[First national survey on use of robotics for visceral surgery in Germany]. / Erste nationale Umfrage zum Operationsrobotereinsatz in der Viszeralchirurgie in Deutschland.

BACKGROUND: The operation robot is the most advanced technology available in minimally invasive surgery for facilitating complex surgical procedures and is increasingly used in visceral surgery; however, to date no data are available concerning its use in visceral surgery in Germany. OBJECTIVE: The aim of the survey was to document the development and current state of the art of robotics for visceral surgery in Germany. MATERIAL AND METHODS: All 41 surgical departments with access to the da Vinci robot were invited to participate in the survey. Data were acquired with a specially designed Excel spreadsheet, documenting all procedures and also the dignity in gastrointestinal operations for each year since inception of the robot program up to 2015. RESULTS: Of the 41 surgical departments with an active robotic program only 23 participated in the analysis. The overall volume rose steadily from 4 procedures in 2010 to 50 in 2012, 106 in 2013, 441 in 2014 and reached 819 in 2015. In this period 2 centers had > 200 operations, 1 center had 150, 3 centers had ≥ 100, 3 departments had ≥ 50 and 14 departments had < 50 operations. The type of robotic procedures used encompassed the full scope of laparoscopic surgery. Colorectal surgery was predominant with 50 % of all procedures and was performed in 87 % of the departments. Thymus resections amounted to 10 % of all surgical procedures and gastric surgery to 9 %. Approximately 5 % of all cases involved the esophagus, gall bladder and pancreas. Hepatic surgery amounted to only 2.4 % and all other operations even less and were performed in only a few departments. CONCLUSION: Despite a doubling of procedures in recent years, robotics is still in the initial phase for visceral surgery in Germany.

Validation of methodologies for quantifying isolated human islets: an Islet Cell Resources study.

BACKGROUND: Quantification of islet mass is a crucial criterion for defining the quality of the islet product ensuring a potent islet transplant when used as a therapeutic intervention for select patients with type I diabetes. METHODS: This multi-center study involved all eight member institutions of the National Institutes of Health-supported Islet Cell Resources Consortium. The study was designed to validate the standard counting procedure for quantifying isolated, dithizone-stained human islets as a reliable methodology by ascertaining the accuracy, repeatability (intra-observer variability), and intermediate precision (inter-observer variability). The secondary aim of the study was to evaluate a new software-assisted digital image analysis method as a supplement for islet quantification. RESULTS: The study demonstrated the accuracy, repeatability and intermediate precision of the standard counting procedure for isolated human islets. This study also demonstrated that software-assisted digital image analysis as a supplemental method for islet quantification was more accurate and consistent than the standard manual counting method. CONCLUSIONS: Standard counting procedures for enumerating isolated stained human islets is a valid methodology, but computer-assisted digital image analysis assessment of islet mass has the added benefit of providing a permanent record of the isolated islet product being evaluated that improves quality assurance operations of current good manufacturing practice.

Regional bone loss after orthotopic liver transplantation in inbred rats: the role of hepatic denervation.

Bone loss and long-term persistence of osteoporosis with increased fracture risk are common after liver transplantation. It is unknown whether transplantation-induced disruption of hepatic nerves, serving numerous regulatory metabolic and sensory functions, is herein involved. To test this possibility, we measured bone mineral density (BMD) by peripheral quantitative computed tomography (pQCT) and studied dynamic histomorphometry, radiocalcium kinetics, and biochemical parameters in 7 liver-transplanted and 7 sham-operated inbred rats. Although liver function was normal in TX rats, trabecular BMD of the first lumbar vertebra and total BMD of the femoral diaphysis were decreased by 13% and 6%, respectively, 9 months postsurgery. The breaking force of the femur was significantly lower by 21%. However, bone mass in the femoral and tibial metaphysis was preserved as evidenced by pQCT measurements and histomorphometry. Trabecular width and wall thickness were significantly decreased in vertebral cancellous bone, whereas indices of bone formation and resorption were normal or slightly reduced. Serum minerals, mineral balance, fractional and net absorption of Ca and Mg, serum calciotropic hormones, IGF-I, leptin, specific activity of 45Ca in bone, 45Ca excretion, and biochemical indices of bone formation and bone resorption remained unchanged. We conclude that liver transplantation-related denervation causes cancellous and cortical bone loss in well-innervated bone sites such as the lumbar spine and the long bone diaphysis. Cancellous bone loss in TX rats is due to an impairment of osteoblast team performance and subsequent trabecular thinning. The mechanism uncovered by our study may contribute to long-term bone loss after liver transplantation.

The solution to hyperglucagonemia after pancreas transplantation in inbred rats.

BACKGROUND: We studied the possible role of the diseased host pancreas and site of venous graft drainage in the development of hyperglucagonemia after pancreas transplantation, to identify the crucial steps of the technique capable of eliminating hyperglucagonemia and its possible diabetogenic effect. METHODS: Therefore, we compared 4 groups of inbred rats: (1) heterotopic pancreas transplantation with either systemic (n = 9); or (2) portal (n = 5) venous drainage after prior induction of diabetes with streptozotocin; (3) orthotopic pancreaticoduodenal transplantation with portal venous drainage after prior pancreaticoduodenectomy (n = 7), and (4) sham-operation (Sham; n = 10). The postoperative period was 6 months. RESULTS: Only heterotopic transplantation with systemic venous drainage and loss of glucagon's first pass hepatic extraction, resulted in arterial hyperglucagonemia, whereas the arterial plasma insulin level was only slightly higher in comparison with the other groups. After either type of heterotopic transplantation the glucagon content of host pancreata remained unchanged, whereas the insulin content was approximately 5% of that in the pancreas of Sham rats. The insulin and glucagon contents of all grafts were similar to those of the control pancreas in Sham rats, and the insulin release was sufficient to normalize fasting plasma glucose and lipids after either type of transplantation. CONCLUSION: To remove the diseased host pancreas appears unnecessary, as the hyperglucagonemia and the concomitant slight hyperinsulinemia, capable of preventing glucagon's diabetogenic effects, are due to loss of the first pass hepatic extraction by systemic venous drainage alone. This disadvantage can be eliminated by portal venous graft drainage.

Metabolic consequences of orthotopic pancreaticoduodenal transplantation with preservation of near normal physiology.

BACKGROUND: Several case reports suggested the use of pancreaticoduodenal allotransplantation alone or in combination with multivisceral transplants to treat exocrine and endocrine deficiency after pancreatectomy for chronic pancreatitis, upper abdominal malignancies, and cystic fibrosis. Our objective was to establish the metabolic consequences of this technique. METHODS: Inbred rats, which either underwent pancreaticoduodenectomy before receiving an orthotopic duodenopancreas transplant (Tx, n= 18) or laparotomy (sham, n=18), were subjected 3 months postoperatively to oral and "isoglycemic" i.v. glucose tolerance tests with arterial blood sampling (n=12) or oral glucose tolerance test with additional portal blood sampling (n=6). Fecal fat and chymotrypsin were evaluated in the 11th postoperative week as indicators of pancreatic exocrine function in eight animals of each group. RESULTS: The incremental arterial plasma glucose integrated over a 90-min period was similar after oral and i.v. glucose in the respective groups, but was significantly lower in Tx versus sham rats after oral glucose. Incremental portal glucose was also lower after oral glucose, while hepatic glucose extraction remained unchanged. The incremental response of arterial glucose-dependent insulinotropic peptide, and of arterial and portal insulin, was comparable in Tx and sham rats; also in both groups the arterial response was significantly greater with oral versus i.v. glucose, and the incretin effect for insulin was intact after transplantation. Fecal fat and chymotrypsin levels did not differ between the two groups. CONCLUSIONS: 1) In the Tx rat lower incremental plasma glucose after oral glucose intake likely results from decreased intestinal glucose uptake; 2) preservation of a normal entero-insular axis of insulin together with the absence of intestinal malabsorption of lipids suggest that orthotopic transplantation of a duodeno-pancreas preserved endocrine and exocrine pancreatic function and therefore qualifies as treatment modality for the above named indications.

High insulin and low IGF-I plasma levels following pancreas transplantation in rats. Implications for bone and mineral metabolism.

Primary disturbances in mineral metabolism and deficiencies in insulin and insulin-like growth factor-I (IGF-I) have been implicated in the pathogenesis of diabetic osteopenia. This prompted us to investigate whether normal bone minerals and bone morphology are preserved after pancreas transplantation. To this end, 8 inbred rats (transplants) were compared with 9 sham-operated rats (controls) 20 months after orthotopic pancreas transplantation. While basal levels of insulin remained unaffected by transplantation, an oral glucose load elicited hyperinsulinemia (integrated incremental response: mean +/- SEM, 62+/-8 nmol l(-1) 60 min in transplants vs. 32+/-6 nmol l(-1) 60 min in controls; p<0.01) in the presence of normal glucose levels. Fecal and urinary excretion and fractional intestinal absorption of calcium, magnesium and phosphorus, net calcium absorption and the respective serum mineral levels were unchanged after transplantation, as were those of the calciotropic hormones. Serum osteocalcin and bone alkaline phosphatase remained unaffected, and urinary excretion of pyridinium and deoxypyridinium were unchanged. Fasting plasma IGF-I concentration was significantly decreased in transplants (930+/-42 ng ml(-1)) vs. control rats (1074+/-49 ng ml(-1); p < 0.05). Despite similar physical and chemical properties of bone in both groups, histomorphometry revealed slight osteopenia in transplant rats, as reflected by a 38% reduction in the cancellous bone area of the proximal tibial metaphysis. Plasma IGF-I levels were significantly correlated with bone mineral apposition rate (r=0.70, p<0.02), osteoblast perimeter (r=0.60, p<0.05) and osteoid perimeter (r=0.60, p<0.05). In conclusion, pancreas transplantation preserves physical and chemical properties of bone, but bone metabolism is not completely normal after transplantation, as evidenced by decreased cancellous bone. This might have resulted from the insulin resistance associated with the lowering of the plasma IGF-I level, which was correlated with the mineral apposition rate.

Effect of venous drainage site on insulin action after pancreas transplantation in the rat--is there insulin resistance and a risk for atherosclerosis?

The aim of the present study was to determine the influence of the venous drainage site on insulin homeostasis and the possible risk for atherosclerosis development after pancreas transplantation. We studied inbred rats that received pancreas transplants with either systemic (STX) or portal (PTX) venous drainage after prior induction of diabetes with streptozotocin and sham-operated controls. The observation period was 6 months. Fasting plasma glucose and insulin levels were similar in all 3 groups, but fasting plasma glucagon levels were elevated in STX (mean +/- SEM, 282+/-35 ng/L) in comparison to PTX rats (119+/-9 ng/L, P < .05), although the difference versus the control group (191+/-31 ng/L) was insignificant. Glucose utilization and hepatic glucose production (HGP), assessed by a dose-response euglycemic-hyperinsulinemic clamp in combination with tritiated glucose infusion, were similar in all 3 groups. The groups were also similar with respect to the molar ratio of plasma C-peptide and insulin during basal steady state and the metabolic clearance rate (MCR) of insulin during the clamp studies, suggesting an unchanged hepatic insulin extraction (HIE) after transplantation with either technique. Factors known to be related to atherosclerosis, ie, blood pressure, intracellular magnesium, and fasting levels of plasma cholesterol, triglycerides, and high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, were similar in all 3 groups. Light microscopy of the aorta showed a slightly thicker intima in STX rats (24.3+/-0.5 microm, P < .05) versus PTX rats (21.4+/-0.7 microm) and control (21.4+/-0.6 microm); however, atherosclerosis-like lesions were absent in all 3 groups. In conclusion, in a rat model with streptozotocin-diabetes and pancreas transplantation but no need for immunosuppression, both systemic and portal venous drainage avoid peripheral and hepatic insulin resistance; also, there is no increased risk for atherosclerosis.

Orthotopic pancreas transplantation with portal venous drainage in rats. Surgical technique and metabolic effects(*).

Heterotopic pancreas transplantation in type I diabetic patients does not correct hyperglucagonemia, which is thought to be due to insufficiently suppressed glucagon release by the host pancreas. The diabetogenic effects of glucagon then have to be corrected by higher than normal insulin secretion from the transplant, with the attendant risk of earlier loss of islet cell function, and development of atherosclerosis. To establish whether this situation can be prevented, we investigated glucose homeostasis and blood lipids, as well as fecal fat and chymotrypsin as indicators for pancreatic exocrine function 14 weeks after orthotopic pancreas transplantation in inbred rats. The pancreas was resected before orthotopic transplantation of the donor pancreas with portal venous drainage (n=8). Laparotomized animals served as controls (n=8). Basal plasma glucagon, basal plasma insulin to glucagon molar ratio, and basal and integrated incremental responses of plasma glucose, insulin, and C-peptide after an oral glucose load (2 g/kg body weight) were similar in both groups. However, hepatic insulin clearance was slightly but significantly lower in the transplanted group (1.1+/- 0.1 vs 1.6+/-0.2; P<0.05). Basal plasma levels of free fatty acids, phospholipids, triglycerides, cholesterol, low-density lipoproteins, and high-density lipoproteins were unchanged after transplantation. Also unchanged were fecal fat and chymotrypsin levels, thus indicating preserved pancreatic exocrine function. We concluded that orthotopic pancreas transplantation with portal venous drainage achieves almost optimal metabolic control with respect to endocrine and exocrine pancreatic function as well as blood lipids. This technique could therefore be used to treat combined endocrine and exocrine insufficiency in chronic pancreatitis and thus enlarges the spectrum of indications for pancreas transplantation.

Preservation of the incretin effect after orthotopic pancreas transplantation in inbred rats.

To establish whether the incretin effect is under neural control, insulin, C-peptide, and glucose-dependent insulinotropic peptide (GIP) responses and hepatic insulin clearance were investigated after oral and "isoglycemic" intravenous glucose in 12 inbred rats after denervation of the pancreas by orthotopic transplantation with portal venous drainage (Tx group) and in 12 laparotomized controls (sham group). Effective pancreas denervation was documented by a decreased pancreatic polypeptide (PP) response to insulin-induced hypoglycemia and by decreased levels of norepinephrine and calcitonin gene-related peptide (CGRP) in pancreatic tissue. Basal and incremental arterial plasma glucose integrated over 180 minutes did not differ between oral and intravenous glucose, but the integrated insulin response (mean +/- SEM) was significantly greater with oral versus intravenous glucose (Tx group, 104.9 +/- 22.0 v 31.0 +/- 4.9 nmol x L(-1) x min, P < .01; sham group, 79.5 +/- 10.6 v 36.6 +/- 5.8 nmol x L(-1) x min, P < .01). The integrated response of C-peptide was similar during both tests (Tx group, 105 +/- 14 v 79 +/- 8 pmol x mL(-1) x min; sham group, 112 +/- 10 v 121 +/- 12 pmol x mL(-1) x min). Hepatic insulin clearance was significantly decreased in both groups by oral compared with intravenous glucose administration (Tx group, 1.3 +/- 0.2 v 3.3 +/- 0.6 mmol/mmol, P < .01; sham group, 1.6 +/- 0.1 v 3.9 +/- 0.6 mmol/mmol, P < .02). The incretin effects for insulin (Tx group, 5.6 +/- 2.7; sham group, 3.0 +/- 0.8) and C-peptide (Tx group, 1.4 +/- 0.2; sham group, 1.1 +/- 0.2), calculated as the ratio of the integrated oral response and integrated intravenous response, and GIP responses to oral and intravenous glucose were not significantly different between the two groups. We conclude that there is preservation of the incretin effect in rats with orthotopically transplanted and hence extrinsically denervated pancreas, thus ruling out the possibility that the autonomic nervous system substantially contributes. Hepatic insulin clearance and insulinotropic hormones such as GIP appear to be more important.