Quantification of Indocyanine Green Fluorescence Imaging in General, Visceral and Transplant Surgery

Near-infrared (NIR) imaging with indocyanine green (ICG) has proven to be useful in general, visceral, and transplant surgery. However, most studies have performed only qualitative assessments. Therefore, a systematic overview of all studies performing quantitative indocyanine green evaluation in general, visceral, and transplant surgeries should be conducted. Free term and medical subject heading (MeSH) term searches were performed in the Medline and Cochrane databases until October 2022. The main categories of ICG quantification were esophageal surgery (24.6%), reconstructive surgery (24.6%), and colorectal surgery (21.3%). Concordantly, anastomotic leak (41%) was the main endpoint, followed by the assessment of flap perfusion (23%) and the identification of structures and organs (14.8%). Most studies examined open surgery (67.6%) or laparoscopic surgery (23.1%). The analysis was mainly carried out using manufacturer software (44.3%) and open-source software (15.6%). The most frequently analyzed parameter was intensity over time for blood flow assessment, followed by intensity alone or intensity-to-background ratios for structure and organ identification. Intraoperative ICG quantification could become more important with the increasing impact of robotic surgery and machine learning algorithms for image and video analysis.

Robotic Liver Surgery - Current Standards and Future Perspectives

BACKGROUND

 Robotic liver surgery is emerging as the future of minimal invasive surgery. The robotic surgical system offers a stable camera platform, elimination of physiologic tremor, augmented surgical dexterity as well as improved ergonomics because of a seated operating position. Due to the theoretical advantages of the robotic assisted system, complex liver surgery might be an especially interesting indication for a robotic approach since it demands delicate tissue dissection, precise intracorporeal suturing as well as difficult parenchymal transection with subsequent need for meticulous hemostasis and biliostasis.

MATERIAL AND METHODS

 An analysis of English and German literature on open, laparoscopic and robotic liver surgery was performed and this review provides a general overview of the existing literature along with current standards and aims to specifically point out future directions of robotic liver surgery.

RESULTS

 Robotic liver surgery is safe and feasible compared to open and laparoscopic surgery, with improved short-term postoperative outcomes and at least non-inferior oncological outcomes.

CONCLUSION

 In complex cases including major hepatectomies, extended hepatectomies with biliary reconstruction and difficult segmentectomies of the posterior-superior segments, robotic surgery appears to emerge as a reasonable alternative to open surgery rather than being an alternative to laparoscopic procedures.

Cytomegalovirus Treatment Strategy After a Liver Transplant: Preemptive Therapy or Prophylaxis for Cytomegalovirus Seropositive Donor and Recipient

OBJECTIVES

Cytomegalovirus infections cause the most frequent infection after solid-organ transplant. While Cytomegalovirus prophylaxis is established in high-risk patients (donor+/ recipient-), data on Cytomegalovirus prophylaxis in other serostatus constellation are rare. The aim of this study was to evaluate the influence of Cytomegalovirus treatment strategy after a liver transplant (preemptive therapy vs general prophylaxis) in the largest group of patients: Cytomegalovirus seropositive donor and recipient.

MATERIALS AND METHODS

Forty-seven seropositive recipients of seropositive donor liver transplants (D+/R+, 2005-2012) were included in this retrospective study. Twenty-one patients received oral valganciclovir as Cytomegalovirus prophylaxis 100 days after transplant. Cytomegalovirus infection and Cytomegalovirus disease were monitored during the first 6 months.

RESULTS

A Cytomegalovirus infection could be detected in 4 out of 47 patients (8.5%), including Cytomegalovirus disease in 2 patients (Cytomegalovirus pneumonia and Cytomegalovirus-CNS disease). Three of these patients received no Cytomegalovirus prophylaxis (P = .408). Eight patients developed a graft failure; this occurred more frequently among patients without Cytomegalovirus prophylaxis (P = .044). Patients receiving Cytomegalovirus prophylaxis more often developed leukopenia. No difference was seen regarding the number of platelets, hemoglobin, and creatinine.

CONCLUSIONS

Cytomegalovirus prophylaxis can minimize the risk of Cytomegalovirus reactivation and graft failure. However, disadvantages of the prophylaxis as leukopenia should be considered.

Prognostic factors for kidney allograft survival in the Eurotransplant Senior Program

BACKGROUND

The shortage of organ donors has led to the introduction of the Eurotransplant Senior Program (ESP) to optimize the allocation of kidneys from elderly donors by age-matching. In the face of a rapidly aging population, identification of prognostic factors for kidney allograft survival within the ESP population will be of enormous significance.

MATERIAL AND METHODS

Donor and recipient data from 89 patients transplanted under the ESP protocol between 1999 and 2007 were retrospectively analyzed. Data were correlated with initial graft function, graft survival, acute rejection episodes, serum creatinine levels, glomerular filtration rates, and patient survival using univariate and multivariate analysis. Maximum follow-up was 5 years.

RESULTS

Cold ischemia time (CIT) >16 hours, body mass index (BMI) ≥25 kg/m(2), and kidney re-transplantation were significant risk factors for delayed graft function (DGF). Odds ratio for primary non-function was significantly increased with prolonged CIT, BMI ≥25 kg/m(2), and duration of renal replacement therapy >69 months. CIT >15 h, DGF, and kidney re-transplantation were associated with poor graft survival (P<0.05).

CONCLUSIONS

Risk reduction (e.g., aiming at CIT <15 h) and close surveillance of patients at risk appear to be crucial for allograft survival in the ESP.

Gender and strain-specific differences in the development of steatosis in rats

Non-alcoholic fatty liver disease (NAFLD) is a common problem with a wide variety of phenotypes. While its pathogenesis is still not fully understood, several risk factors for disease progression have been identified. Therefore, defining adequate animal models may serve to unreveal the pathogenesis in NAFLD. We studied Lewis and Sprague-Dawley rats of both genders (n = 6) fed standard (Std) or high-fat (HF) diet for three weeks. Disease stage was assessed by haematoxylin-eosin, Azan Heidenheim and Oil-Red staining, apoptosis by single-stranded DNA (ssDNA) detection and liver regeneration by Ki-67 staining. Serum markers of liver injury and lipid metabolism including adipocytokines were analysed. Livers of both strains and genders fed with HF diet demonstrated evidence of steatosis. Lewis rats developed microvesicular steatosis whereas Sprague-Dawley rats presented macrovesicular steatosis accompanied by pronounced fibrosis. Female gender of both strains was associated with lower steatosis grade and higher proliferation rate (P < 0.05). Gender-specific differences were most prominent in Lewis rats on a HF diet, where females showed lower alkaline phosphatase, cholesterol, triglyceride and leptin levels and a more favourable low-density lipoprotein/high-density lipoprotein ratio than males (P < 0.05). Reverse transcriptase-polymerase chain reaction analysis was performed to demonstrate changes in expression of various genes important for liver regeneration, fibrosis and steatosis. HF diet induced downregulation of proangiogenic genes such as vascular endothelial growth factor receptor 1 and 2 (P < 0.05) in males was not present in females. In conclusion, strain and gender served major roles in disease progression. These differences should be considered when designing studies and may offer new ways to advance therapeutic strategies.

Influence of heme oxygenase-1 on microcirculation after kidney transplantation

BACKGROUND

Cytoprotective proteins, such as heme oxygenase-1 (HO-1), play a decisive role in ischemia-reperfusion injury during kidney transplantation. The aim of this study was to investigate the impact of heme oxygenase-1 on microcirculation and on ischemia-reperfusion injury in an isogenic kidney transplantation rat model.

MATERIALS AND METHODS

Seventy male Lewis rats were distributed into three groups. In Group 1(control), the kidneys were only mobilized. In Groups 2 and 3, bilateral nephrectomy was performed, and a kidney from another Lewis rat was orthotopically transplanted on the left side. The donor animals in Group 3 received preconditioning with the HO-1 inductor hemin. 24 h after reperfusion graft function and morphology were examined. Microcirculation was investigated by in vivo microscopy of the renal surface 1 h after reperfusion.

RESULTS

HO-1 preconditioning led to significantly lower serum creatinine and serum urea, as well as less histological damage and inducible nitric oxide synthase expression. Microcirculation was improved by a significant enlargement of the vascular diameter and an increase of the capillary flow.

CONCLUSIONS

Treatment with hemin improves microcirculation by induction of HO-1 and reduces ischemia-reperfusion injury after kidney transplantation. HO-1 induction was shown to be a promising approach in the preconditioning of donor kidneys.

Recurrent Complicated Colon Diverticulitis in Renal Transplanted Patient

Colon perforation due to diverticulitis is a life-threatening complication in the postoperative course of kidney transplantation. In the immunocompromised patient a diagnosis of diverticulitis is difficult to make. We report a 53-year-old woman being kidney transplanted 14 years ago with known diverticulosis. She was admitted with acute severe pain in the lower left abdomen. Abdominal computed tomography (CT) scan indicated a diagnosis of intestinal abscess in the small pelvis. Laparotomy showed a covered sigma perforation with abscess located in the small pelvis (Hinchey-I). Because of the immunocompromised situation of the patient we performed a Hartmann procedure. Her postoperative course was uneventful. In a 6-month interval the intestinal continuity restoration was performed. Twelve days after discharge the patient was readmitted with reduced renal function and increased infection parameters. During physical examination the abdomen was tender. The patient complained of abdominal pain in the left upper abdomen and additional pain in the left shoulder. An antibiotic therapy using ciprofloxacin was already initiated owing to a urinary tract infection. An abdominal CT scan was performed and indicated an intestinal abscess in the left upper abdomen. Laparotomy showed an abscess involving transverse colon, distal jejunum, and proximal ileum (Hinchey-II). Segmental resection of the left colonic flexure, proximal jejunum, and ileum was performed. The postoperative course was uneventful and the patient was discharged on the 8th postoperative day. The present casuistry emphasizes that the immunocompromised patient can undergo diverticulitis twice, and that primary anastomosis is a feasible option for patients with localized peritonitis due to complicated diverticulitis.

Microsurgical training curriculum for learning kidney and liver transplantation in the rat

During the education of the next generation of scientists in experimental research, careful instruction in surgical techniques is of major importance. This applies in particular to complicated microsurgical models, which require a structured teaching concept with clearly laid-down working steps and adequate didactic resources. Transplantations in rats are undoubtedly among the most difficult models in experimental surgery. Because completely sutured orthotopic liver transplantation and kidney transplantation have been practiced for many years in our Surgical Research Unit, techniques must be transmitted to future generations. A microsurgical training program has been set up with the aim of being efficient, transparent, and motivating. Simply learning-by-doing in the sense of "laissez-faire" is ineffective and costly. Our training program is based on "three-phase didactics," in which the learning targets are presented in sequence and are clearly defined. This report is intended to give a brief overview of the principal transplantation models and to serve as a guide for teaching these models.

Auxiliary partial orthotopic liver transplantation: treatment of acute liver failure in a new rat model

BACKGROUND AND AIMS

Liver regeneration and functional interaction between native liver and graft after auxiliary partial orthotopic liver transplantation (APOLT) are not entirely understood and, therefore, require an experimental model simulating the clinical features of acute liver failure (ALF) and the surgical technique of APOLT.

MATERIALS AND METHODS

ALF was induced by subtotal hepatectomy in 50 Lewis rats (200-250 g). Sham operation (I), ALF without treatment (II), ALF with portocaval shunt for decreasing blood flow of the remnant liver (III), and ALF treated by APOLT (IV) were performed. The auxiliary graft represented a left donor liver lobe which was orthotopically implanted using a microsurgical technique including reconstruction of the graft artery and internal biliary drainage. Operative outcomes, serum chemistry and histopathological findings were examined up to the 14th day.

RESULTS

ALF without treatment (groups II and III) led to a small droplet fatty degeneration in the hepatocytes and a significant increase of liver parameters until the death of the animals within the first two postoperative days ( P<0.05). After APOLT (group IV), 80% of the animals survived up to the 14th day, revealing significantly decreased liver parameters ( P<0.05), a well-perfused graft and an up to five times increased native liver size with normal architecture.

CONCLUSION

This new rat model simulates the clinical features of an ALF treated by APOLT and is especially interesting for further basic research on the interaction between native liver and auxiliary graft after APOLT.