Chronic Kidney Disease

Chronic renal failure is a disease, characterized by a glomerular filtration rate (GFR) below 60 ml/min per 1.73m2 for three months or more [1]. The registries of developed countries show an annual evolution of the incidence of chronic renal failure between 6 and 8 % [2].  When reached, ESRD requires the use of substitution treatment is inevitable. Currently, this treatment is classified under three main modalities: hemodialysis, peritoneal dialysis and transplantation [3]. Hemodialysis, generally used throughout the world. It is a technique that purifies the blood of excess water and uremic toxins. It was used for the first time by Wilhem Kolff for the treatment of patients with acute renal injury. As well as, the rotary drum dialyzer, created by Kolff, is a device operated for large-scale clinical use in the 1960s. The table above summarized the different stages of development of dialysis treatment of uremia [4].

TABLE I DIFFERENT STAGES OF DEVELOPMENT OF THE UREMIA TREATMENT

In 1913

The first attempt to produce a dialyzer designed for human use was made by John J. Abel. Its device consists of a series of 40 cm colloidal tubes.

In 1924

The first clinical trial of dialysis is executed by Dr. Georg Hass, working with patient with kidney failure was connected for 15 minutes. Despite the successful extraction of urine, it couldn’t replace renal function because of the blood coagulation.

In 1944

The creation of the drum dialyzer and the use of heparin as an anticoagulant by Dr. Willem Kolff, ensures the success of a first renal replacement therapy.

In 1955

The Drs. Gordon Murray, Edmund Delorme, and Newell Thomas have developed a double-coil dialyzer. Each time, the dialysis session is performed by the latter. There is the appearance of new arterial and venous blood lines placed.

In 1950

Belding Scribner used Teflon to create a shunte, which allows regular arteriovenous access.

In 1960

A first successful treatment that ensured the survival of a uremic patient for eleven years, in order of one to two sessions per week.

In 1961

The creation of the hollow fiber dialyzer. This tubule configuration has allowed for a larger effective area in a smaller package.   After the synthesis of the hollow fiber dialyzer, the main improvements were mainly in accessories such as the addition of performance monitoring tools like ionic dialysance or modules to monitor blood volume to almost all generators. During dialysis, the patient\’s blood is pumped from a vascular access through plastic pipes to the dialyzer, a semi-permeable membrane that transfers small and medium molecular weight solutions into the dialysate on the other side of the membrane, and then to other pipes before leading it to the vascular approach [5]. During the dialysis session, the dialyzer must be continuously fed by the dialysate, a liquid that is brought into contact with the blood through the dialyzer. This liquid is a mixture of ultra-pure water and electrolytes added in a fixed ratio [6]. The duration of dialysis treatment is usually 3-4 hours, 3 times a week. Generally, these sessions take place with very high blood flow rates (Qs) and dialysate flow rates in the order of 300 ml /min, for maximum exploitation of the expensive equipment (fig) [5].   Figure : Schematic representation of the hemodialysis purification circuit  Currently, dialysis has become a standard treatment for chronic kidney disease. Although it ensures the survival of more than one million people with chronic kidney disease worldwide. The delicate quality of life of dialysis patients due to nutritional restrictions, intensive treatment sessions at the centre and high rates of cardiovascular morbidity and mortality make it an imperfect treatment. And, its disastrous ecological and financial impact. From an ecological point of view, Switzerland characterizes the energy and ecological impact of hemodialysis by expressing it in the form of a quantitative analysis of the consumption of electricity, water and the production of non-recyclable waste by the Lausanne Nephrology Service. Hemodialysis is a very sophisticated and highly accurate technique. It requires special equipments and highly qualified personnel. In Morocco, each hemodialysis session costs 77.18 €, including other fees. Direct costs represent the major part by 778.91 dirhams (91.6%), of which the cost of the consumable dominates by 44.93%. The indirect cost represents 6.23% of the total cost. In year/patient units, the cost of hemodialysis is 12,040.31 Euros [8]. In order to improve the quality of life of dialysis patients and reduce the ecological and financial impact of dialysis at the centre, the Engineering and Biomedical research team has set itself the objective of creating the MorWAK device, which is patented under number WO2016/072826A1. The MorWAK system is a complex mix of mechanical, electrical, electronic and hydraulic components that puts the patient\’s life at risk at all times. Strict technical safety standards are maintained to protect the users from any risk inherent in the use of the MorWAK. The development of portable technologies and the use of Information and communications technology (ICT) have made it possible to monitor blood and venous pressure in order to ensure the control and integrity of the extracorporeal circuit. Particular attention is given to the monitoring of extracorporeal blood circulation in the definition of the alarm ranges planned for arterial and venous circuits. The slightest pressure difference must be detected to avoid the risk of haemolysis and haemorrhagic damage. A gyroscopic air detector is provided to avoid any gas embolism in the event of accidental disconnection. A Human Machine Interface (HMI) allows the permanent in the real-time display the parameters. The monitored and configuration can be made in the site or remote  of the MorWAK in order to customize the treatment. The first prototype is made and tested on bags of complete bovine blood and made it possible to model the extraction of the liquid according to the pressures on either side of the semi-permeable membrane and the volumes allowed by the suction bellows. The ICTs used in this way allow the real-time plotting of curves representing the parameters to be monitored, namely, blood pressure, venous pressure and the evolution of the volume of liquid extracted. The MorWAK thus operates without dialysate [9]. The MorWAK device will be transportable, simply handling and guarantees total patient safety. The following table provides a comparative study between MorWAK and the current system.

Leave a Reply

Your email address will not be published. Required fields are marked *