Abdominal Compartment Syndrome: diagnostic evaluation and possible treatment

BACKGROUND

Abdominal compartment syndrome (ACS) is a clinical condition caused by an increase in intra-abdominal pressure. The incidence is variable, based on the type of patients taken into consideration, increasing exponentially in critical conditions, such as traumatized, burned patients in shock. The syndrome can also follow surgical procedures like transplantation of abdominal organs, for example configuring rare pictures such as RACS (post-transplant kidney syndrome). In most cases the symptoms are non-specific and varied according to the different etiology of the ACS, therefore the diagnosis may not be immediate.

AIM

The aim of this work is to evaluate the best therapeutic approach based on the evidence in the literature.

RESULTS

An early diagnosis, which can also identify the stages of intra-abdominal hypertension, is necessary to ensure the survival of the patient, implementing an integrated multidisciplinary treatment, expecially in the early stages of the development of the ACS.

CONCLUSIONS

The definitive treatment is surgical and is based on the decompression of the abdomen.

Loup-assisted technique to create arterio-venous fistulas in elderly. A single centre experience

AIMS

The radio-cephalic arteriovenous fistula (RCAVF) is the first choice treatment in end-stage renal disease patients. In the last few years, the hemodialysis population has shown a high percentage of elderly patients (> 65 year old) with comorbidities, mainly vascular diseases, which may adversely affect their vascular access success. The aim of this study was to evaluate the effectiveness of a loup-assisted technique to create RCAVFs in over 65 patients.

PATIENTS AND METHODS

98 consecutive patients with renal failure were prospectively observed. The patient were divided in relation to their age (> 65 year old; < 65 year old). In both groups, a microsurgical distal RCAVF was created. Statistics included the prevalence of distal RCAVF created, the incidence of immediate failure, the primary and secondary patency rate at one year.

RESULTS

Distal RCAVF was created in 82.60% of patients younger than 65 years and in 73.07% of patients older than 65 years, with no statistically significant difference. The incidence of immediate failure, the primary and secondary patency at one year were not statistically significant between the two groups.

CONCLUSIONS

Distal RCAVF should be the first choice vascular access even in ESRD elderly patients. The loup-assisted microsurgical fistula creation, allows to perform distal RCAVF with success, even in patients older than 65 years old, achieving similar results to younger patients.

[Risk factors' analysis of transient and permanent hypoparathyroidism after thyroidectomy]

AIMS

This review evaluates those main risk factors that can affect patients undergoing thyroidectomy, to reach a better pre- and post-operative management of transient and permanent hypoparathyroidism.

DISCUSSION

The transient hypoparathyroidism is a potentially severe complication of thyroidectomy, including a wide range of signs and symptoms that persists for a few weeks. The definitive hypoparathyroidism occurs when a medical treatment is necessary over 12 months. Risk factors that may influence the onset of this condition after thyroidectomy include: pre- and post-operative biochemical factors, such as serum calcium levels, vitamin D blood concentrations and intact PTH. Other involved factors could be summarized as follow: female sex, Graves' or thyroid neoplastic diseases, surgeon's dexterity and surgical technique. The medical treatment includes the administration of calcium, vitamin D and magnesium sometimes.

CONCLUSIONS

Although biological and biochemical factors could be related to iatrogenic hypoparathyroidism, the surgeon's experience and the used surgical technique still maintain a crucial role in the aetiology of this important complication.

The medical and surgical treatment in secondary and tertiary hyperparathyroidism. Review

INTRODUCTION

Hyperparathyroidism is an alteration of the pathophysiological parathyroid hormone (PTH) secretion due or an independent and abnormal release (primary or tertiary hyperparathyroidism) by the parathyroid or an alteration of calcium homeostasis that stimulates the excessive production of parathyroid hormone (secondary hyperparathyroidism).

AIMS

There is not a standard, clinical or surgical, treatment for hyperparathyroidism. We review current diagnostic and therapeutic methods.

DISCUSSION

In secondary hyperparathyroidism (2HPT) there is a progressive hyperplasia of the parathyroid glands and an increased production of parathyroid hormone. Several causes are proposed: chronic renal insufficiency, vitamin D deficiency, malabsorption syndrome. The tertiary hyperparathyroidism (3HPT) is considered a state of excessive autonomous secretion of PTH due to long-standing 2HPT and it's usually the result of a lack of suppression in the production of PTH. The pathophysiological implications are both skeletal and extraskeletal: it damages the cardiovascular system, nervous system, immune, hematopoietic and endocrine system. The introduction of new drugs has improved the survival of these patients, allowing the inhibition of the synthesis of PTH. Indication for surgical treatment is unresponsive medical therapy.

CONCLUSIONS

There are no large prospective studies that comparing the medical and surgical treatment. The choice is not unique and we have to consider the singolar case and the clinical condition of the patient.

Bone resorption in kidney transplant recipients

Early diagnosis of persistent hyperparathyroidism (HP) following kidney transplantation may prevent worsening of osteodystrophy and potential damage to the graft. We evaluated the utility of collagen pyridinoline (PYD) and deoxypyridinoline (DPD) urinary cross-links beyond the common HP markers to evaluate 70 selected stable recipients between 1997 and 2006 who were divided into 2 group depending on the immunosuppressive protocol. All patients showed elevated levels of urinary cross-links even though calcemia and phosphoremia values were normal. Their mean creatinine level was slightly increased. Data were assessed as mean values +/- SD. All variables underwent a correlation matrix analysis and a stepwise regression, with posttransplant intact parathyroid hormone (iPTH) as the dependent variable and other variables as regressors. A statistically significant correlation was observed between PYD and alkaline phosphatase (ALP; P = .0026, r = .41); PYD and DPD (P = .015, r = .34); pre- and posttransplant iPTH (P = .024, r = .31); and creatinine and ALP (P = .024, r = .31). Taking the groups separately, there were significant correlations between PYD and ALP (P = .0076, r = .42); PYD and DPD (P = .017, r = .38); ALP and posttransplant iPTH (P = .038, r = .33); osteocalcin (OC) and posttransplant iPTH (P = .048, r = .32); and pre- and posttransplant iPTH (P = .019, r = .37) among subjects in the first group, whereas subjects in the second group showed a correlation between posttransplant iPTH and age at transplantation (P = .032, r = .61). In conclusion, we showed that urinary cross-links may be helpful to reveal bone resorption in kidney recipients when usual bone metabolism parameters do not demonstrate hyperparathyroidism.

Robuvit® (French oak wood extract) in the management of functional, temporary hepatic damage. A registry, pilot study

AIM

The aim of this registry study was to evaluate the evolution of moderate functional hepatic failure (MTHF) using a proprietary new oak wood supplement (Robuvit®) extracted from Quercus Robur. Recent studies have indicated the protective effect of oak wood extracts on liver injury. Quercus wood extracts have shown hepatoprotective effect on initial induced liver-injury.

METHODS

This registry included a total of 75 patients with MTHF characterized by: decreased albumin levels; increased total bilirubin, altered hepatic functions enzymes, increased oxidative stress, negative viral hepatitis markers.

RESULTS

The two groups (best management in comparison with best management+ Robuvit®) were comparable: 32 Robuvit® patients and 29 comparable controls) completed the 12-week registry. At inclusion, the blood parameter values in the two groups were comparable. At the end of the supplementation period, the increase in albumin levels was significantly (P<0.05 at 12 weeks) faster and higher in the Robuvit® group. The decrease in ALT-SGPT and AST-ASAT was significant in the supplement group (P<0.05 at 4 and 12 weeks); the tests were normalized at 4 and 12 weeks. Controls remained out of the normal range for more than 12 weeks. Alkaline phosphatase was normalized at 4 and 12 weeks in Robuvit® patients; they were decreased, but not normalized in controls at 4 weeks (Robuvit® group's values were significantly better; P<0.05). Values were normalized in controls (significantly higher in comparison with Robuvit®; P<0.05) at 12 weeks. Total bilirubin was normalized in Robuvit® subjects at 4 and 12 weeks. Results were significantly better in comparison with controls (P<0.05). Direct bilirubin values increased more in the Robuvit® group at 4 and 12 weeks (P<0.05). Gamma GT values were normalized at 4 and 12 weeks in the Robuvit® group. There was a less important decrease in controls (P<0.05) without normalization at 12 weeks. Plasma free radicals increased at inclusion showed a significant decrease in Robuvit® subject (at 4 and 12 weeks) with normalization at 12 weeks. Persisting, elevated values in controls were observed even at 12 weeks (P<0.05). ESR and CRP decreased in both groups with a more important decrease in the Robuvit® group (P<0.05). Hepatitis markers were negative when repeated at 4 and 12 weeks.

CONCLUSION

Data from this pilot, supplement registry study indicate a significant protective activity of Robuvit®, associated with a very good safety profile, in patients with temporary hepatic failure. The activity of Robuvit® seems to be mediated by its anti-inflammatory activity.

Effect of autologous transplantation of bone marrow cells concentrated with the MarrowXpress system in patients with critical limb ischemia

Critical limb ischemia (CLI), a vascular disease affecting lower limbs, with high morbidity and mortality, is becoming a challenge due to the aging of the population. Patients without direct revascularization options have the worst outcomes. To date, 25% to 40% of CLI patients are not candidates for surgical or endovascular approaches, facing a major amputation as the ultimate option. This study sought to assess the safety and efficacy of transplantation of autologous bone marrow concentrates in "no-option" patients to restore blood perfusion by collateral flow and limb salvage. We performed a nonrandomized, noncontrolled pilot study for no-option CLI patients using intra-arterial infusion of autologous bone marrow concentrate. Variation of blood perfusion parameters, evaluated by laser doppler flowmetry after 6 and 12 months, was set as primary endpoint. Thirteen enrolled patients showed improvements in objective measurements of perfusion. This uncontrolled study provided evidence that transplantation of autologous bone marrow concentrates was well tolerated by CLI patients without significant adverse effects, demonstrating improved perfusion, confirming the feasibility and safety of the procedure.

Autologous bone marrow cell therapy for peripheral arterial disease

Inadequate blood supply to tissues caused by obstruction of arterioles and/or capillaries results in ischemic injuries – these injuries can range from mild (eg, leg ischemia) to severe conditions (eg, myocardial infarction, stroke). Surgical and/or endovascular procedures provide cutting-edge treatment for patients with vascular disorders; however, a high percentage of patients are currently not treatable, owing to high operative risk or unfavorable vascular involvement. Therapeutic angiogenesis has recently emerged as a promising new therapy, promoting the formation of new blood vessels by the introduction of bone marrow–derived stem and progenitor cells. These cells participate in the development of new blood vessels, the enlargement of existing blood vessels, and sprouting new capillaries from existing blood vessels, providing evidence of the therapeutic utility of these cells in ischemic tissues. In this review, the authors describe peripheral arterial disease, an ischemic condition affecting the lower extremities, summarizing different aspects of vascular regeneration and discussing which and how stem cells restore the blood flow. The authors also present an overview of encouraging results from early-phase clinical trials using stem cells to treat peripheral arterial disease. The authors believe that additional research initiatives should be undertaken to better identify the nature of stem cells and that an intensive cooperation between laboratory and clinical investigators is needed to optimize the design of cell therapy trials and to maximize their scientific rigor. Only this will allow the results of these investigations to develop best clinical practices. Additionally, although a number of stem cell therapies exist, many treatments are performed outside international and national regulations and many clinical trials have been not registered on databases such as ClinicalTrials.gov or EudraCT. Therefore, more rigorous clinical trials are required to confirm the first hopeful results and to address the challenging issues.

Circulating cytokines present in the serum of peripheral arterial disease patients induce endothelial dysfunction

Peripheral arterial disease (PAD) is a chronic condition caused by atherosclerosis and is a severe complication of type 2 diabetes (T2D). We hypothesised that chronic condition of arterial disease engenders inflammation and endothelial damage in response to circulating cytokines released in the blood stream of PAD patients. We explored the levels of circulating cytokines in PAD patients with and without diabetes by multiplex cytokine array compared with non-PAD controls. Serum from PAD patients with or without diabetes showed high levels of VEGF, IFN-gamma, TNF-alpha, MCP-1, and EGF. VEGF levels correlated with TNF-alpha and IFN-gamma, significantly. Endothelial cells (ECs) were exposed to the different altered cytokines to evaluate changes in cell growth, migration and tubule-like formation, displaying impairment on proliferation, migration and tubule formation. Our findings demonstrate that a set of cytokines is significantly increased in the serum of PAD patients. These cytokines act to induce endothelial dysfunction synergistically. VEGF strongly correlated with TNF-alpha and IFN-gamma, opening new therapeutic perspectives.

A case report of a difficult dissection of the iliac vessels conducted by means of the harmonic scalpel during a kidney transplantation

BACKGROUND

The "difficult" preparation of iliac vessels in the kidney transplant recipient caused by a perivascular fibrosis with satellite lymphadenopathy is sometimes burdened by post-transplant complications (lymphocele, seroma and hematoma). Both iliac vascular adhesions and satellite lymphoadenopaty are often due to reiterate femoral cannulation aimed to hemodialysis.

PATIENTS AND METHODS

The case report concerns a 60 years old female uremic patient, on dialysis for about 4 years with perivascular fibrosis and pelvic lymphadenopathy caused by bilateral femoral artery catheterization. In the course of kidney transplant, preparation of the iliac vessels was performed by ultrasonic scalpel. In the case we handled there was no incidence of immediate, medium and long term post operative complications, with a considerable reduction of the operative time in the vascular dissection performed without ligation. Often the long dialytic period, the same nephropathy, reiterative femoral catheterization determine perivascular fibrosis and/or consensual lymphadenopathy. In these cases, in light of initial experience, the use of ultrasonic scalpel enables easy dissection by the coagulative synthesis not only of vascular compartment but also of the lymphatic duct whose leakage, particularly in these cases, creates a favourable condition to hematoma and/or lymphocele formation. These complications, although rarely jeopardize patient's life, however, may affect the outcome of transplantation in terms of morbidity and survival of the organ. The use of ultrasonic scalpel ensures total control of vascular and lymphatic compartment coagulation, alongside a reduction in the time of surgical dissection.

A simple method to treat post-kydney transplantation lymphocele

To describe our experience with ultrasonic-guided instillation of povidone-iodine to treat post-kidney transplantation lymphocele. Patients and methods. We studied the safety and efficacy of this procedure for treatment of lymphocele in 6 male kidney transplanted recipients in which we assisted a progressive increase of creatinine and urinary proteins levels and color-Doppler ultrasonography demonstrated an increase (25,4%) of index of resistence (IR) Using eco-colorDoppler, the related-graft lymphocele location and the distance to the anterior abdominal wall were determined; then, a radiopaque double-lumen catheter was used to instillate 5% povidone-iodine 10 ml. Results. Percutaneous drainage achieved a resolution rate of 100%. Studying the rate of peripheral and internal vascularization of the kidney before and after treatment, eco-colorDoppler showed a significant decrease of the IR (24,6%). Conclusions. The US-guided povidone-iodine instillation for treatment of lymphocele following renal transplantation may be considered as first choice therapy in such disease.

Use of intraperitoneal ePTFE Gore dual-mesh plus in a giant incisional hernia after kidney transplantation: a case report

We evaluated the incidence of and predisposing factors for an incisional hernia after kidney transplantation. Numerous techniques have been used to repair postoperative fascial dehiscences or simple incisional hernias, but no clear treatment exists for giant hernias. Our aim was to obtain (1) a safe procedure to repair a large abdominal defect and reinforce the surrounding, fragile zones and (2) a simple, rapid technique to reduce the operative time. Herein we have described the surgical repair of a giant incisional hernia using intraperitoneal Gore ePTFE dual-mesh plus (Gore-Tex; W. L. Gore, Flagstaff, Ariz, USA) in a 55-year-old man status-post renal transplantation. Total necrosis of distal graft ureter had caused a giant urinoma. The patient was reexplored on day 2 posttransplantation with a primary fascial approximation. Thirty days after transplantation we discovered a large incisional hernia and performed a repair. No drain was used. The patient continued immunosuppressive therapy (cyclosporine, mycophenolate mofetil, prednisolone) and was discharged on postoperative day 4 with no complications. An ultrasonographic follow-up at 1 year revealed the prosthesis to be correctly positioned. Incisional hernia is not rare after renal transplantation but the real incidence is unknown. Immunosuppressive therapy, prolonged pretransplantation dialysis, obesity, and diabetes are probably the major causes of incisional hernias in these patients. Surgical complications of renal transplantation surgery, such as wound hematoma, urinoma, and lymphocele, are the most important predisposing factors for an incisional hernia. The use of intraperitoneal ePTFE dual-mesh is feasible, safe, and easy to repair a large incisional hernia in a kidney transplant patient.

Use of monitoring intraoperative parathyroid hormone during parathyroidectomy in patients on waiting list for renal transplantation

This report describes the use of intraoperative parathyroid hormone (ioPTH) assay during parathyroidectomy for patients with secondary hyperparathyroidism on the waiting list for renal transplantation. The levels of ioPTH were determined among waiting list patients undergoing subtotal parathyroidectomy and tertiary hyperparathyroidism patients undergoing procedures. The levels of ioPTH were significantly reduced at 10 minutes by 59.7,3% among with secondary hyperparathyroidism and 68.9% among tertiary hyperparathyroidism. A 15 minutes it was 85% in secondary hyperparathyroidism and 89.7% in tertiary hyperparathyroidism. A decrement of 50% in basal values at 10 minutes and 85% decrement or more at 15 minutes was predictive for the success of abnormal parathyroid gland removal. The application of this technique during subtotal parathyroidectomy results was useful to predict a correct excision of abnormal parathyroid glands among patients with secondary hyperparathyroidism on the waiting list and for tertiary hyperparathyroidism patients.

Successful treatment of gastrointestinal bleeding with recombinant factor VIIa after kidney transplantation in patients with pancytopenia

Hemostatic disorders can often complicate transplantation procedures. Moreover, antihemmorhagic drugs may not efficiently control bleeding that occurs in such cases. We report on a patient who underwent kidney transplantation complicated by bone marrow aplasia and gastric bleeding who was successfully treated with recombinant activated FVII (Novoseven). In May 2005, a 53-year-old man affected by chronic renal insufficiency underwent kidney transplantation. At the beginning of June, laboratory tests showed progressive reduction in the blood cell count with anemia, granulocytopenia, and thrombocytopenia related to the development of marrow insufficiency. We commenced transfusion therapy and administered hematologic growth factors. On June 3, 2005, the patient underwent surgical procedure to repair the abdominal wall. Two days thereafter, the postsurgical period was complicated by an episode of melena. The patient received additional treatment with packed red cells, platelets, and fresh-frozen plasma. The gastrointestinal bleeding continued until June 9, 2005, when therapy with recombinant activated FVII (Novoseven) was commenced at an initial dose of 90 microgr/kg. The first bolus did not significantly reduce the blood loss; it was therefore administered as a successive bolus at the same dosage that was able to stop bleeding. Endoscopic examination performed the day after showed the absence of the hemorrhagic lesion in the gastric mucosa. In the subsequent days, the need for transfusion was dramatically reduced with no episode of bleeding. At the same time, the laboratory and clinical findings of marrow insufficiency disappeared. Our case report showed that the use of a global antihemorrhagic factor, such as Novoseven, can successfully control gastrointestinal bleeding even in complicated patients despite failure of traditional antihemostatic therapy.

PTFE Mesh in Renal Allograft Compartment Syndrome

We report a case of anuria in a 42-year-old female kidney transplant patient that occurred secondary to extrinsic compression from a large kidney being placed extraperitoneally in a small iliac fossa. Prompt reexploration in the immediate postoperative period resulted in salvage of the graft with restoration of kidney function. The abdominal wall was reconstructed using prosthetic mesh, which decreased the compartment pressure within the iliac fossa sufficiently to allow the renal vein patency and the kidney perfusion. We think that this tension-free surgical technique should be applied in those cases in which the retroperitoneal space is less than the size of the kidney to avoid renal allograft compartment syndrome or incisional hernia.

Intraoperative Parathyroid Hormone Monitoring During Parathyroidectomy for Hyperparathyroidism in Waiting List and Kidney Transplant Patients

This report describes the use of the intraoperative parathyroid hormone (ioPTH) assay during parathyroidectomy in waiting list and transplanted patients. ioPTH levels were determined in 40 patients on the waiting list for kidney transplantation with secondary hyperparathyroidism who underwent subtotal parathyroidectomy and 9 transplanted patients with tertiary hyperparathyroidism who underwent removal of hyperplasic glands. Rapid PTH levels decreased significantly at each time period; the percentage decrease in rapid PTH levels was 61.3% among patients with IPT II and 70.2% in patients with IPT III at 10 minutes and 86.5% in patients with IPT II and 91% in patients with IPT III at 15 minutes after excision of hypersecreting parathyroid tissue. A decrease of 50% or more from baseline PTH levels at 10 minutes and/or a decrease of 85% or more at 15 minutes predicted successful removal of abnormal parathyroid glands. The application of this technique during subtotal parathyroidectomy has proved useful for correct excision of parathyroid glands among waiting list patients with IPT II, while in kidney transplant patients with IPT III it allowed removal of only the pathological glands with a limited surgical approach.

Use of Marginal Donors in Kidney Transplantation: Our Experience

The use of elderly donors has been advocated to expand the organ donor pool because of increased needs and the organ shortage. The aim of this study was to analyze whether the use of elderly donors and marginal kidneys affected the outcome of renal transplantations. Herein we presented data on 126 kidney transplantations performed from January 1996 to September 2003 using 32 marginal donors (group A) and 94 ideal donors (group B). We analyzed the medical and surgical complications and the graft survivals at a median follow-up of 18 months. Medical and surgical complications occurred in 22% and 5% versus 7% and 4% in groups A and B, respectively. The mean cold ischemia time and the mean age were greater for patients undergoing kidney transplantations from marginal donors. No differences were observed in graft survival in groups A and B. In conclusion, our data suggested that with an appropriate strategy and a correct selection of patients, marginal kidneys can be safely used to decrease the gap between demand and supply.

[Harvesting of the rat pancreas with in-situ perfusion. A microsurgical technic]

One of the principal obstacles to pancreatic islet transplantation is the poor yield of islet from donor pancreas. Many techniques have been designed to increase the yield of islets. The influence of pancreas harvesting technique on islet isolation and function has received little attention. The authors report their experience about pancreas procurement in the rat using a multiorgan harvesting technique according to the original methods of Starzl in the human cadaver donors with in situ liver and pancreas flushing with U.W. solution. Sixty adult male Wistar rats weighting 100 gr. on average entered into our studies and underwent to different techniques of pancreas procurement. Our results demonstrate that the microsurgical multiorgan retrieval technique with in situ U.W. flushing via common iliac artery allows the best islets recovery with a larger number and more vital cells compared with the traditional exanguinatio technique, though it is more expensive and time consuming.

Renal hydatidosis. Discussion of a clinical case complicated by post acute pancreatitic cyst

In this paper the authors describes a rare case of renal hydatidosis complicated by post acute pancreatitic cyst. There have been no reports up till now either of any physiopathological between the development of hydatid cysts in the vicinity of the pancreas and subsequent pancreatitis, or of any correlation between long-term albendazole therapy and acute pancreatitis. In our particular case, however, the volumetric increase of the renal cyst caused external compression of the pancreas and the consequent slowing-down of bilio-pancreatic flow, which probably led to the development of acute pancreatitis. Since, in our opinion, the pancreatic pseudocyst required surgical removal, we decided to perform the operation there and then; intraoperative examination of the cystic fluid and the presence of daughter cysts confirmed the suspected diagnosis of hydatidosis, of clear renal origin since it was closely attached to the upper pole and continued along the upper calyces renales; the cyst was easily detached from the lower and posterior edge of the liver, and was completely removed, together with its pericystium, which was detached from the lower surface of the liver and from the inferior subhepatic vein; only a tiny disk of pericystium was left in communication with a calyx, sutured to the rest of the kidney. The pancreatic cyst was drained by means of a mesocolic Roux-loop cysto-jejunostomy.

[Pancreatic harvesting from multiorgan donors for islet transplantation]

The result of human islet isolation procedures to transplant in type I insulin-dependent diabetic patients is significantly conditioned by the technique used for pancreas procurement from multiorgan donor. In fact, during multiorgan procurement, an improper handling of the gland could result in edema or degranulation of the acinar tissue, detrimental for the islet purification step. The surgical technique used by our surgical team, includes some important refinements to obtain the largest quantity and the best quality of purified endocrine material.

[Biologic activity of prostacyclin in patients with malignant tumors of the bones and soft tissues]

Hemostatic diffusion is mediated in part by platelet activation. Prostacyclin (PGI2) is known to be a powerful inhibitor of the aggregation of human platelets in vitro. In this study exogenous PGI2 was incubated in plasma of patients with bone and soft tissue cancer and its inhibiting activity of platelet aggregation was evaluated. Inhibition was found to be significantly lower and of shorter duration in the plasma of the 10 cancer patients tested as compared to the activity in the plasma of the healthy controls. Mechanisms of decreased prostacyclin activity are discussed in relation to the platelets in tumor cell metastases.