Pancreas transplantation

Pancreas transplantation is a form of replacement of pancreatic p-cells, which allows to restore the normal blood sugar level - normoglycemia - in diabetic patients. Since recipients change the need for insulin injections to take immunosuppressants, pancreas transplantation is performed primarily for patients with type 1 diabetes with renal insufficiency, and who are thus candidates for kidney transplantation; About 90% of pancreas transplantations are performed together with kidney transplantation. In many centers, the criteria for choosing this method of treatment are also the lack of standard treatment and cases of unexplained hypoglycemia. Relative contraindications are age over 55 years, serious cardiovascular atherosclerotic diseases, a history of myocardial infarction, a surgical coronary artery graft, transcutaneous coronary interventions, or a positive stress test; these factors significantly increase perioperative risk.

Pancreas transplantation includes simultaneous transplantation of the pancreas and kidneys (SPK - simultaneous pancreas-kidney), pancreas-after-kidney transplantation of the pancreas (kidney cancer), transplantation of one pancreas. The advantages of SPK are the simultaneous exposure of immunosuppressants to both organs at once, the potential protection of the transplanted kidney from the adverse effects of hyperglycemia and the ability to control kidney rejection; Kidneys are more prone to rejection than pancreas, whose rejection is difficult to track. Advantage of CANCER is the ability to optimize the selection of HLA and the timing of kidney transplantation when using a living donor organ. Pancreas transplantation is used mainly for patients who do not have terminal stage of kidney disease, but who have serious complications of diabetes, including insufficient control of blood glucose levels.

Donors are recently deceased patients aged 10-55 years who have no history of intolerance to glucose and who have not abused alcohol. For SPK, the pancreas and kidneys are taken from the same donor, the restrictions for organ harvesting are the same as for kidney donation. A small number (<1%) of segmental transplants from live donors is carried out, but such a procedure carries a significant risk to the donor (eg, spleen infarction, abscess, pancreatitis, pancreatic juice and pseudocyst infection, secondary diabetes), which limits its widespread use.

By now, the total two-year survival of pancreatic pancreatic transplants reaches 83%. The main criterion of success is the optimal functional state of the organ transplantation, and secondary criteria are the age criteria of donors older than 45-50 years and general hemodynamic instability. The experience of transplanting a part of the pancreas from a living related donor is also quite optimistic. The annual survival rate of the transplant is 68%, the 10-year survival rate is 38%.

However, the best results of pancreas transplantation in patients with diabetic nephropathy were obtained with simultaneous transplantation of the kidney and pancreas.

Peculiarities of anesthetic support for pancreas transplantation are generally characteristic of this category of endocrinological patients. Pancreas transplantation is usually indicated for diabetic patients with the most severe, rapidly progressing course of the disease and complications.

[1], [2], [3], [4], [5], [6]

Anatomico-physiological features of the pancreas and pathophysiological changes with insufficient function

The serious condition of patients with diabetes mellitus, which shows pancreas transplantation, is due to acute or chronic insulin deficiency. Acute insulin deficiency causes the development of rapid decompensation of carbohydrate and other metabolic forms and is accompanied by a diabetic symptom complex in the form of hyperglycemia, glucosuria, polydipsia, weight loss along with hyperphagia, ketoacidosis. Sufficiently prolonged course of diabetes leads to systemic vascular damage - diabetic microangiopathy. Specific damage to the retinal vessels - diabetic retinopathy is characterized by the development of microaneurysms, hemorrhages and proliferation of endothelial cells.

Diabetic nephropathy is manifested by proteinuria, hypertension with subsequent development of chronic renal failure.

Diabetic neuropathy is a specific lesion of the nervous system that can manifest itself in a symmetrical multiple lesion of the peripheral nerves, the lesion of one or more nerve trunks, the development of the diabetic foot syndrome, the formation of trophic ulcers of the legs and feet.

Due to a decrease in immunity in patients with diabetes, a large number of concomitant diseases often occur: frequent acute respiratory infections, pneumonia, infectious diseases of the kidneys and urinary tract. There is a decrease in the exocrine function of the stomach, intestines, pancreas, hypotension and hypokinesia of the gallbladder, constipation. Often there is a decline in fertility in young women and impaired growth in children.

[7], [8]

Preoperative preparation and assessment of the patient's condition before surgery

Preoperative examination includes a thorough examination of the organs and systems most affected by diabetes. It is important to identify the presence of signs of IHD, peripheral neuropathy, the degree of nephropathy and retinopathy. The stiffness of the joints can make it difficult to perform laryngoscopy and intubation of the trachea. The presence of vagal neuropathy may indicate a slowdown in the evacuation of solid food from the stomach.

Before the operation, such patients undergo biochemical tests, including a test for glucose tolerance; determination of C-peptide level in urine and plasma, determination of blood glucose (glycemic control index for previous months) and insulin antibodies to islet cells. To exclude cholelithiasis, ultrasound of the gallbladder is performed.

In addition to the constant preoperative control of the plasma glucose level, mechanical and antimicrobial intestinal preparation is usually undertaken.

Premedication

The scheme of premedication does not differ from that in the transplantation of other organs.

Basic methods of anesthesia

When choosing the method of anesthesia, preference is given to OA, combined with prolonged EA. RAA provides adequate postoperative analgesia, early activation of patients, significantly fewer postoperative complications. Induction of anesthesia:

Midazolam IV 5-10 mg, once

+

Heckobarbital iv in 3-5 mg / kg, once or Thiopental sodium IV iv 3-5 mg / kg, once

+

Fentanyl IV 3.5-4 μg / kg, once or Propofol iv at 2 mg / kg, once

+

Fentanyl IV 3.5-4 μg / kg, once.

Muscle relaxation:

Atracuria besylate IV 25-50 mg (0.4-0.7 mg / kg), once or Pipecuronium bromide IV 4-6 mg (0.07-0.09 mg / kg), once or Cisatracurium bezylate in / in 10-15mg (0.15-0.3 mg / kg), once. Maintenance of anesthesia: (general balanced anesthesia based on isoflurane)

Isoflurane inhalation 0.6-2 MAK I (in the minimal-flow mode)

+

Dinitrogen oxide with oxygen inhalation (0.3: 0.2 l / min)

+

Fentanyl IV bolusno 0,1-0,2 mg, the frequency of administration is determined by the clinical feasibility

+

Midazolam IV bolus 0.5-1 mg, the frequency of administration is determined by the clinical feasibility or (TBVA) Propofol iv / 1.2-3 mg / kg / h, the frequency of administration is determined by the clinical feasibility

+

Fentanyl 4-7 μg / kg / h, the periodicity of administration is determined by clinical feasibility or (general combined anesthesia based on prolonged epidural blockade) Lidocaine 2% rr, epidural 2.5-4 mg / kg / h

+

I Bupivacaine 0.5% rr, epidural 1-2 mg / kg / h Fentanyl / bolusno 0.1 mg, the periodicity of administration is determined by the clinical feasibility of Midazolam IV bolus 1 mg, the frequency of administration is determined by clinical feasibility. Muscle relaxation:

Atracuria besylate iv 1 - 1.5 mg / kg / h or Pipecuronium bromide iv 0.03-0.04 mg / kg / h or Cisatracurium bezylate iv 0.5-0.75 mg / kg / h.

[9], [10], [11], [12], [13]

Auxiliary therapy

One of the important conditions for survival of pancreas and kidney transplants is the maintenance of high CVP, equal to 15-20 mm Hg. Art. Therefore, it is important to conduct correct infusion therapy in which the main components of the colloidal component are 25% albumin solution, 10% HES solution and dextran with an average molecular weight of 30,000-40,000, and crystalloids (30 ml / kg) are administered as sodium chloride / calcium chloride / potassium chloride and 5% glucose with insulin:

Albumin, 10-20% r.p., in / in 1-2 ml / kg, the frequency of administration is determined by clinical feasibility or

Hydroxyethyl starch, 10% rr, iv 1-2 ml / kg, the periodicity of administration is determined by the clinical feasibility or

Dextran, the average molecular weight of 30 000-40 000 intravenously 1-2 ml / kg, the frequency of administration is determined by the clinical feasibility

Dextrose, 5% rr, iv 30 ml / kg, the frequency of administration is determined by clinical feasibility or

Sodium chloride / calcium chloride / potassium chloride in / in 30 ml / kg, the periodicity of administration is determined clinically

Insulin IV / 4-6 units, then the dose is selected individually.

Immediately before the removal of vascular clamps, 125 mg of methylprednisolone and 100 mg of furosemide are administered:

Methylprednisolone in / in 125 mg, once

+

Furosemide iv in 100 mg, once.

With the introduction of insulin in the preoperative period, the development of hypoglycemia should be avoided. Optimal is the level of mild hyperglycemia, which, if necessary, is corrected in the postoperative period.

Very important is intraoperative monitoring of plasma glucose. When correcting hyperglycemia during the operation, insulin is administered as a bolus, and as an infusion in a solution of 5% glucose.

Currently, most pancreas transplantations are performed using the technology of bladder drainage, which provides for its extraperitoneal placement.

[14], [15], [16], [17]

How is the transplantation of the pancreas?

The donor is anticoagulated, and a cold canning solution is introduced through the celiac artery. The pancreas is cooled in situ with ice cold saline, removed in a block with the liver (for transplantation to different recipients) and the second part of the duodenum containing the teats of the nipple.

The donor pancreas is located intraperitoneally and laterally in the lower abdominal cavity. In the case of SPK, the pancreas is located in the right lower quadrant of the abdominal cavity, and the kidney is in the lower left quadrant. Own pancreas remains in place. Anastomoses are formed between the donor splenic or superior mesenteric artery and the abdominal artery of the recipient and between the donor portal vein and the ileal vein of the recipient. Thus, the endocrine secretion systematically enters the bloodstream, leading to hyperinsulinemia; sometimes form an anastomosis between the pancreatic 1C venous system and the portal vein, V additionally to restore normal physiological state, although this procedure is more traumatic, and its advantages are not completely clear. The duodenum is sutured to the tip of the gallbladder or to the jejunum to drain the exocrine secretion.

The courses of immunosuppressive therapy are diverse, but usually include immunosuppressive lg, calcineurin inhibitors, purine synthesis inhibitors, glucocorticoids, the dose of which gradually decreases by the 12th month. Despite adequate immunosuppression, rejection develops in 60-80% of patients, initially hitting the exocrine, and not the endocrine apparatus. In comparison with transplantation, only kidneys in SPK have a higher risk of rejection and cases of rejection tend to develop later, recur more often and be resistant to glucocorticoid therapy. Symptoms and objective signs are not specific.

With SPK and CAN, rejection of the pancreas, diagnosed by increasing serum creatinine levels, almost always accompanies kidney rejection. After a pancreas-only transplant, a stable concentration of amylase in the urine in patients with normal urine outflow excludes rejection; its reduction suggests some forms of graft dysfunction, but not specific for rejection. Therefore, early diagnosis is difficult. The diagnosis is based on the data of cystoscopic transduodenal biopsy performed under the control of ultrasound. Treatment is carried out antitimotsitarnym globulin.

Early complications are noted in 10-15% of patients and include wound infection and divergence of seams, significant hematuria, intra-abdominal leakage of urine, reflux pancreatitis, recurrent urinary tract infections, small intestinal obstruction, abdominal abscess and transplant thrombosis. Late complications are associated with loss of urine of pancreatic NaHCO3, which leads to a decrease in the volume of circulating blood and metabolic acidosis without an anionic failure. Hyperinsulinemia, apparently, does not have a negative effect on the metabolism of glucose and lipids.

What is the prognosis of pancreas transplantation?

By the end of year 1, 78% of transplants and more than 90% of patients survive. It is not known whether the survival rate is higher in patients after a procedure such as pancreas transplantation compared to patients who did not undergo transplantation; but the main advantages of this procedure are the elimination of the need for insulin and the stabilization or improvement of many complications of diabetes (eg, nephropathy, neuropathy). Transplants survive in 95% of cases with SPK, in 74% - with RAK and in 76% - with transplantation only pancreas; it is assumed that survival after CAN and transplantation of only the pancreas is worse than after SPK, since there are no reliable rejection markers.

Correction of violations and assessment of the patient's condition after surgery

In the postoperative period, patients rarely require intensive therapy, although careful monitoring of plasma glucose and the use of insulin infusions are necessary. As soon as the diet resumes through the mouth, with the preserved function of the transplant, insulin administration becomes unnecessary. A great advantage of the technique of bladder drainage is the ability to control the exocrine function of the graft, which worsens during episodes of rejection. The pH of the urine may drop, reflecting a decrease in pancreatic bicarbonate secretion and a urine amylase level. The most frequent postoperative complications are transplant thrombosis and intraperitoneal infection.

[18], [19], [20]