ročník 8,2000 č.4

Editorial

Editorial

CHOLESTASIS AFTER LIVER TRANSPLANTATION: ETIOLOGY AND PATHOGENESIS

Eytan Mor, M.D.

Head, Liver Transplantation Unit
Rabin Medical Center, Beilinson Campus
Petah Tikva, Israel

Bile formation and excretion are important physiologic functions of hepatocytes, with cholestasis defined by impairment in bile flow. Many processes may lead to hepatic cell injury after liver transplantation, thus interfering with bile formation and excretion. Although the majority of such events remain subclinical, severe cholestasis may be associated with irreversible cellular damage to the liver, requiring retransplantation.
Cholestasis after liver transplantation is classified into two forms according to the site of the functional defect. Extrahepatic cholestasis is caused by obstruction of large bile ducts, whereas intrahepatic cholestasis is an impairment of bile excretion at the level of the hepatocytes or within the canaliculi (intrahepatic bile ductules) (1).
Bile excretion is an extremely useful marker of liver allograft function. The color, viscosity and the amount of bile change in correlation with the degree of cellular injury and cholestasis. In severe cholestasis there is minimal output of watery bright bile associated with acholic stools.
Generation of bile flow is an osmotic process driven by ATP-dependent secretion of solutes into the bile canalicular space between adjacent hepatocytes, followed by passive influx of water and electrolytes. Bile salts are responsible for the generation of bile-salt dependent bile flow (BSDF), which accounts for the majority of bile flow. The other fraction, bile-salt independent bile flow (BSIBF), comprises the combined action of all other bile constituents (1).
This review summarizes the various etiologies of cholestasis after liver transplantation and discusses their pathogenesis.

Intrahepatic Cholestasis

The various causes of intrahepatic cholestasis are shown in Table 1.

Table 1 : Etiologies for posttransplant cholestasis
Intrahepatic Cholestasis Extrahepatic Cholestasis
Ischemia-repaerfusion Anastomotic biliary stricture
Drug toxicity Non-anastomotic stricture/s
Systemic infection/sepsis Recurrent cholangitis
Chronic rejection Recurrent PSC
Recurrent disease (HCV) Mucocele
Vascular complications Cholangiocarcinoma
  Pancreatitis

The different mechanisms involved in each process lead to a common pathway in which bile flow is impaired and cholestasis develops. Although each process may induce cholestasis, many times a combination of these factors is present.

Ischemia reperfusion

Cholestasis may present early after transplant as a result of ischemic-reperfusion injury. This common phenomenon resolves spontaneously in most cases (2). In the more severe form, patients have associated injury to parenchymal and Kupffer's cells and high morbidity and mortality, mainly due to septic complications (3). Clinically, patients present with poor synthetic graft function associated with rising bilirubin levels.
Although liver biopsy shows only minimal changes immediately after reperfusion, biopsies performed a few days after transplant may show hepatocyte drop-out and ballooning degeneration in the central zone. Development of centrilubalar necrosis reflects a more severe degree of ischemic cellular damage. Signs of cholestasis generally appear after the first or second week posttransplant and include (in addition to the ballooning degeneration) formation of cholestatic liver cell rosettes, xanthomatous cells, bile stasis and progressive ductular reaction in the portal triads (4). Ultrastructural canalicular changes, however, have been described as early as 60 minutes after reperfusion, with increases in the mean area and perimeter of the canaliculus and with marked loss in the number of bile microvilli (2).
The proposed mechanism by which ischemic-reperfusion injury leads to cholestasis is via oxidative stress to the hepatocytes. The release of reactive oxygen species (ROS) leads to lipid peroxidation and oxidative changes of the cytoskeleton (5); as a result, the disruption of actin microfilaments associated with canalicular dilatation and loss of microvilli lead to reduced bile flow and cholestasis (2). Increased endotoxin levels in the portal vein during the anhepatic phase and the oxidative stress of ischemia-reperfusion also activate Kupffer's cells and induce the release of active cytokines (TNF-a and IL-1).
All transplant recipients show some degree of abnormal biochemical cholestatic parameters, with total bilirubin levels peaking around postoperative day 10 and gamma glutamyl transferase (GGT) peaking at day 14 (2). In most patients, these two biochemical cholestatic parameters normalize within another week or two. If total bilirubin, alkaline phosphatase and GGT remain high, with production of poor inspicated bile, and if extrahepatic obstruction has been ruled out, then the graft has most likely suffered irreversible preservation injury and the patient will require retransplantation.
Several risk factors for ischemic-reperfusion cholestasis deserve the clinician's attention. Cholestasis is more often seen with prolonged cold ischemia. Liver grafts from aged donors (>60 yr) are at particular risk (6). This is due both to lower levels of the intracellular energy stores necessary for the active transport system and to age-related changes of the cellular microstructure. Cholestasis has also been described in small-for-size segmental liver transplantation (7). When the graft-weight-to-patient-weight ratio is less than 0.6%, cholestasis is an almost universal finding, with a high risk for graft dysfunction and subsequent loss. Today, when living-donor transplants using segmental grafts for adult recipients are becoming common in major transplant centers, it is important to recognize this complication, although its pathogenesis remains unclear.

Drug-asssociated cholestasis

Several medications that are often used after transplant (e.g., azathioprine, amoxicillin, phenytoin and sulfonamides) may cause posttranspant cholestasis (Table 2).

Table 2: Drugs that Can Induce Cholestasis
Amoxicillin/clavulanic acid Imipramine
Atenolol Ketoconazole
Azathioprine Methimazole
Captopril Methylprednisolone
Chlorpropramide Nitrofurantoin
Chlorpromazine Phenylbutazone
Cyclosporine A Phenytoin
Danazole Prochlorperazine
Erythromycin Sulfonamides
Estrogens Thiabendazole
Floxuridine Tolazamide
Flurazepam Tolbutamide
Gold Trimethoprim-Sulfamethoxazole
Grisiofulvin Valproate
Haploperidol Warfarin

Among the immunosuppressive agents, azathioprine is most commonly associated with cholestasis. Other medications such as tacrolimus (FK506) and cyclosporine A (CyA) can also cause cholestasis. The mechanism for cholestasis-induced injury by these two agents has been studied in animal models. In rats, tacrolimus at high doses induced cholestasis by inhibiting primarily biliary excretion of glutathione, and to a lesser extent, bicarbonate, without altering bile acid secretion (8). In an isolated dually perfused rat model, liver hypoperfusion and cyclosporine A had a cumulative effect on the peribiliary capillary plexus (9). Nevertheless, in the clinical setting, hepatoxicity caused by cyclosporine A and tacrolimus usually occurs in association with toxic levels and in the presence of other side effects (e.g., nephrotoxicity, neurotoxicity, GI toxicity) (10). It is important, though, to remove any possible offending agent in patients with severe cholestasis after transplant.

Chronic infection/sepsis

Probably the most common cause of posttransplant cholestasis is chronic infection or sepsis. Synthesis of cytokines by Kupffer's cells (TNF a, IL-1 and IL-6) in response to release of endotoxin leads to impaired bile acid intake and secretion through modulation of the activity of bile acid and other organic anion transporters (11). At the molecular level, altered gene expression at the transcription level, with down-regulation of transporter proteins, has been reported (ntcp, mrp2) (12).
Septic complications are responsible for much of the morbidity and mortality that occurs during the first three months after liver transplantation. Severe preservation-reperfusion injury associated with cholestasis may precede the development of septic complications in these cases. Histological features of cholestasis similar to those described above are seen on liver biopsy, associated with increased levels of cholestatic enzymes. Recovery from sepsis-related cholestasis depends on the response to antimicrobial agents and the reserve of liver cell mass.

Chronic rejection

Bile duct injury is the hallmark of acute rejection. Although most episodes of acute rejection resolve with appropriate treatment, progressive bile duct destruction leading to chronic ductopenic rejection sometimes ensues. A major feature of chronic rejection is loss of bile ducts (>50%) within the portal tracts associated with biochemical evidence of cholestasis (elevated plasma levels of total bilirubin, alkaline phosphatase and GGT). The immune mechanisms of chronic rejection are undefined, but an important histological feature is the appearance of foam-cell arteritis with obliteration of end arteries supplying the periductular plexus (13). Cholestasis with accumulation of bile salts within the tissues may present clinically with severe pruritus.
Progressive ductular ectasia leading to chronic cholestasis has been reported in patients who received an ABO-incompatible liver allograft (14). Enhanced expression of ABO antigens on ductal ephithelium may explain this unique type of immune mediated injury.

Recurrent Hepatitis C

Hepatitis C universally recurs after liver transplantation. Although recurrent disease usually progresses slowly, about 5-10% of patients develop end-stage liver disease within two years after transplant. These patients develop a unique form of severe cholestatic hepatitis. Sometimes, the histological features of chronic rejection and recurrent hepatitis C are difficult to distinguish. In such cases, measurement of HCV RNA levels, which are persistently high in patients with cholestatic hepatitis, may help to differentiate between the two pathologies (15).
In patients with cholestatic hepatitis, liver biopsies initially show variable degrees of portal inflammation that is predominantly lymphocytic, in association with piecemeal necrosis and only minimal bile duct injury (16). Later, biopsies may show signs of progressive cholestasis with the appearance of ballooning degeneration, bile duct proliferation and canalicular cholestasis. Over time, various degrees of fibrosis develop that may progress to cirrhosis. In general, cholestatic hepatitis ranges in severity and is not always associated with rapid graft failure, although significant histological abnormalities are frequent (16).
One possible explanation for rapidly progressive recurrent hepatitis C after transplant is the enhanced diversity of HCV quasispecies, resulting in the emergence of many new pathogenic variants under the effect of immunosuppression (17).

Vascular problems

Diminished arterial flow to the hepatic graft may lead to development of ischemic bile duct damage and hepatic infarcts. Hepatic artery thrombosis or stenosis is a major cause of extrahepatic cholestasis due to the development of bile duct strictures (18). A rather rare complication is an outflow obstruction due to narrowing at the hepatic vein anastomosis or because of posttransplant Budd-Chiari syndrome, which causes perivenular hepatocyte cell damage associated with cholestasis.

Extrahepatic cholestasis

Biliary strictures are responsible for the majority of cases of posttransplant extrahepatic cholestasis (Table 1). There are two major forms of bile duct strictures: anastomotic and ischemic-type. Anastomotic bile duct strictures are usually associated with a technical problem that can be resolved by non-invasive radiological techniques or by surgical repair. On the other hand, ischemic-type biliary strictures may be associated with profound changes of the entire intrahepatic and extrahepatic bile duct system, requiring retransplantation. Ischemic-type biliary strictures are formed due to diminished arterial blood supply in patients with hepatic arterial thrombosis or stenosis or as a late consequence of ischemic-reperfusion bile duct damage (19). Although recurrent cholangitis and sepsis may indicate a need for urgent retransplantation, some patients may maintain their graft for many years and present with clinical features of chronic cholate cholestasis, including pruritus and fat malabsorption. These patients run a slowly progressive disease course, which results in the development of a secondary biliary cirrhosis.
Recurrent primary sclerosing cholangitis (PSC) after transplant was considered to be rare, but reports of recurrent disease are increasing (20). A combination of chronic rejection and disease recurrence may sometimes make it difficult to define the etiology of the cholangiopathy. Cholestasis due to impaired excretory bile flow is a feature of both processes. A milder degree of cholestasis may be also found in the immune-mediated injury of biliary epithelium, in rare cases of recurrent primary biliary cirrhosis (21).
Other rare forms of extrahepatic bile duct obstruction that may be associated with severe cholestasis have been reported. Mucocele develops from the remnant stump of the donor cystic duct and may obstruct the main bile duct (22). Similarly, extrahepatic tumor (e.g., cholangiocarcinoma) in patients transplanted for PSC (23) or post-transplant pancreatitis may also obstruct the extrahepatic bile flow. In general, it is important to define the site of obstruction using percutaneous transluminal cholangiograpy (PTC) or endoscopic retrograde cholangiopancreatography (ERCP) in order to design appropriate therapeutic measures.

In summary, cholestasis is commonly found in liver biopsies after transplant and reflects intrahepatic or extrahepatic impairment of bile flow. Other histological features on liver biopsy, as well as the patient's medical history and biochemical parameters, may help define the etiology of the cholestasis. In patients with intrahepatic cholestasis due to impaired hepatocyte secretory function (e.g., ischemia-reperfusion or sepsis), recovery depends upon removal of the underlying cause and the potential of the cells to regenerate. Bile acid deposition within hepatocytes and bile ductules may perpetuate cellular damage. Because functional impairment of bile excretion is due to cellular injury, bile salt treatment with tauroursodeoxycholic acid is of small benefit in these cases.
While anastomotic strictures and single non-anastomotic biliary strictures can be managed by invasive radiology and surgical techniques, multiple non-anastomotic intrahepatic biliary strictures indicate a need for retransplantation.

References

  1. Koopen NR, Müller M, Vonk RJ, et al. Molecular mechanisms of cholestasis: causes and consequence s of impaired bile formation. Biochim Biophys Acta 1998; 1408: 1-17.
  2. Curtin JC, Cantino D, Biasi F, et al. Reperfusion damage to the bile canaliculi in transplanted human liver. Hepatology 1996; 24: 1053-57.
  3. Colina F, Lopez-Carreira M, Moreno E, et al. A clinopathologic review of 8 liver graft primary non-function. Hepatogastroenterology 1995; 42: 212-21.
  4. Desmet VJ. Histopathology of cholestasis. Verh Dtsch Ges Pathol 1995; 79: 233-40.
  5. Gonzales-Flecha B, Curtin JC, Boveris A. Time course and mechanism of oxidative stress and tissue damage in rat liver subjected to in vivo ischemia-reperfusion. J Clin Invest 1993; 91: 456-64.
  6. Yersiz H, Shaked A, Olthoff K,et al. Correlation between donor age and the pattern of liver graft recovery after transplantation. Transplantation 1995 27;60: 790-94.
  7. Kiuchi T, Kasahara M, Uryuhara K, et al. Impact of graft size mismatching on graft prognosis in liver transplantation from living donors. Transplantation 1999 27;67:321-27.
  8. Sanchez-Campos S, Lopez-Acebo R, Gonzalez P, et al. Cholestasis and alternations of glutathione metabolism induced by tacrolimus (FK506) in the rat. Transplantation 1998; 66: 84-88.
  9. Nakache R, Rudick V, Fiodorov D, et al. Cumulative damaging effect of liver hypoperfusion and cyclosporine a on the peribiliary capillary plexus: a study in an isolated dually perfused rat model. Transplantation 1999; 68: 1651-60.
  10. Fisher A, Mor E, Hytirogulou P, et al. FK506 hepatotoxicity in liver allograft recipients. Transplantation 1995; 59: 1631-32.
  11. Bolder Urlich, Ton-Nu HT, Schteingart CD, et al. Hepatocyte transport of bile acids and organic anions in endotoxemic rats: impaired uptake and secretion. Gastroenterology 1997; 112: 214-25.
  12. Jansen P, Müller M. Early eventsin sepsis-associated cholestasis. Gastroenterology 1999; 116: 486-88.
  13. Wiesner RH, Ludwig J, van Hoek B, Krom RA. Current concepts in cell-mediated hepatic allograft rejection leading to ductopenia and liver failure. Hepatology 1991; 14: 721-29.
  14. Worster AS, Ghent CN. Cholangiographic appearance of ductular rejection of ABO-incompatible liver transplants. J Clin Gastroenterol 1992; 15: 222-24.
  15. Doughty AL, Spencer JD, Cossart YE, et al. Cholestatic hepatitis after liver transplantation is associated with persistently high serum hepatitis C virus RNA levels. Liver Transpl Surg 1998; 4: 15-21.
  16. Cotler SJ, Taylor SL, Gretch DR, et al. Hyperbilirubinemia and cholestatic liver injury in hepatitis C-infected liver transplant recipients. Am J Gastroenterol 2000; 95: 753-59.
  17. Pessoa MG, Bzowej N, Berenguer M, et al. Evolution of hepatitis C virus quasispecies in patients with severe cholestatic hepatitis after liver transplantation. Hepatology 1999; 30: 1513-20.
  18. Abbasoglu O, Levy MF, Vodapally MS, et al. Hepatic artery stenosis after liver transplantation; incidence, presentation, treatment and long term outcome. Transplantation 1997; 63: 250-5.
  19. Sebagh M, Farges O, Kalil A, et al. Sclerosing cholangitis following human orthotopic liver transplantation. Am J Surg Pathol 1995; 19: 81-90.
  20. Graziadei IW, Wiesner RH, Marotta PJ, et al. Long-term results of patients undergoing liver transplantation for primary sclerosing cholangitis. Hepatology 1999 Nov;30(5):1121-7.
  21. Van de Water J, Gerson LB, Ferrel LD, et al. Immunohistochemical evidence of disease recurrence after liver transplantation for primary biliary cirrhosis. Hepatology 1996; 24: 1079-84.
  22. Zajko AB, Bennett MJ, Campbell WL, Koneru B. Mucocele of the cystic duct remnant in eight liver transplant recipients: findings at cholangiography, CT, and US. Radiology 1990 177):691-3.
  23. Goss JA, Shackleton CR, Farmer DG, et al. Orthotopic liver transplantation for primary sclerosing cholangitis. A 12-year single center experience. Ann Surg. 1997;225:472-81.

Address for correspondence:

Eytan Mor, M.D.
Rabin Medical Center, Beilinson Campus
Petah Tikva, 49100
Israel

Phone: 972 3 9376565
Fax: 972 3 937 6473
E-mail: eytanmor@netvision.net.il


Experimentálne ovplyvnenie prezervačného poškodenia pri autotransplantácii obličky

Baláž, P., Jackanin, S., Jakubík, P., Matia, I., 1 Pomfy, M., 2 Franko, J., 3 Kitka, M.
1 Ústav lekárskej histológie a embryológie LF, UPJŠ, Košice
prednosta: Doc. MVDr. M. Pomfy, CSc.
2 I.Chirurgická klinika, FNsP, Košice
prednosta: Prof. MUDr. J. Bober, CSc.
3 Klinika úrazovej chirurgie FN L.Pasteura, Košice
prednosta: Doc. MUDr. M. Kitka, CSc.

(Víťazná práca fakultného kola ŠVOČ - Košice ).

Súhrn

Autori si stanovili tieto ciele : (1) zaviesť a otestovať model poškodenia obličkového štepu pri autotransplantácii a (2) vyhodnotiť vplyv pridania Mercurochromu a L - arginínu na prezervačné poškodenie autotransplantovanej obličky. Použili 51 psov rozdeleních do 3 skupín : a) ( n = 15 ) bola odobratá oblička prepláchnutá roztokom PBS 140, b) ( n = 16 ) bola oblička preplachnutá roztokom PBS 140 + 5 mg Mercurochromu, c) ( n = 20 ) sa transplantát prezervoval roztokom PBS 140 + 87.1 mg / 1mmol/l/ L - arginínu. Po 10 - 15 hodinovej studenej ischémii boli obličky autotransplantované na vasa iliaca opačnej strany a druha oblička bola odstranená. Po spracovananí výsledov neparametrickou analýzou rozptylu testom podľa Kruskal - Wallisa ( p < 0,05 ) boli zaznamenané štatisticky významné rozdiely u hodnôt kreatinínu a urey. Zistili, že pridanie L - arginínu do konzervačného roztoku ( PBS 140 ), znižuje prezervačné poškodenie autotransplantovanej obličky.
Kľúčové slová : oblička - autotransplantácia - prezervačné poškodenie - L - arginin

Summary

The experimental influence on the presevation injury in autotransplanted kidneys
Baláž, P., Jackanin, S., Jakubík, P., Matia, I., 1 Pomfy, M., 2 Franko, J., 3 Kitka, M.
We aimed to (1) introduce and test the model of renal graft injury in autotransplantation and to (2) evaluate the influence of Mercurochrome and L -arginine on presevation injury of autotransplanted kidney.We used 51 mongrel dogs divided to 3 groups, one kidney was harvested and preservation solution was: a) ( n = 15 ) PBS 140 solution, b) ( n = 16 ) PBS 140 solution with addition of 5mg of Mercurochrome to 0,5 l of solution, c) ( n = 20 ) PBS 140 solution + 87.1mg ( 1mmol/l ) of L - arginin. After 10 - 15 hours of cold ischaemia, the kidneys were autotransplanted to vasa iliaca of the contralateral side and the second kidney was removed. Statistically significant differencies
( Kruskal - Wallis, p < 0,05 ), were observed in serum urea and kreatinine levels.
Conclusion: the addition of L - arginine to conservation solution decreases the preservation injury of autotransplanted kidneys as was demonstrated by faster onset of renal graft function and faster values stabilisation of selected biochemical parameters ( kreatinine, urea ).
Key words : kidney - autotransplantation - preservation injury - L - arginin

Úvod

Rok 1902 je pokladaný za medzník zrodu prenosu orgánov, kedy ako prvý transplantoval obličku u psa viedenský chirurg Emerich Ulmann zo sutúrou renálnych ciev na arteria carotis a vena jugularis pomocou Payerovho prstenca.
Transplantácia obličiek ako neoddeliteľná súčasť dialyzačno - transplantačného programu je liečebnou metódou chorých s ireverzibilným zlyhaním funkcie obličiek. Samotnej transplantácii obličiek predchádza ich odber, ktorý je jedným z najzávažnejších etáp celého výkonu. Taktika a technika odberu je už niekoľko rokov detailne prepracovaná. Avšak aj pri dodržaní všetkých zásad pre úspešnú transplantáciu sa u 10 - 60 % transplantovaných obličiek vyvinie dočasná dysfunkcia štepu. Snahou skrátiť trvanie tejto dočasnej dysfunkcie je pridanie rôznych vazoaktívnych, energiu šetriacich a antioxidačných látok do konzervačného roztoku. V našej práci sme sa sútredili na možnosti zníženia prezervačného poškodenia obličky. Ako aditíva do prezervačného roztoku ( PBS 140 ) sme použili L - arginín, ktorého protektívny účinok je založený na jeho schopnosti zabrániť mikrovaskulárnej konstrikcii a na znížení poruchy permeability stimuláciou endogénnej tvorby NO a Mercurochrome, ktorý pomáha návratu energetického metabolizmu do normálnych hodnôt, priaznivo ovplyvňuje metabolizmus iónov ( Na, K ) a normalizuje hodnoty niektorých enzýmov ( Laktát dehydrogenáza, Malonát dehydrogenáza ).

Cieľ štúdie

1. Zaviesť a otestovať model poškodenia obličkového štepu pri autotransplantácii
2. Vyhodnotiť vplyv Mercurochromu a L - arginínu na prezervačne poškodenie autotransplantovanej obličky

Materiál a metódy

Použili sme 51 psov - krížencov oboch pohlaví, ktorí boli rozdelení do 3 skupín. V prvej skupine ( n = 15 ) bola psom odobratá jedna oblička, ktorá bola prepláchnutá 100 ml roztoku PBS 140 ( z výšky 100 cm, 4 min.). V druhej ( n = 16 ) a tretej ( n = 20 ) skupine sa oblička preplachovala za rovnakých podmienok roztokom PBS 140 s pridaním 5 mg Mercurochromu, resp. 87.1 mg L - arginínu. Následne boli obličky uložené do konzervačného roztoku o teplote 4°C s rovnakým zložením. Po 10 - 15 hodinovej studenej ischémii boli všetky obličky autotransplantované do bedrovej jamy ( pravá obličky do ľavej bedrovej jamy a opačne ). Výkon bol vykonaný pod ATB clonou ( Claforan, resp. Cefotaxime ) za aseptických podmienok.
Po vypreparovaní iliackých ciev boli naložené cievne svorky, cievy boli nastrihnuté a prepláchnuté roztokom Heparínu. Cievy obličky boli podľa potreby nastrihnuté. Najprv bola našitá vena renalis end - to - side na vena iliaca communis pokračujúcim stehom ( Prolen 5/0 ), potom arteria renalis end - to -side na arteria iliaca communis. Po celý manipulačný čas bola oblička chránená ľadovou drťou v sterilnej rúške. Po došití anastomóz sme intravenózne podali Heparín 25j/kg a boli uvoľnené cievne svorky. Následne sme po opatrení distálneho konca ureteru stentom vykonali ureteroneocystostómiu v dvoch vrstvách ( Ethibond 3/0 ). Nakoniec bola odstránená kontralaterálna oblička. Brušná stena bola zošitá v anatomických vrstvách.
Poperačne boli psy podľa príjmu tekutín hydratovaní roztokom 5 % glukózy a päť dní bol subkutánne podávaný Fraxiparine 300 AXa j./kg. Biochemické parametre - sérový kreatinín, urea, Na, K, leukocyty a FW boli merané predoperačne a každý nepárny pooperačný deň, teplota a klinický grading boli merané denne. Z doplňujúcich vyšetrení sme vykonávali u jedného psa z každej skupiny izotopovú renografiu na 3, 9, 16 a 29 deň, vylučovaciu urografiu a dynamickú gamagrafiu štepu po stabilizácii biochemických hodnôt. Z troch obličiek prepláchnutých za štandardných podmienok roztokom PBS 140, roztokom PBS 140 s Mercurochromom a PBS 140 s L - arginínom boli po 10 - 15 hodinovej konzervácii pri 4°C urobené excízie, ktoré boli uložené do 10 % formalínu a vyšetrené svetelnou mikroskopiou.
Hodnoty biochemických parametrov boli štatisticky spracované neparametrickou analýzou rozptylu testom podľa Kruskal - Wallisa. Štatisticky významné rozdiely boli stanovované na hladine p < 0,05.

Výsledky

Vyhodnotených bolo 7 psov zo skupiny PBS 140, 4 zo skupiny Mercurochrome a 7 z L - arginínovej skupiny. Priemerné maximálne hodnoty kreatinínu a urey boli najnižšie v skupine L - arginínu ( 385.6µmol/l, 29.2mmol/l ) a to na tretí, resp. štvrtý POD, zatiaľčo v skupine PBS 140 boli maximálne hodnoty ( 793.7µmol/l a 54.8mmol/l ) na štvrtý, resp. piaty POD. Obličkové funkcie boli stabilizované na siedmy POD v skupine L - arginín a na 15-ty deň v sk. PBS 140, pričom hodnoty sa u oboch skupín vrátili do fyziologického rozmedzia. U skupiny Mercurochrom boli maximálne hodnoty namerané na štvrtý deň ( 558.6µmol/l, 46.1mmol/l ), potom však po niekoľkých dňoch poklesu hladín urey a kreatinínu došlo ku komplikáciám v OP rane, ktoré si vyžiadali chirurgickú revíziu v celkovej anestézii, po ktorej došlo k vzostupu hladín urey a kreatinínu až do úmrtia kvôli následnému zlyhaniu štepu. Štatistický význam u sérového kreatinínu bol nameraný na tretí deň, keď sa líšili hodnoty skupiny L -arginínu voči skupinám PBS 140 a Mercurochromu. Na 11 - ty a 13 - ty deň sa signifikantne líšili hodnoty skupiny Mercurochromu voči skupine PBS 140 a L -arginínu. U sérovej hladiny urey bola situácia obdobná, len významnosť bola zistená na tretí aj piaty deň v prospech skupiny L - arginínu a na 13 - ty deň v neprospech Mercurochromu.
Z celkového počtu 51 psov bolo zaznamenaných 15 včasných chirurgických komplikáci. Hlavnými príčinami zlyhania obličkového štepu boli : trombóza a. et v. renalis, stenóza anastomózy, krvácanie z operačnej rany a v jednom prípade dehiscencia ureteroneocystostómie. V 3 - 5 pooperačnom dni sa u 10 zvierat vyskytol invaginačný ileus s fatalnymi následkami.
Zobrazovacími metódami sme u skupín PBS 140 a L - arginín dokázali funkčnosť autotransplantovanej obličky. Na rádioizotopovú renografiu bol použitý i.v. podaný Hippuran značený iódom. Pri vylučovacej urografii bol ako kontrastná látka i.v. podaný Telebrix 380 a ako rádiofarmakum na dynamické gamagrafické vyšetrenie i.v. podané DTPA značené iódom ( Obr. 1, 2, 3 ).

Obr.1 - Izotopový renogram zhotovený na 29. deň po autoTx obličky u reprezentativneho psa so skupiny PBS 140. Ide o parenchýmový typ krivky s naznačenou exkréčnou fázou.

Obr.2 Zobrazenie autotransplantovanej obličky pomocou i.v. vylučovacej urografie (3. minúta)

Po preplachu a 12 hodinách konzervácie sme vykonali excíziu obličiek u jednotlivých skupín a mikroskopicky sledovali ich prezervačné poškodenie. Boli zistené len fokálne známky poškodenia vo forme vakuolizácie malej časti kôrových kanálikov, a to najviac v oblasti distálnych stočených tubulov. Okrem HE farbenia, pre povahu hydropickej dystrofie svedčí aj vzhľad vakuol pri farbení metódou PAS. Prítomné boli aj fokálne známky edému interstícia. Celkove sa nezistili podstatné kvalitatívne a kvantitatívne rozdiely medzi jednotlivými skupinami ( Obr. 3, 4, 5 ).

Obr.3 Intersticiálny edém - HE

Obr.4 Hydropická dystrofia - HE

Obr.5 Hydropická dystrofia - PAS

Diskusia

Vplyv L - arginínu stimuláciou endogénnej produkcie NO (1) umožňuje predísť kapilárnej konstrikcii v reperfundovanej obličke. Ďalší priaznivý vplyv
L -arginínu je jeho schopnosť redukcie intersticiálneho edému tkaniva, kvôli dokázanému vplyvu NO na mikrovaskulárnu permeabilitu sprostredkovanú endotel - dependentnými mechanizmami (2). NO znižuje permeabilitu relaxovaním endoteliálnych buniek, čím dochádza k zúženiu šírky endoteliálnych spojení (3). Nami zistený pozitívny vplyv L - arginínu na prezervačne poškodenie je v súlade s výsledkami predchádzajúcich prác ( 4, 5 ).
Bol dokázaný priaznivý efekt ortuťnatých derivátov fluoresceínu (Mercurochrome) na metabolizmus ischemického tkaniva. Mercurochrome pomáha návratu energetického metabolizmu do normálu, hlavne ovplyvnením metabolizmu iónov ( Na, K ), potláčaním hromadenia laktátu v ischemickom tkanive, udržiavaním koncentrácie ATP a normalizovaním hladín niektorých enzýmov ( LDH, MDH ) ( 6, 7, 8 ). Taktiež stabilizuje integritu a kohéziu vaskulárneho endotelu ( 9 ).
Na základe dynamiky biochemických parametrov ( urea, kreatinín ) až do výskytu pooperačných komplikácií by sme mohli predpokladať, že Mercurochrome priaznivo ovplyvňuje prezervačne poškodenie obličky, ktoré bolo v súlade s výsledkami predchádzajúcich štúdií ( 6, 9 ). Keďže v našom experimente nedošlo u tejto skupiny k definitívnej stabilizácii biochemických parametrov, nemôžme sa o predpokladanom pozitívnom vplyve Mercurochromu zodpovedne v našich záveroch vyjadriť.

Zaver

Podľa nami získaných výsledkov L-arginín ako aditívum do konzervačného roztoku (PBS 140), znižuje prezervačne poškodenie autotransplantovanej obličky, čo vyplýva z rýchlejšieho nástupu funkcie obličkového štepu a stabilizácie hodnôt vybraných biochemických parametrov (kreatinín, urea).
Vzhľadom na skutočnosť, že v skupine s použitím Mercurochromu nedošlo ani u jedného experimentálneho zvieraťa k trvalému návratu funkcie štepu kvôli jeho predpokladanému poškodeniu vynútenou sekundárnou celkovou anestéziou, nemôžme sa vyjadriť o pozitívnom vplyve Mercurochromu na zníženie prezervačneho poškodenia autotransplantovanej obličky. Objasnenie možnej spojitosti Mercurochromu s pooperačnými komplikáciami v operačnej rane si vyžaduje ďalšie skúmanie.

Literatúra

  1. Huk, I., Nanobashvili, J., Neumayer, Ch. et al.: L - arginine treatment alters the kinetics of nitric oxide and superoxide release and reduces ischemia/reperfusion injury in skeletal muscle. Circulation, 96, 1997: 667 - 675
  2. Kubes, P., Granger, D. N.: Nitric oxide modulates microvascular permeability. Amer. J. Physiol., 262, 1992: H611 - H615
  3. Oliver, J. A.: Endotelium - derived relaxing factor contributes to the regulation of endothelial permeability. J. Cell Physiol., 151, 1992: 506 - 511
  4. Huk, I., Nanobashvili, J., Orljanski, W. et al.: L - arginine treatment in ischemia/reperfusion injury. Čas. Lék. Čes., 137, 1998: 496 - 499
  5. Wszola, M., Fesolowicz, S., Krzesniak, N. et al.: UW Gluconate with L -arginine allows save preservation of ischemically damaged kidneys. 10th European Student Conference ( Humboldt University of Berlin, October 20th - 23th, 1999 ), Abstract book, 309
  6. Málek, P., Kolc, J., Vrána, M. et al.: Komplexní účinek Mercurascanu na ischémií poškozený myokard. Čas. Lék. Čes., 114, 1975: 753 - 757
  7. Málek, P., Vávrejn, B., Kolc, J. et al.: Studies on the therapeutic use of Mercurascan. Part I.: Distribution of Mercurascan in the body in experimental and clinical myocardial ischaemia. Int. J. clin. Pharmacol., 10, 1974: 266 - 272
  8. Kučerová, V., Kolc, J., Málek, P.: Studies on the therapeutic use of Mercurascan. Part III.: Influence of Mercurascan on some metabolic changes in experimental myocardial ischaemia in dogs. Section I.: Energetic and ionic metabolism. Int. J. clin. Pharmacol., 11, 1975: 40 - 51
  9. Málek, P., Kolc, J., Rossmann, P. et al.: The effect of mercury derivatives of fluorescein on allotransplant kidney in experiment. Czechoslovac Medicine, 1, 1978: 99 - 103
  10. Málek, P., Píša, Z.: Transplantace orgánú ( historie, současnost a perspektivy ). Čas. Lék. Čes., 115, 1976: 969 - 978
  11. Kočandrle, V., Hejnal, J., Hahn, M. et al.: Taktika a technika transplantací ledvin. Prakt. Lékař (Praha), 57, 1977: 407 - 409
  12. Kučera, M., Adamec, M.: Chirurgické komplikace po transplantaci ledviny. Rozhl. Chir., 75, 1996: 445 - 449
  13. Bassiri, A., Amiransarii, B., Yazdani, M. et al.: Renal transplantation using ureteral stents. Transplantation Proceedings, 27, 1995: 2593 - 2594.

Adresa pro korespondenci:

Stanislav Jackanin
Rosná 6
040 01 Košice
Slovensko
e-mail: jackanin@post.cz

Abstrakta

Monstrosní polyp žaludku jako příčina krvácení do GIT

Peritonitis, způsobená endoskopicky zavedeným stentem

Drábek, J., Keil, R., Suldovská, H., Šmejkal, P.

Interní klinika 2. LF UK Praha, FN Motol
III. chirurgická klinika l. LF UK Praha, FN Motol

Souhrn

Cílem sdělení je referovat o dvou neobvyklých diagnózách, které se vyskytly u jedné pacientky v časovém horizontu 7 měsíců.
V dubnu 1999 byla 65letá nemocná hospitalizována na našem pracovišti pro krvácení do horních partií GIT. Jako zdroj byl identifikován 8 cm velký stopkatý polyp antra žaludku, který prolaboval do duodena. Polyp se zdařilo endoskopicky odstranit. Histologicky se jednalo o zánětlivý fibroidní polyp.
O 6 měsíců později byla nemocná hospitalizována na našem pracovišti pro obstrukční ikterus. Byla nalezena choledocholitiáza, která byla endoskopicky vyřešena. K cholecystektomii nebylo přistoupeno pro příliš velké operační riziko, vzhledem k ostatním interním diagnosám. Nemocná byla zajištěna plastovým drénem a byla propuštěna. O měsíc později byla přijata na III. chirurgickou kliniku pro příznaky apendicitidy. Byla z vitální indikace revidována a peroperačně byl nalezen intaktní apendix, difusní peritonitida a plastový stent, který ležel volně mezi kličkami ilea. Perforační otvor se nalézt nepodařilo. Byla provedena drenáž a laváž, pacientka se záhy zotavila a byla propuštěna.
Ačkoli 2 výše uvedené diagnosy z oblasti gastroenterologie spolu nesouvisí, je pozoruhodné, že se vyskytly u jedné pacientky v krátkém časovém odstupu.