Endovascular isolated hepatic perfusion under pneumoperitoneum.

AIMS: Isolated hepatic perfusion (IHP) allows loco-regional administration of high drug doses for cancer treatment. Minimally invasive endovascular occlusion techniques can be used for IHP, but control of leakage remains a major drawback. We hypothesized that the increased intraabdominal pressure generated by a CO(2)-pneumoperitoneum (PP) can reduce the leakage rate of hypoxic endovascular IHP by mechanical compression of the capillary beds connecting the liver to the systemic circulation. METHODS: IHP was performed on adult pigs through laparotomy using a fenestrated double balloon-catheter placed into the retrohepatic vena cava to collect the hepatic outflow which was reinfused into the hepatic artery through an extracorporeal circulation system. Each pig underwent IHP during four consecutive phases: abdomen open (Phase I), abdomen closed under a 15 and 20 mmHg pneumoperitoneum (Phase II and III, respectively) and abdomen re-opened (Phase IV). The leakage rate from the liver to the systemic circulation was continuously monitored using a nuclear medicine technique. The systemic arterial pressure, the IHP inflow and outflow pressures and the flow rate were recorded. RESULTS: Leakage from the hepatic extracorporeal circulation to the systemic circulation occurred in all animals during Phase I. Under PP (Phases II and III), two leakage profiles were observed: (1) a major increase of the leakage rate in two animals with a high differential pressure (>50 mmHg) between the IHP inflow and the systemic pressures; (2) no change or a decrease of the leakage rate in the other three animals who had a low or negative differential pressure (<30 mmHg). Leakage was undetectable in all animals after exsufflation of the PP (Phase IV). CONCLUSIONS: IHP under PP is feasible. Leakage is not reduced during PP. A high gradient between the IHP inflow and the systemic pressure increases systemic leakage during PP. Upon release of the PP, the leakage is most likely redirected towards the volume depleted low resistance portal territory.

Leptin inhibits directly glucocorticoid secretion by normal human and rat adrenal gland.

Different interactions have been described between glucocorticoids and the product of the ob gene leptin. Leptin can inhibit the activation of the hypothalamo-pituitary-adrenal axis by stressful stimuli, whereas adrenal glucocorticoids stimulate leptin production by the adipocyte. The present study was designed to investigate the potential direct effects of leptin to modulate glucocorticoid production by the adrenal. Human adrenal glands from kidney transplant donors were dissociated, and isolated primary cells were studied in vitro. These cells were preincubated with recombinant leptin (10(-10)-10(-7) M) for 6 or 24 h, and basal or ACTH-stimulated cortisol secretion was subsequently measured. Basal cortisol secretion was unaffected by leptin, but a significant and dose-dependent inhibition of ACTH-stimulated cortisol secretion was observed [down by 29 +/- 0.1% of controls with the highest leptin dose, P < 0.01 vs. CT (unrelated positive control)]. This effect of leptin was also observed in rat primary adrenocortical cells, where leptin inhibited stimulated corticosterone secretion in a dose-dependent manner (down by 46 +/- 0.1% of controls with the highest leptin dose, P < 0.001 vs. CT). These effects of leptin in adrenal cells are likely mediated by the long isoform of the leptin receptor (OB-R), because its transcript was found to be expressed in the adrenal tissue and leptin had no inhibitory effect in adrenal glands obtained from db/db mice. Therefore, leptin inhibits directly stimulated cortisol secretion from human and rat adrenal glands, and this may represent an important mechanism to modulate glucocorticoid levels in various metabolic states.

Food-dependent Cushing's syndrome: possible involvement of leptin in cortisol hypersecretion.

Stimulation ofcortisol secretion by food intake has been implicated in the pathogenesis of some cases of ACTH-independent Cushing's syndrome, via an aberrant response of the adrenal glands to gastric inhibitory polypeptide (GIP). We report here a novel case of food-dependent Cushing's syndrome in a patient with bilateral macronodular adrenal hyperplasia. In this patient we were able to confirm a paradoxical stimulation of cortisol secretion by GIP in vivo as well as in vitro on dispersed tumor adrenal cells obtained at surgery. In addition to GIP, in vitro stimulation of these cultured tumor adrenal cells with leptin, the secreted product of the adipocyte, induced cortisol secretion. By comparison, no such stimulation was observed in vitro in adrenal cells obtained from another patient with bilateral macronodular adrenal hyperplasia and Cushing's syndrome that did not depend on food intake, in tumor cells obtained from a solitary cortisol-secreting adrenal adenoma, and in normal human adrenocortical cells. These results demonstrate that as in previously described cases of food-dependent Cushing's syndrome, GIP stimulated cortisol secretion from the adrenals of the patient reported here. Therefore, they indicate that such a paradoxical response probably represents the hallmark of this rare condition. In addition, they suggest that leptin, which normally inhibits stimulated cortisol secretion in humans, participated in cortisol hypersecretion in this case. Further studies in other cases of food-dependent Cushing's syndrome, however, will be necessary to better ascertain the pathophysiological significance of this finding.

NPY regulates catecholamine secretion from human adrenal chromaffin cells.

The aim of the present work was to find out whether NPY synthesized in human adrenal chromaffin cells controls in an autocrine/paracrine fashion the release of catecholamines by these cells. Accordingly, the constitutive and regulated release of both NPY and catecholamines was measured simultaneously in cultured human chromaffin cells. In addition, by using both RT-PCR and a combination of specific agonists and antagonists, we characterized the expression of NPY receptors on these cells as well as their pharmacology. Our results were as follows. 1) Human chromaffin cells constitutively secrete NPY. 2) Nicotine elicits a rapid increase in the release of both catecholamines and NPY; this release of NPY is more sustained than that of catecholamines. 3) RT-PCR shows expression of Y1, Y2, Y4, and Y5 receptor mRNA by chromaffin cells; these receptors are functional, as various receptor specific agonists elicit an increase in intracellular calcium. 4) Peptide YY, in contrast to NPY, is not able to stimulate the release of catecholamines. This finding was corroborated by the observation that no receptor-specific antagonists were able to reduce constitutive catecholamine release, whereas an NPY-immunoneutralizing antibody markedly attenuated the secretion. Taken together, these data suggest that NPY originating from the adrenal medulla locally enhances the secretion of catecholamines, presumably by acting via the putative y3 receptor.

Effect of liver transplantation on hepatic glucose metabolism in a patient with type I glycogen storage disease.

BACKGROUND: In type I glycogenosis, mutation of the glucose-6-phosphatase gene results in absent glucose-6-phosphatase activity in liver cells leading to fasting hypoglycemia. Liver transplantation is expected to normalize glucose homeostasis. METHODS: Endogenous glucose production (6,6 2H2 glucose) was measured after an overnight fast and during exogenous 13C-labeled glycerol infusion in a patient with glycogenosis type I 24 months after liver transplantation and in a group of healthy subjects. RESULTS: Compared with healthy subjects, the glycogenosis patient had normal fasting glucose production and glucose and insulin concentrations after liver transplantation, but mildly elevated plasma glucagon concentrations. Gluconeogenesis from exogenous glycerol (13C glucose synthesis) was similar and did not lead to enhancement of glucose production in both healthy controls and the patient. CONCLUSIONS: Liver glucoregulatory function is restored by orthotopic liver transplantation in type I glycogenosis.

Clinical value of immunoscintigraphy in colorectal carcinoma patients: a prospective study.

Fifty-seven patients with suspected CEA-producing tumors were studied prospectively by radioimmunoscintigraphy (RIS) using a 123I-labeled anti-CEA monoclonal antibody (MAb) (essentially the F(ab')2 or Fab fragments) and emission computed tomography (ECT). Results of RIS were compared to those of a comprehensive diagnostic study. Final diagnosis was based on surgery, biopsy and autopsy (n = 39) or follow-up findings (n = 18). Three groups of patients were defined: Group A with suspected primary tumors (n = 11), Group B with probable (n = 19) and Group C with questionable (n = 27) tumor relapse. Eighty-eight per cent, 93% and 71% of the anatomic regions studied were correctly identified as being involved, and 97%, 97%, and 87% as being free from tumor in Groups A, B, and C, respectively. In the 27 patients from Group C with no definite diagnosis of relapse, and in whom diagnosis was most difficult, 38 tumor sites were involved. Of these, 21 were detected by both prospective RIS and repeated comprehensive study, six by RIS only and seven by conventional methods only. Four sites remained undetected by both approaches. Ten of the 21 lesions were detected by RIS more than 1 mo earlier than by any other method. Among the seven tumor sites detected by other diagnostic modalities only, three were identified at the time of RIS and four became positive more than 6 mo later. Overall diagnosis was entirely correct in 30, partially correct in 16 and incorrect in six patients studied. RIS with ECT and 123I-labeled anti-CEA MAb allows early detection of recurrence or metastasis of colorectal cancer. It thus contributes to reduced delay between diagnosis and treatment.

Transplantation of encapsulated bovine chromaffin cells in the sheep subarachnoid space: a preclinical study for the treatment of cancer pain.

Chromaffin cells have been shown to release a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides. The allogeneic transplantation of chromaffin cells in the subarachnoid space has been shown to alleviate pain in various rodent models and possibly in terminal cancer patients. Because of the shortage of human cadaver donor tissue, we are investigating the possibility of transplanting xenogeneic cells in polymer capsules. In this technique, cells are surrounded by a permselective synthetic membrane whose pores are suitably sized to allow diffusion of nutrients, neurotransmitters and growth factors, but restrict the diffusion of the large molecules of the immune system and prevent contact with immunocompetent cells. The encapsulation technique therefore allows transplantation of xenogeneic tissue between species as well as retrieval of transplanted cells. Previously we have reported that encapsulated bovine chromaffin cells survive and alleviate pain in various rodent models. The purpose of the present study was to assess the feasibility of implanting a human sized device in a large animal model. Adrenals from 5 calves were surgically removed; chromaffin cells were isolated from these glands using a collagenase-based digestion-filtration technique. Cells were loaded into acrylic-based tubular (5 cm long, 920 microns wide) permselective capsules attached to silicone tethers. The capsules were maintained in vitro for at least 7 days following the encapsulation procedure. Nicotine evoked release was analyzed in a defined subgroup from each batch. One capsule was then implanted using a guiding cannula system in the lumbar subarachnoid space of each sheep for 4 (n = 5) and 8 (n = 1) wk. All capsules were retrieved intact by gentle pulling on the silicone tether. Except for one capsule, the evoked catecholamine release of the retrieved capsules was in the same range as that of other capsules from the same cohort that had been maintained in vitro. All retrieved capsules were devoid of host cell reaction. Clusters of viable cells dispersed in an alginate immobilizing matrix were observed throughout all the implanted capsules. This study demonstrates the feasibility of transplanting functional encapsulated xenogeneic chromaffin cells into the cerebrospinal fluid of a large animal model using a capsule of appropriate dimensions for human implants. We believe that these results suggest the appropriateness of human clinical trials in patients suffering from refractory terminal cancer pain.

Meropenem (1.5 g/day) is as effective as imipenem/cilastatin (2 g/day) for the treatment of moderately severe intra-abdominal infections.

This multicentre, open-label, randomised trial compared meropenem (0.5 g/8 h) and imipenem/cilastatin (at the commonly used dosage of 0.5 g/6 h) in monotherapy in patients with moderately severe intra-abdominal infections (IAIs). In total, 161 patients were randomised (82 meropenem, 79 imipenem/cilastatin). The mean APACHE II scores in the two groups were 5.8 and 6.4, respectively. At the end of therapy, 65/71 (91.6%) evaluable meropenem recipients were clinically cured or improved, compared to 60/64 (93.8%) imipenem/cilastatin recipients. This difference and that in an intention-to-treat analysis (82.1 vs 86.1%, respectively), were not statistically significant. Both drugs were generally well tolerated. Thus, meropenem 0.5 g/8 h is as clinically effective and well tolerated as imipenem/cilastatin 0.5 g/6 h in moderately severe IAIs.

Prophylaxis and treatment of infections complicating abdominal surgery.

The suitability of commonly used antimicrobial regimens for prophylaxis in abdominal surgery and treatment of intra-abdominal sepsis is discussed. These various therapies are often limited in their usefulness by the range of microorganisms against which they are effective and thus, to extend the antimicrobial cover, agents may be combined. Some forms of therapy may produce adverse effects in susceptible patients, thus limiting their use to certain groups, or there may be cost constraints. Beta-lactamase-inhibiting compounds appear to offer an optimal combination of a broad spectrum of activity against aerobic and anaerobic microorganisms, minimal toxicity and reasonable cost.

Amoxycillin/clavulanic acid prophylaxis in elective colorectal surgery: a prospective randomized trial.

In a randomized trial of 440 patients undergoing elective colorectal surgery, the prophylactic efficacy and the safety of amoxycillin/clavulanic acid were compared with that of a control regimen of clindamycin and gentamicin. Surgical wound healing was assessed by the ASEPSIS points scale; it was normal in 86% of patients and the scores for both groups were not statistically different (amoxycillin/clavulanic acid: 11.1; clindamycin + gentamicin: 10.9). Intra-abdominal infections were more frequent in the clindamycin + gentamicin arm of the study (Fisher's exact test, P = 0.035). It is concluded that amoxycillin/clavulanic acid is as effective and safe as clindamycin + gentamicin in the prevention of wound infection and may provide better protection against intra-abdominal infections.

Mechanisms of postprandial hyperglycemia in liver transplant recipients: comparison of liver transplant patients with kidney transplant patients and healthy controls.

Impaired glucose tolerance or diabetes mellitus are frequent complications after organ transplantation, and are usually attributed to glucocorticoid and immunosuppressive treatments. Liver transplantation results in total hepatic denervation which may also affect glucoregulation. We therefore evaluated postprandial glucose metabolism in a group of patients with liver cirrhosis before and after orthotopic liver transplantation. Seven patients with liver cirrhosis of various etiologies, 6 patients having received a kidney transplant, and 6 healthy subjects were studied. Their glucose metabolism was evaluated in the basal state and over 4 hours after ingestion of a glucose load with 6.6 (2) H glucose dilution analysis. The patients with liver cirrhosis were studied before, and again 4 weeks (range 2-6) and 38 weeks (range 20-76, n=6) after orthotopic liver transplantation. Basal glucose metabolism was similar in liver and kidney transplant recipients. Impaired glucose tolerance was present in both groups, but postprandial hyperglycemia was exaggerated and lasted longer in liver transplant patients. Postprandial insulinemia was lower in liver transplant recipients, while C-peptide concentrations were comparable to those of kidney transplant recipients, indicating increased insulin clearance. Glucose turnover was not altered in both groups of patients during the initial 3 hours after glucose ingestion, but was higher in liver transplant early after transplantation during the fourth hour. Postprandial hyperglycemia remained unchanged in liver transplant recipients 38 weeks after liver transplantation, despite substantial reduction of immunosuppressive and glucocorticoid doses. We conclude that liver transplant recipients have severe postprandial hyperglycemia which can be attributed to insulinopenia (secondary, at least in part, to increased insulin clearance) and a late increased glucose turnover. These changes may be secondary to hepatic denervation.

Isolated liver perfusion for non-resectable liver tumours: a review.

Many treatments have been proposed for non-resectable primary or secondary hepatic cancer but the results have generally been disappointing. Isolated Hepatic Perfusion (IHP) was first attempted four decades ago but it gained acceptance only recently, after spectacular tumour responses were obtained by isolated limb perfusion with melphalan and tumour necrosis factor (TNF) for melanomas and sarcomas. Surgical isolation of the liver is a technically demanding operation that allows the safe administration of high doses of chemotherapeutics and TNF. Percutaneous techniques using balloon occlusion catheters are simpler but result in higher leakage rates from the perfusion circuit into the systemic circulation. Several phase I-II trials indicate that IHP can yield high tumour response rates, even when there is resistance to systemic chemotherapy. However, no significant advantage in overall survival has been demonstrated so far. IHP offers unique pharmacokinetic advantages for locoregional chemotherapy and biotherapy. It might also allow gene therapy with limited systemic exposure and toxicity. At present, IHP nevertheless remains an experimental treatment modality which should therefore be used in controlled trials only.

Limb salvage by neoadjuvant isolated perfusion with TNFalpha and melphalan for non-resectable soft tissue sarcoma of the extremities.

AIMS: Patients with non-resectable soft tissue sarcomas of the extremities do not live longer if they are treated by amputation or disarticulation. In order to avoid major amputations, we tested isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF)+melphalan+/-interferon-gamma (IFN) as a pre-operative, neoadjuvant limb salvage treatment. METHODS: Twenty-two patients were included (six men and 16 women; three upper limb and 19 lower limb tumours). The AJCC stage was IIA in four patients, III in seven and IV in 11. Thirteen cases were recurrent or progressive after previous therapy; five tumours had a diameter >/=20 cm, and four were multiple or regionally metastatic. There were six malignant fibrous histiocytomas, five liposarcomas, four malignant peripheral nerve sheath tumours, three rhabdomyosarcomas, two leiomyosarcomas, one recurrent extraskeletal osteosarcoma and one angiosarcoma. RESULTS: Twenty-four ILPs were performed in the 22 patients, and 18 (82%) experienced an objective response: this was complete in four (18%) and partial in 14 (64%). Three patients had a minimal or no response and the tumour progressed in one case. All patients had fever for 24 hours but only one developed a reversible grade 3 distributive shock syndrome with no sequelae. There was no grade 4 toxicity. Seventeen patients (77%) underwent limb-sparing resection of the tumour remnants after a median time of 3.4 months: 10 resections were intracompartmental and seven extracompartmental. Surgery included flaps or skin grafts in five patients, arterial replacement in two and knee arthrodesis in one. Adjuvant chemotherapy was given to eight patients and radiotherapy to six. In one patient amputation was necessary after a second ILP. Secondary amputations were performed for recurrence in two patients, resulting in an overall limb salvage rate of 19/22 (86%). After a median follow-up of 18.7 months, 10 recurrences were recorded: seven were both local and systemic and three were only local. The median disease free and overall survival times have been >12.5 and 18.7 months respectively: this is similar to the outcome after primary amputations for similar cases. CONCLUSION: ILP with TNF and chemotherapy is an efficient limb sparing neoadjuvant therapy for a priori non-resectable limb soft tissue sarcomas.

Long-term follow-up after a distal splenorenal shunt procedure. A clinical and hemodynamic study.

Of 26 patients who underwent distal splenorenal shunting 4 or more years ago (1969 to 1978), 10 died 3 to 87 months postoperatively (mean 38.5 months). Six deaths were due to liver failure, two to hemorrhagic peptic ulcer disease (the shunt remained patent in each patient), one to brain hemorrhage, and one to sepsis. Eight of the surviving patients resumed professional activity, one showed transient signs of encephalopathy, one had a single episode of recurrent variceal bleeding that could be managed conservatively, and no patient had ascites. Eight patients were investigated angiographically and endoscopically. Preoperative and postoperative measurements of the portal vein showed a decreased diameter in five patients and no opacification in the other three 29 to 97 months after surgery. At endoscopy four patients had small residual esophageal varices, one patient had none, and the other three had large varicosities with variceal pressures between 30 and 40 cm H2O in two and above 40 cm H2O in one. Although the incidence of postoperative encephalopathy and variceal bleeding was low after distal splenorenal shunting, the operation did not prevent a decrease in hepatopetal portal flow and did not always abolish the esophageal varices.

Endoscopic noninvasive manometry of esophageal varices: prognostic significance.

Our study attempts to establish a relation between the pressure in the esophageal varices and the clinical outcome in 18 patients in whom sclerotherapy for bleeding esophageal varices was performed. The measured pressure was compared to the endoscopic findings. Before sclerotherapy, a noninvasive manometric measurement was performed on the varices using a spheric membrane manometer fixed at the tip of an endoscope. Twelve of our 18 patients suffered repeated hemorrhage which led to death in five. We discovered a relation between the measured pressure and the outcome. Beside this, we measured the highest pressures in the largest varices. The relation that seems to exist between the pressure in the esophageal varices, the endoscopic findings, and the severity of the portal hypertension may provide new opportunities for research in this field.

The duodenal diverticulum: an exceptional site of massive bleeding.

Duodenal diverticula are usually asymptomatic but may induce major hemorrhage on rare occasions. When endoscopy cannot determine the cause of bleeding, angiography must be performed. This paper describes a patient in whom angiography identified the diverticulum as the bleeding source, which was an exceptional occurrence, and thereby allowed prompt, appropriate treatment.

Strain gauge plethysmographic studies after clipping of the inferior vena cava.

Assessment of the hemodynamic effects of the IVC clipping by strain gauge plethysmography provides accurate quantitative data. These correlate very well with the other means of investigation used in the study. Eight patients were controlled in the Vascular Laboratory 9 to 43 months after clipping of the inferior vena cava. They submitted to clinical evaluation, Doppler ultrasound, isotopic venography, abdominal sonography, and strain gauge plethysmography of the lower extremities. This last method provided quantitative data; maximal venous outflow was found to be equivalent in the 8 patients included in the study and in a control group of 20 healthy young volunteers. Strain gauge plethysmography results correlate well with the other means of investigation and demonstrate the efficacy of the dilated venous collateral channels in restoring a normal venous return.

Faecaloid breath heralding secondary aorto-enteric fistula.

A patient underwent simultaneous abdominal aortic prosthetic replacement and resection of a Meckel diverticulum. He then developed faecaloid breath. Later reoperation for aorto-enteric fistula cured halitosis. We conclude in retrospect that faecaloid breath may herald a secondary aorto-enteric fistula. A pathophysiological mechanism is suggested and discussed.