Early Enteral Nutrition in the Postoperative Period Following Pancreaticoduodenal Resection

The dissertation is dedicated to the study of the influence of early enteral nutrition on the course of the postoperative period and the direct treatment outcomes of patients after pancreaticoduodenal resection. Pancreaticoduodenal resection remains the primary operation for malignant tumors of the periampullary zone; however, the early postoperative period is characterized by progressive protein deficiency, increased catabolism, and significant fluid losses. The work justifies the application of enteral nutrition from the first days after surgery as a safe and no less effective method compared to parenteral nutrition, demonstrating its positive impact on the restoration of gastrointestinal tract function, immune status, and the reduction of postoperative complication frequency.

The investigation contains a pathogenetic justification for the inclusion of enteral nutrition in the complex of therapeutic measures, and a corresponding clinical protocol has been developed and tested. The materials of the dissertation have been implemented in the practical activities of the Department of Surgery of the Liver, Bile Ducts, and Pancreas of the Russian National Research Center of Surgery named after Academician B.V. Petrovsky. The scientific novelty consists in proving the necessity of preoperative nutritional preparation and early enteral nutrition in the postoperative period, as well as in substantiating the reduction of oxidative stress and the normalization of the immune system upon application of this method.

Pancreaticoduodenal resection is the primary operation for periampullary zone cancer: malignant tumors originating from the head of the pancreas, the major duodenal papilla, the duodenum, and the terminal portion of the common bile duct [Patyutko Yu.I., 1998; Garin A.M., 2000; Felekouras E., 2004; Emick D.M., 2006;]. In recent years, the refinement of pancreaticoduodenal resection technique, anesthetic support, and intensive care methods in the postoperative period have made it possible to reduce postoperative mortality after this operation to 1-7% in chronic pancreatitis [Kubyshkin V.A., 1998; Kasumyan S.A., 2003; Liao Q., 2002] and to 3-8% in periampullary zone cancer [Skipenko O.G., 2002; Mack L.A., 2004; Niedergethmann M., 2006]. Unfortunately, taking into account the late stages at the time of surgery and the aggressiveness of these tumors, the long-term results of such surgical interventions over the past 5-7 years in the best pancreatic centers amount to 15-25% [Gianotti L., 1999; Goonetilleke K.S., 2006].

If over the past 50 years since the appearance of the first works by Wipple (1935), Child (1948), Orr (1952) the question of improving the immediate results of PD resection has been raised, then in recent decades an increasing number of works have been devoted to the functional adaptation of the gastrointestinal tract in patients who have undergone PD resection [Diener M.K., 2007; Di Carlo V., 1999; Ishikawa O., 1996].

The result of these searches was a new organ-preserving variant of PD resection proposed by Traverso and Longmair (1978), which provides improved digestion after PD resection. This method preserves the stomach, the pyloric antrum, and the proximal portion of the duodenum.

The early postoperative period in patients after PD resection is characterized by progressive protein deficiency due to increased catabolism, traumatic surgical manipulations, significant fluid losses through drains from the abdominal cavity and stomach, and incomplete nutrient supply during replacement therapy [Gouma D.J., 2000; Hayashibe A., 2007].

The duration of postoperative gastroparesis, in the opinion of some authors, can reach 8 to 18 days [Kasumyan S.A., 2003; Fabre J.M., 1999; Goei T.N., 2001; Lermite E., 2007], which excludes the possibility of early normal nutrition in the postoperative period in patients after PD resection. This leads to delayed tissue regeneration of the pancreas, atrophy of islet cells, reduced intestinal absorption, and the development of postoperative complications. Therefore, in the early postoperative period, it is necessary to compensate for water-electrolyte, energy, and protein losses through the administration of parenteral nutrition [Asrarov A.A., 1996; Vretlin A., 1990; Lyashchenko Yu.N., 1987; Senkal M., 2004; Stig Bengmark et al., 2003].

Parenteral nutrition ensures functional rest of the pancreas throughout the postoperative period. The ease of introducing nutrient solutions into the vascular bed and the growing availability of various preparations ensure the wide application of the method. However, parenteral nutrition (PN) is associated with a large number of potentially dangerous complications related to the prolonged presence of a catheter in the central vein. The cost of PN preparations is 3-10 times higher than enteral diets [Luft V.M., 2003; Lyashchenko Yu.N., 1987; Khoroshilov I.E., 1998; Brennan M.F., 1994; Braunschweig S., 2001; Finck S., 2000].

According to D.V. Vyanskutonis et al. (1990), the absorptive capacity of the jejunum by the D-xylose test in abdominal patients reaches the baseline level already within one day after surgery. It should be noted that EN ensures functional rest of the pancreas, since the exclusion of nutrients from duodenal passage during EN reduces entero-pancreatic stimulation, gastrin release, hydrochloric acid secretion, and consequently the release of secretin and cholecystokinin, which enhance the hydrokinetic function of the pancreas and bile formation [Galperin Yu.M., 1982; Eramishantsev A.K., 1994; Maistrenko N.A., 1996; Ordukhanyan Z.S., 2002].

A number of studies have demonstrated that the use of EN in the postoperative period contributes to the rapid elimination of intestinal paralysis, early activation of intestinal motility, improved mucosal regeneration, and early activation of absorptive function of the distal intestinal segments. At the same time, the possibility of preventing excessive microbial contamination of the GI tract, the prophylactic effect of EN in relation to acute erosive-ulcerative lesions, the attenuation of the catabolic direction of metabolism, the normalization of immune status, the reduction in the number of infectious complications, and the shortening of the patients' hospital stay have also been noted [Bakhman A.D., 2001; Shcherbakova G.N., 1996; Kostychenko A.D., 2001; Gramlich L., 2004; Mertes N., 2000; Komplan L., 1999].

The problem of eliminating metabolic disorders and correcting protein-energy deficiency in the early postoperative period in patients operated on organs of the gastrointestinal tract has been given significant attention in recent times. In large multidisciplinary hospitals in the United States and Western Europe, attending physician teams provide therapeutic artificial nutrition to patients using parenteral and enteral nutrition preparations [Khoroshilov I.E., 2000; Popova T.S., 2002; Shevchenko B.F., 2002; Adams S., 1986; DeLegge M., 2001; Nicola W., 2003; Klein S., 1994; Marik P.E., 2004; LynH., 2003].

The traditional solution to this problem is achieved through infusion therapy, directed at the first stage at eliminating hemodynamic disorders and correcting gas homeostasis. At the second stage, the activity of the catabolic reaction of the body is reduced, energy expenditures are replenished, and the volume of transfusion therapy is supplemented with the use of EN formulations [Vander K.A., 1999; Lyashchenko Yu.N., 2001; Tsatsanidi K.N., 1987; Leiderman I.N., 2003; Jimenez L.L., 2004; Jolliet P., 1999; Lewis S.J., 2001].

At present, the protocols and algorithms for the application of EN in the early postoperative period in patients with pancreatic and periampullary zone pathology are not fully developed.

Thus, further investigation of various aspects of the application of enteral nutrition in the early period after pancreatic operations remains an urgent problem.

In connection with the above, the aim of this work was to study the influence of early enteral nutrition on the course of the postoperative period and the direct treatment outcomes of patients after pancreaticoduodenal resection.

In accordance with the main goal of the investigation, the following tasks were set:

1 To study the state of nutritional status in patients with diseases of the pancreas and periampullary zone at admission to the hospital and in dynamics under the influence of enteral nutrition in the early postoperative period.

2 To conduct a comparative evaluation of the clinical condition of patients according to the severity of clinical condition scale (SAPS) after pancreaticoduodenal resection with the administration of parenteral and enteral nutrition.

3 To investigate the dynamics of immune status in the postoperative period in patients who received enteral nutrition.

4 To evaluate the influence of enteral nutrition on the clinical course of the early postoperative period after PD resection.

Scientific novelty.

The work provides a pathogenetic justification for the inclusion of enteral nutrition in the complex of therapeutic measures for patients with diseases of the pancreas and periampullary zone after pancreaticoduodenal resection. It has been demonstrated that these patients require preoperative nutritional preparation and enteral nutrition in the postoperative period. Clinical and laboratory effects of the use of enteral nutrition in such patients have been demonstrated: reduction in the intensity of free radical oxidation processes, increase in the activity of antioxidant enzymes, normalization of patients' immune status.

It has been established that the use of enteral nutrition from the first days after pancreaticoduodenal resection is safe and no less effective than the application of total parenteral nutrition. At the same time, the normalization of general condition and immune system function in the postoperative period manifests itself through a reduction in the frequency of complications, a shortening of the recovery period of gastrointestinal tract functional activity, and a decrease in the duration of patients' hospital stay.

Practical significance

The algorithm for enteral nutrition developed and tested in the work makes it possible to improve the treatment outcomes of patients with periampullary zone pathology and reduce the duration of inpatient surgical treatment. In a comparative evaluation of the effectiveness of parenteral and enteral treatment, the advantages of the latter method and its clinical effectiveness have been demonstrated: a shortening of the recovery period of gastrointestinal tract functional activity has been achieved, and a reduction in the number and severity of complications has been attained. It has been scientifically substantiated that in the complex of preoperative examination of patients with periampullary zone pathology, it is necessary to provide for an assessment of the degree of nutritional deficiency. It has been demonstrated that enteral nutrition should be an obligatory component of the complex of measures after pancreaticoduodenal resection and an essential constituent part of etiopathogenetic treatment in the postoperative period, contributing to the reduction of oxidative stress and the normalization of immune system function. Recommendations have been given on the technique of performing early enteral nutrition, the calculation of volumes and durations of enteral nutrition application in the complex of postoperative treatment of such patients.

The materials of the dissertation have been implemented in the practical activities of the Department of Surgery of the Liver, Bile Ducts, and Pancreas of the Russian National Research Center of Surgery named after Academician B.V. Petrovsky.

Dissertation defense

The main provisions and results of the conducted research were reported at 3 international congresses "Parenteral and Enteral Nutrition".

Publications. Ten scientific works have been published on the dissertation topic: 2 articles and 8 abstracts.

Structure of the dissertation.

The dissertation consists of an introduction, 3 chapters, a discussion of results, a conclusion, conclusions, practical recommendations, and a list of references. The latter includes 54 domestic and 110 foreign sources.