Conceptual fundamentals of portosystemic shunting with integral assessment of life prognosis in patients with liver cirrhosis

Topicality and demand of the subject of dissertation. Currently, liver cirrhosis (LC) with portal hypertension (PH) is one of the leading causes of disability and mortality. In many countries, high viral hepatitis mortality rates and the growth of such LC etiological factors as alcoholism, toxic, and drug induced liver injuries raise this pathology to a higher degree of social significance.
The most severe and unpredictable complication of LC with PH is bleeding from esophageal and gastic varices, which is observed in 20-50% of patients. In addition, mortality rate from hemorrhagic syndrome reaches 30-80%. If hemostasis is achieved without the use of surgical methods, recurrence of haemorrhage develops in 50-70% of patients during a year and in 80-90% of patients - within the two-year of surveillance. It should be noted that 30% of patients with recurrent bleeding will be refractory to conservative treatment, and evident blood loss will cause abrupt hepatic decompensation.
Such high mortality rates cause the necessity of performing interventions aimed at preventing hemorrhagic syndrome, among which the most optimal are endovascular and surgical methods of portal system decompression.
In modern surgical hepatology, active introduction of minimally invasive techniques led to the decrease of interest in traditional portosystemic shunt (PSSh). This trend is also greatly affected by the widespread introduction of radical treatment of LC - liver transplantation.
However, the results of a number of foreign researches show that for patients with functional classes «А» and «В» (Child-Pugh) portosystemic shunting must be still considered as an optional method for preventing bleeding from esophageal and gastic varices, since by efficacy and survival rate vascular decompressive surgeries exceed other alternative traditional and minimally invasive techniques.
On the other hand, the lack of the threat of hemorrhagic syndrome, slow increase of functional liver failure, and often long-term stable course of diffusion process after portosystemic shunting allow not only to reduce the tension, while waiting for a donor liver, but also, within certain groups of patients, to remove the issue about the appropriateness of liver transplantation from the agenda.
From these positions, continuing scientific studies on key issues of surgical prophylaxis of variceal bleeding and improvement of portosystemic shunting results emphasize the relevance of this disscrtational research.
For the Republic of Uzbekistan, during the past years of independence, the development of PH surgery has become one of the priority directions, determined by the great social and medical significance of such an important issue as the treatment of LC. Cardinal changes in the healthcare system, which started in accordance with the Decree of the President of Uzbekistan № UP-2107 «State Program on Reforming the Healthcare System of the Republic of Uzbekistan» from November 11, 1998 and implementing a series of state programs, including «About main directions of further deepening of reforms and realization of State Program on healthcare development” (№ UP-3923, from September 19, 2007), at present allowed to achieve significant results in many scientific and practical fields of medicine. Among them, the improvement of surgical care quality of cirrhotic patients with PH has become one of the objective criteria of positive reforming results.
Observing principles of rigid scientific and practical competition in this field has allowed the RSCS named after acad. V.Vahidov to enter into the circle of the highest rated international surgical centers. It should be noted that at present the center is one of the world leaders in portosystemic shunting experience and achieved results. High level and significance of fiftccn-year cycle of scientific publications, devoted to this difficult section of hepatology, has received the highest appreciation, and in 2010, the CIS Association of Surgeons-hepatologists awarded it with the first prize of the «Annals of Surgical Hepatology» journal.
At the same time in the healthcare and health protection system, there are still many unresolved issues, associated with the increase of the prophylaxis level of complications in cirrhotic patients with PH and, in the first place, the quality of surgical care on the regional and district levels.
Modem systems of prognostic evaluation of the severity of diffuse process in the liver can seriously contribute to the development of this field. Their practical value encompasses a wide range of possibilities: from choosing radical treatment terms up to the dynamic assessment of pathological processes in the liver and objective analysis of the quality of the recommended treatment or performed surgical PH correction.
In this regard, the need to develop the concept of surgical treatment of PH in cirrhotic patients, with in-depth study of received data on the portosystemic shunting effectiveness, optimize the choice of decompression type, individual characteristics of the portal angioarchitectonics and prognostic significance of integrated assessment systems arc considered one of the important criteria of the demand for the dissertation theme.
Purpose of research is to develop the concept of surgical treatment of PH in patients with LC, which is based on the integrated system for assessing the risk of complications and prognostic quality of life analysis in patients after portosystemic shunting for determining the need and optimal timings for live donor liver transplantation.
The scientific novelty of the dissertational research consists of the following:
for the first time in the Republic of Uzbekistan the frequency of the development of variceal bleedings was defined; regions with the maximum rate of this complication were identified; and the spectrum of providing surgical treatment was analyzed;
defined the role of portosystemic shunting in modem PH surgery, its predictive value for LC patients, and competitive perspectives;
the classification of hemodynamic violations of portohepatic circulation in cirrhotic patients with PH, which allowed to optimize the degree of decompression of porto-licnal pool for preserving adequate level of hcpatopctal blood flow, was developed;
basic criteria for forecasting portosystemic shunting were scientifically proved and unified. Integrated programs for defining the severity of the status of LC patients, as well as the possibility for performing planned surgical prophylaxis of bleedings from esophageal and gastic varices, and assess the risk of portosystemic shunting complications, mortality and survival rates, were designed;
basic criteria for forecasting portosystemic shunting were scientifically proved and unified. Integrated programs for defining the severity of the status of LC patients, as well as the possibility for performing planned surgical prophylaxis of bleedings from esophageal and gastic varices, and assess the risk of portosystemic shunting complications, mortality and survival rates, were designed;
for the first time the assessment of the portosystemic shunting impact on the course and severity of the status of patients with LC, which have the risk of variceal bleeding, was conducted, using the MELD prognostic scale. The dynamics of this indicator in remote follow-up surveillance periods after portosystemic shunting was studied to verify survival prognosis and to assess the need for liver transplantation and the potential timing of its implementation;
for the first time, using the special CLDQ questionnaire (The Chronic Liver Disease Questionnaire), a quality of life analysis of patients with liver cirrhosis after portosystemic shunting was made. The impact of bypass surgeries on the dynamics of this indicator, which assesses health and postoperative characteristics, depending on the type of portal system decompression, was defined;
a new technique of the ligature dissociation of gastroesophageal collector on the wireframe prosthesis was developed. It is considered the most promising operational tool, when conducting planned interventions in patients with PH syndrome, which underwent re-operative treatment or it can become an alternative portosystemic shunting method, if the latter is impossible to perform.
CONCLUSION
1. In Uzbekistan, the average frequency rate of the development of bleeding from EGV is 7.9 per 100,000 people. In addition, in the structure of the total number of patients, the largest number of patients is from the Ferghana Valley -46.8% (13.1 per 100,000 people). 21.0% (8.4 per 100,000 people) came from Tashkent, Tashkent and Syrdarya regions; 15.5% (8.0 per 100,000 people) - from Samarkand and Jizzakh regions; 6.6% (3.1 per 100,000 people) - from Surkhandarya and Kashkadarya regions; 6.4% (5.7 per 100,000 people) - from Bukhara and Navoi regions; and 3.8% (2.7 per 100,000 people) - from Khorezm region and the Republic of Karakalpakstan.
2. The risk of the development of bleeding from EGV, against the background of progressing intrahcpatic block and growth of PH, depends on individual anthropometric data, hemodynamic features, and angioarchitccture of splenoportal channel, and averages 44.3%, while the lack of specific measures for preventing the hemorrhagic syndrome increases the probability of its relapse up to 86.7%.
4. Under progressive portal hypertension conditions, a classification of the hemodynamic violations of portohcpatic circulation in cirrhotic patients with PH may be based on defining its deficit, using the radionuclide scintigraphic method, and the blood flow inversion degree in the tributaries of the portal pool, according to digital dynamic splenoportography data.
5. The implementation of the standardized approach to diagnosing LC complications and the integrated program, determining the severity of patients’ status, allowed to improve, qualitatively, the primary score of the possibility to perform planned surgical prophylaxis of bleedings from EGV, reduce the frequency of overdiagnosis of the hemorrhagic syndrome risk from 12.0% to 7.0%, and level the frequency of contraindications to operations from 27.4% to 9,6% (P=0,003).
6. The integrated program of the PSSh risk assessment in cirrhotic patients, which was developed on the basis of a conceptual approach to generating a database with defining prognostically significant criteria, allows to calculate the risk of specific postshunting complications, mortality rate, and the survival prognosis with verified methodological accuracy: 85,6-98,3% - for selective shunting type and 88,0-98,9% - for central decompression types.
7. The most progressive deterioration of quality of life (CLDQ) of LC patients after PSSh occurs in the period between one and three years of surveillance (P <0.001). In addition, according to the physical state scale, within more than five years, this indicator, relatively to the control one, is only 55,5 ±
5.4% for selective decompression and 55,1 ± 5,9% - for central PSSh; on the scale of the psychological state and subjective perception of patients’ own health, the indicator is 49,2 ± 5,7% and 46,6 ± 5,3%, respectively. These data indicate progressing of a pathological process in the liver with possible development of decompensation.
8. The comparative assessment analysis of the mortality risk in cirrhotic patients showed that in the group of patients, whom PSSh was planned, the average value was 10,19±0,24 points on the MELD scale, and 7,13 ± 0,17 points on the Child-Pugh scale. This is reliably less than in patients with an absolute indication for liver transplantation - 19,56±0,69 points (P <0,001) and 11,56 ± 0,38 points (P <0,001), respectively.
9. PSSh does not lead to the reliable deterioration of the indicator on the MELD scale (10,19±0,24 vs. 10,94±0,23 points) in early postoperative period, but during the first year of surveillance, this value deteriorates to ll,79±0,32 points (P<0,05), and the survival rate reaches 90.6%. At the same time, during these periods the MELD score value above 15 points (an indication for liver transplantation), against the background of progressive liver pathological process, were defined only in 15.6% of patients.
10. In portal hypertension surgery, PSSh remains one of the optimal ways to prevent bleedings from EGV. The conceptual importance of this type of intervention is determined not only by limited ability to perform liver transplantation, but also by a competitive perspective to reduce the demand for radical interventions in patients with functionally compensated LC.
11 .Allying the developed diagnostic standards and the individual approach to choose an optimal variant of the portal system decompression allowed to reduce the frequency of postoperative liver failure from 18.8% to 9.1% after central PSSh and from 14.3% to 8.3% after selective decompression; the frequency of thrombosis of anastomosis from 8.9% to 2.7% after central PSSh and from 5.7% to 2.4% after selective one; and the frequency of mortality rate from 6.9% to 2.7% and from 8.6% to 3.9%, respectively.