malnutrition or -vitamin deficiencies. Unfortunately, there are currently no randomised trials to answer the question as to which operation should be performed in which patient and after which procedure. Decisions are often influenced by the expertise and preference of the operating surgeon as well as by patient's preference. Thus, a systematic review of published data to this complex issue appears to be helpful and important for daily surgical practise.

CONCLUSIONS

Revision bariatric procedures are technically more complex and associated with increased postoperative complications. These operations should basically be performed in centres with profound expertise in this field of surgery, and - whenever possible - laparoscopically. However, every abdominal surgeon should be able to diagnose and treat some acute complications. After failed restrictive procedures, revision is recommended only in cases of complications but with adequate weight loss at the time of failure. Otherwise, conversion to combined procedures should be considered. After the failure of combined procedures, further weight loss or successful treatment of complications can be achieved by adding more restriction and/or malabsorption components. The latter is associated with an increased risk of nutritional sequelae.

Utilizing genetically engineered bacteria to produce plant-specific glucosides

Plant-derived glucosides have attracted much attention due to their widespread applications. This class of products is difficult to isolate or to synthesize in pure form because of the resulting low yields. Thus, simple approaches for the generation of such glucosides would be highly beneficial. We purified and characterized a novel glucosyltransferase from plant cell suspension cultures of Rauvolfia serpentina, which showed rather low substrate specificity. We obtained its cDNA and expressed the active recombinant protein in bacteria (Escherichia coli) with excellent plant-specific glucosylation efficiencies. Compared with the plant system, the bacteria delivered the new enzyme, which was in the form of a soluble or matrix-bound enzyme, approximately 1800 times more efficiently for the synthesis of a wide range of glucosides. More importantly, the engineered E. coli strain allowed for in vivo glucosylation and release of the product into the culture medium, as shown by the formation of arbutin, which is a potent inhibitor of human melanin biosynthesis with commercial value.

Hydroquinone: O-glucosyltransferase from cultivated Rauvolfia cells: enrichment and partial amino acid sequences

Plant cell suspension cultures of Rauvolfia are able to produce a high amount of arbutin by glucosylation of exogenously added hydroquinone. A four step purification procedure using anion exchange, hydrophobic interaction, hydroxyapatite-chromatography and chromatofocusing delivered in a yield of 0.5%, an approximately 390 fold enrichment of the involved glucosyltransferase. SDS-PAGE showed a M(r) for the enzyme of 52 kDa. Proteolysis of the pure enzyme with endoproteinase LysC revealed six peptide fragments with 9-23 amino acids which were sequenced. Sequence alignment of the six peptides showed high homologies to glycosyltransferases from other higher plants.