- Email: [email protected]
The endoscopic measurement of intravascular pressure and flow in oesophageal varices
126
Journal of Hepatology, 1988; 7:126-131 Elsevier
HEP 00433
Leader
The endoscopic measurement of intravascular pressure and flow in oesophageal varices
M. S t a r i t z a n d K . - H . M e y e r z u m B i i s c h e n f e l d e I. Medizinische Klinik und Poliklinik, Johannes-Gutenberg Universitiit, Mainz (F. R. G. )
Introduction
Endoscopic
pressure
measurement
-
different
methods
Several new techniques to investigate the portal hypertensive patient have been described in recent years. Pressure and flow measurements in oesophageal varices obtained endoscopically have gathered Widespread attention as reflected by numerous current papers. Intraoesophageal pneumatic pressure sensoring by using a pneumatic pressure capsule, direct intravariceal fine needle puncture with or without perfusion of the needle, as well as endoscopic Doppler ultrasonography have been introduced to further elucidate the pathophysiology of portal hypertension, and the effect of several physiological parameters and drugs on oesophageal variceal pressure has been studied. New methods are important only if they provide insight into the pathophysiology of portal hypertension, or if they lead to new therapeutic approaches. The following article emphasizes the different techniques of flow and pressure measurement in oesophageal varices, presents the results obtained, and discusses their presumed clinical value.
Endoscopically guided variceal puncture Puncture of oesophageal varices was first performed by Palmer during rigid oesophagoscopy under general anaesthesia [1,2]. This procedure did not gain acceptance, since general anaesthesia and rigid endoscopy were too invasive to use for studies. Additionally, effects of general anaesthesia on portal hypertension could not be ruled out. Recently, however, variceal fine needle puncture has been reported as a simple approach for the measurement of intravariceal pressure [15]. After intravenous premedication with diazepam the patients underwent flexible oesophagoscopy by a standard technique. During continuous endoscopic observation variceal columns were punctured 5-10 cm above the cardia with a fine needle having an outer diameter of 0.71 mm. The very thin capillary lumen of this needle requires perfusion by a capillary hydraulic perfusion pump [3]. A pressure transducer attached to the perfusion system allows the pressure at the tip of the
Correspondence: M. Staritz, M.D., P.D., I. Medizinische Klinik und Poliklinik, Johannes-Gutenberg-Universit~it, Langenbeckstr. 1, D-6500 Mainz, F.R.G.
0168-8278/88/$03.50 © 1988 Elsevier Science Publishers B.V. (Biomedical Division)
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
PERFUSION
PUMP
WRI TER
-
-
ENDOSCOPE
-
-
VARIX
-
-
OESOPHAGUS
-
-
FINE NEEDLE
127
(Fig. 2) is fixed on the tip of the endoscope. An elastic membrane, which is part of the device, touches and slightly compresses the varix wall. Continuous insufflation of air into the capsule (Fig. 2) serves for maintaining the pressure in the capsule. When applied to a varix the pressure acting on the flexible membrane of the gauge stops air circulation. The pressure in the circuit then increases until it equals the pressure applied onto the membrane. Theoretically the pressure required for maintenance of air circulation equals that in the varix. According to this assumption pneumatic pressure sensoring can be used for indirect assessment of the pressure in varices [8,9]. A similar device in which air insufflation is provided by a constant flow has been introduced recently [10]. Neither, however, is yet available commercially.
Comparison of the methods
Fig. 1. Scheme of endoscopically guided variceal fine needle puncture. needle to be obtained (Fig. 1). Intravascular oesophageal variceal pressure (IOVP) is defined as the gradient between intravariceal and intraoesophageal pressure, the latter serving as zero-reference. A similar puncture method but without perfusion of the needle has been used by other investigators [5-7]. This technique comprises some disadvantages; e.g., the sensitivity for pressure alterations is lower and it is difficult to recognize a paravasal needle position. Additionally, in most patients the larger needle diameter requires variceal sclerosing therapy after the pressure measurements. Since most authors do not perform prophylactic sclerosing therapy they could not investigate patients without previous variceal haemorrhage.
Pneumatic pressure sensor
The pneumatic pressure sensor method also requires flexible oesophagoscopy. The pressure device
The variceal puncture technique is easy to perform and the pressure values are reproducible [4]. However, the procedure is in.vasive. Pressure monitoring using a pneumatic pressure sensor is less invasive. A comparison of both methods demonstrated that the pneumatic pressure sensor is suitable-only for patients with large varices (grade 11I and IV). With smaller varices (grade I and II) this technique is difficult to perform and the pressures obtained are not
4
tII: f
/'Varicosity Fig. 2. Scheme of the pneumatic pressure sensor. Its working principle: part of the pressure device is a flexible membrane which is positioned onto the varicosity. The capsule is perfused with air (e = flow into the capsule, i and h = recirculation). After compression of the flexible membrane by the variceal wall, pressure in the capsule, maintained by a compressor (d), rises until it equals that in the varix. This pressure is depicted on a manometer (c).
128
M. STARITZ AND K.-H. MEYER ZUM BOSCHENFELDE
representative due to artefacts caused by movement of the patients, peristalsis of the oesophagus and deviation of the pressure capsule from the variceal wall [10,11].
Assessment of flow in oesophageal varices Very few papers dealing with the measurement of flow in oesophageal varices are available. McCormack and co-workers [12,13] used a Doppler probe which is so small that it can be advanced through the channel of a normal flexible endoscope, working similarly to the transabdominal probe [14]. This method is based on the principle that ultrasonic waves with defined wavelengths are reflected by blood cells. This causes modulation of the wavelength depending on the velocity of passing erythrocytes (Doppler effect). The difference between the wavelength transmitted and received allows an estimation of direction and velocity of blood flow in varices.
Results obtained by the different techniques • Portal hypertension physiology
Several data concerning the pathophysiology of
Vances grade II 32-
I
Vor,ces grade Ill
I
!
2L]Z
E 16E
8-
157z06 227±2L IOVP Basal
& IOVP
31 0_'15 373zlL IOVP Valsolva
Fig. 3. Correlation between intravascular oesophageal variceal pressure and size of oesophageal varices under basal conditions and during Valsalva's manoeuvre. No difference in relative pressure elevation (A IOVP) was observed (grade 11 13.6 + {).8vs. grade III 13.5 + 1.5 mmHg).
portal hypertension and pharmacological effects on portal pressure have been obtained in recent years. It has been demonstrated [4,15] that in different varices of an individual patient the pressure is nearly identical. Therefore, repeated measurement in different varices to obtain the IOVP of an individual patient is not necessary. In different patients, however, the pressure in small varices is generally lower than in large varices (Fig. 3). This was the common finding of several authors [4,6,7,9,10]. Of particular interest was the question of the role of variceal pressure in the development of variceal haemorrhage. One of our follow-up investigations of patients who had previously undergone a shunt operation showed that individual patients with sufficient shunt could be easily identified by a decrease of variceal size from grade lIl to grade 1, accompanied by a significant decrease of variceal pressure [15]. In contrast, patients who rebled after a shunt operation had newly developed varices, the pressure and size of which were found to be similar to those values obtained before the shunt operation. Another study included 29 patients with histologically proven cirrhosis (Child A). Sixteen had recently bled from their varices, 13 had not. In all subjects variceal size had been classified endoscopically. Grade 1, II and IIl varices were found in 0, 6 and 10 patients, respectively, with recent haemorrhage, but only in 2, 9 and 2 patients, respectively, without previous bleeding. Variceal pressure of the bleeders amounted to 27 _+ 3.5 mmHg and to 16.5 _+ 1.8 mmHg in the non-bleeder group (Fig. 4) [16,17]. These findings were confirmed by Gross and Erhard [7]. The same authors tried to classify patients with recent haemorrhage according to their IOVP. In subjects with early relapsing haemorrhage, variceal pressure was significantly higher (37.5 mmHg) than in patients with late relapse (27.5 mmHg) or in those without further rebleeding (24.5 mmHg). These results support the opinion that variceal pressure could be a potential risk factor for the development of variceal haemorrhage. It raises the question as to which physiological parameters potentially influence variceal pressure. It has been demonstrated that intraabdomina[
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
phalad direction. Flow increased during inspiration and decreased during expiration. In some patients, however, flow occurred in both directions. The authors also performed recordings under general anaesthesia with positive pressure ventilation. Under these conditions, the direction of total flow became caudal in certain varices, decreasing during inspiration. This observation suggests the presence of perforating or communicating veins. Postmortem dissection confirmed the presence of large perforating veins in one of the patients investigated. Since flow monitoring identified perforating veins, the authors concluded that an ultrasonic Doppler probe should be a reliable aid for successful endoscopic sclerotherapy when injecting the sclerosants into the perforating veins.
mmH9 i 40-
35
•
129
O
25
Pharmacological studies
0
I
'
II
'ui'nvll a
•
I
'
II
~ I I I ~ I V I[
I
~
II
b
~ III ' IV I
o
c
Fig. 4. Con]parison of the variceal prcssur¢ in palients with rcccnl variccal hacmorrhagc who dcvclopcd early (c), late (b) or
no further reblceding (a). pressure elevation causes significant elevation of the pressure in the varices. One of our investigations [4] demonstrated that Valsalva's manoeuvre increased the variceal pressure by approximately 15 mmHg (Fig. 3). Similar findings were reported by Hosking et al. [18], whilst Schneider and Lackner [6] observed a pressure elevation up to 75 mmHg. Similar values were obtained during deep inspiration and expiration [6]. Another study was performed to elucidate the effect of body position on variceal pressure [19]. Pressures were measured in the horizontal position and during deviation by 30 ° either with feet down or head down. Since no significant pressure changes were obtained, the results suggest that body position does not affect variceal pressure. Very little information is available concerning the flow in varices. McCormack et al. [12,13] observed in 18 patients that blood in the varices flowed in a ce-
Several data suggest that variceal pressure is one of the main risk factors for the development of variceal bleeding. Most of.the pharmacological studies, therefore, had the aim of elucidating the effect of drugs that presumably lower variceal pressure. Nitroglycerin has been studied by two groups; according to their results the effect of the drug seems to depend on the molecular structure of the nitroglycerin type used. Glyceryl trinitrate ( 1.2 rag), having a short half life (5-11) rain) due to first-pass inactivation in the liver, causes a significant decrease of variceal pressure when applied sublingually [4]. In contrast, isosorbide dinitrate applied endoscopically into the duodenum had no effect on variceal pressure, although systemic pressure was decreased [20]. Somatostatin was investigated by three groups. Jenkins et al. [21] found a significant decrease of variceal pressure by approximately 509'o of the basal value after administration of somatostatin. Our group and Kleber et al. [22] were not able to confirm this effect. The different schedules of administration, particularly the simultaneous commencement of bolus injection and somatostatin perfusion may, to some extent, explain these contradicting results. Glycylpressin was also tested. The effect on intra-
130
M. STARITZ AND K.-H. MEYER ZUM BUSCHENFELDE
variceal pressure was less p o t e n t than e x p e c t e d . O n l y
t e c h n i q u e s are c o n s i d e r e d to be r e f e r e n c e m e t h o d s
in a p p r o x i m a t e l y o n e third of the p a t i e n t s was the
for the r e c e n t l y d e v e l o p e d n o n - i n v a s i v e p r o c e d u r e s .
variceal p r e s s u r e l o w e r e d , by only 3 - 5 m m H g [23].
T h e latter, h o w e v e r , have p r o v e n to be a reliable al-
This u n e x p e c t e d result might explain c o n t r a d i c t i n g
t e r n a t i v e only in patients with large varices. T h e re-
results of clinical trials which did not really p r o v e the
suits r e p o r t e d so far s u p p o r t the a s s u m p t i o n that in-
beneficial effect of terlipressin in variceal h a e m o r -
travariceal pressure is one of the m a j o r risk factors
rhage [24,25].
for the d e v e l o p m e n t of variceal bleeding. F u r t h e r m o r e , there is a strong positive c o r r e l a t i o n b e t w e e n pressure and size of varices. T h e study of physiologi-
Conclusion and perspectives
cal p a r a m e t e r s and drugs influencing portal h y p e r tension is of particular interest and the effect of drugs
E n d o s c o p i c m e a s u r e m e n t s of flow and p r e s s u r e in
that p r e s u m a b l y l o w e r i n t r a v a r i c e a l p r e s s u r e can be
o e s o p h a g e a l varices are new t e c h n i q u e s p r o v i d i n g
verified
f u r t h e r insight into the p a t h o p h y s i o l o g y of portal hy-
could help to plan f u r t h e r clinical trials including
pertension.
drugs which are c o n s i d e r e d to be beneficial in pa-
Several
invasive
and
non-invasive
m e t h o d s are in use for the m e a s u r e m e n t of variceal pressure.
directly.
These
pressure
measurements
tients with portal h y p e r t e n s i o n .
U p to n o w the invasive direct p u n c t u r e
References 1 Palmer ED. On correlations between portal venous pressure and size and extent of oesophageal varices in portal cirrhosis. Ann Surg 1953: 138: 741-744. 2 Palmer ED, Brick IB. Correlation between the severity of oesophageal varices in portal cirrhosis and their propensity toward hemorrhage• Gastroenterology 1956; 30: 98-90. 3 Arndorffer RC. Steff J J, Dodds W J, et al. Improved infusion system for intraluminal oesophageal manometry. Gastroenterology 1977; 24: 7-23. 4 Staritz M, Poralla T, Meyer zum Bfischenfelde K-H. Intravascular oesophageal variceal pressure (IOVP) assessed by endoscopic fine needle puncture under basal conditions, Valsalva's manoeuvre and after glyceryltrinitrate application. Gut 1985; 26: 525-530. 5 De Reuck M, Burette A, Van Gossum M, eta[. Endoscopic measurement of the pressure in the oesophageal varices of cirrhotic patients. Correlation with portal pressure. Acta Endosc 1984; 14: 121-127. 6 Schneider B, Lackner K. Pathogenese der Osophagusvarizenblutung. Deutsche Med Wochenschr 1986; 116: 611-615. 7 Gross E, Erhard J. Endoskopisch gefiihrte Druckmessung in distalen Osophagusvarizen. Deutsche Med Wochenschr 1987; 112: 125-127. 8 Mosimann R. Nonaggressive assessment of portal hypertension using endoscopic measurement of varicea[ pressure. AmJ Surg 1982: 143: 212-214. 9 Gertsch P, Meister JJ. Pressure measurement in oesophageal varices: preliminary report on a new non-invasive method. Gut 1988; in press. 10 Bosch J, Bordas JM, Rigau J, Viola C, et al. Noninvasive measurement of the pressure of oesophageal varices using
11
12
13 14
15
16
17
18
19
an endoscopic gauge: comparison with measurements by varicea[ puncture in patients undergoing endoscopic sclerotherapy• Hepatology 1986; 6: 667-672. Staritz M, Gertsch P. Pressure measurements in oesophageal varices: first comparison of two techniques. Endoscopy 1986~ 18: 253-254. McCormack T, Smallwood RH, Walton L, et al. Doppler ultrasound probe for assessment of blood-flow in oesophageal varices. Lancet 1983: i: 677-678. McCormack T, Smith PM, Rose JD, et al. Perforating veins and blood flow in oesophageal varices. Lancet 1983; ii: 1442-1444. Ohnishi K, Saito M, Koen H, et al. Pulsed doppler flow as a criterion of portal venous velocity: comparison with cineangiographic measurements. Radiology 1985; 154: 495-498. Staritz M, Meyer zum Bfischenfelde K-H. Endoscopic measurements of intravascular pressure and flow in blood vessels of the gastrointestinal tract. Clin Gastroenterol 1986; 15: 235-247. Staritz M, Manns M. Poralla T, et al. A new method for measurement of the intravascular oesophageal variceal pressure (IOVP) and assessment of IOVP in cirrhotic patients with and without recent variceal haemorrhage [Abstract]. Gastroenterology 1985; 88: 1697. Staritz M, Poralla T, Ewe K, et al. Endoskopische Bestimmung des Osophagusvarizendruckes (Endoscopic assessment of the oesophageal variceal pressure). Schweiz Rundsch Med Prax 1984; 38:1151-1152. Hosking SW, Robinson R, Johnson AG. Effect of Valsalva's manoeuvre and hyoscinbutylbromide on the pressure gradients across the wall of oesophageal varices. Gut 1987: 28: 1151-1156. Staritz M, Rambow A, Manns M, Meyer zum Bfischenfelde
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
K-H. The effect of body position on the pressure in oesophageal varices [Abstract]. Gastroenterology 1987; 92: 1782. 20 Dawson J, West R, Gertsch P, et al. Endoscopic variceal pressure measurements: response to isosorbite dinitrate [Abstract]. Gut 1983, 24: 971. 21 Jenkins SA, Baxter JN, Corbett WA, Shields R. Effects of a somatostatin analogue SMS 201-995 on hepatic haemodynamics in the pig and on intravariceal pressure in man. Br J Surg 1985; 72: 1009-1012. 22 Kleber G, Sauerbruch T, Fischer G, Paumgarmer G. Erh6hung des transmuralen Osophagusvarizendruckes unter Somatostatin-, nicht unter Placebo-Infusion [Abstract]. Gastroenterol 1987; 25: 40.
131
23 Staritz M, Rambow A, Manns M, Meyer zum Btischenfelde K-H. Effect of glycylpressin on the pressure in esophageal varices of patients with cirrhosis of the liver and previous variceal bleeding. Deutsche Med Wochenschr 1987; 112: 1292-1295. 24 Jenkins SA, Baxter JN, Corbett W, et al. A prospective randomised controlled clinical trial comparing somatostatin and vasopressin in controlling acute variceal haemorrhage. Br Med J 1985; 290: 275-278. 25 Walker S, Stiehl A, Raedsch R, et al. Terlipressin in bleeding oesophageal varices: a placebo-controlled, doubleblind study. Hepatology 1986; 6:112-115.
Journal of Hepatology, 1988; 7:126-131 Elsevier
HEP 00433
Leader
The endoscopic measurement of intravascular pressure and flow in oesophageal varices
M. S t a r i t z a n d K . - H . M e y e r z u m B i i s c h e n f e l d e I. Medizinische Klinik und Poliklinik, Johannes-Gutenberg Universitiit, Mainz (F. R. G. )
Introduction
Endoscopic
pressure
measurement
-
different
methods
Several new techniques to investigate the portal hypertensive patient have been described in recent years. Pressure and flow measurements in oesophageal varices obtained endoscopically have gathered Widespread attention as reflected by numerous current papers. Intraoesophageal pneumatic pressure sensoring by using a pneumatic pressure capsule, direct intravariceal fine needle puncture with or without perfusion of the needle, as well as endoscopic Doppler ultrasonography have been introduced to further elucidate the pathophysiology of portal hypertension, and the effect of several physiological parameters and drugs on oesophageal variceal pressure has been studied. New methods are important only if they provide insight into the pathophysiology of portal hypertension, or if they lead to new therapeutic approaches. The following article emphasizes the different techniques of flow and pressure measurement in oesophageal varices, presents the results obtained, and discusses their presumed clinical value.
Endoscopically guided variceal puncture Puncture of oesophageal varices was first performed by Palmer during rigid oesophagoscopy under general anaesthesia [1,2]. This procedure did not gain acceptance, since general anaesthesia and rigid endoscopy were too invasive to use for studies. Additionally, effects of general anaesthesia on portal hypertension could not be ruled out. Recently, however, variceal fine needle puncture has been reported as a simple approach for the measurement of intravariceal pressure [15]. After intravenous premedication with diazepam the patients underwent flexible oesophagoscopy by a standard technique. During continuous endoscopic observation variceal columns were punctured 5-10 cm above the cardia with a fine needle having an outer diameter of 0.71 mm. The very thin capillary lumen of this needle requires perfusion by a capillary hydraulic perfusion pump [3]. A pressure transducer attached to the perfusion system allows the pressure at the tip of the
Correspondence: M. Staritz, M.D., P.D., I. Medizinische Klinik und Poliklinik, Johannes-Gutenberg-Universit~it, Langenbeckstr. 1, D-6500 Mainz, F.R.G.
0168-8278/88/$03.50 © 1988 Elsevier Science Publishers B.V. (Biomedical Division)
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
PERFUSION
PUMP
WRI TER
-
-
ENDOSCOPE
-
-
VARIX
-
-
OESOPHAGUS
-
-
FINE NEEDLE
127
(Fig. 2) is fixed on the tip of the endoscope. An elastic membrane, which is part of the device, touches and slightly compresses the varix wall. Continuous insufflation of air into the capsule (Fig. 2) serves for maintaining the pressure in the capsule. When applied to a varix the pressure acting on the flexible membrane of the gauge stops air circulation. The pressure in the circuit then increases until it equals the pressure applied onto the membrane. Theoretically the pressure required for maintenance of air circulation equals that in the varix. According to this assumption pneumatic pressure sensoring can be used for indirect assessment of the pressure in varices [8,9]. A similar device in which air insufflation is provided by a constant flow has been introduced recently [10]. Neither, however, is yet available commercially.
Comparison of the methods
Fig. 1. Scheme of endoscopically guided variceal fine needle puncture. needle to be obtained (Fig. 1). Intravascular oesophageal variceal pressure (IOVP) is defined as the gradient between intravariceal and intraoesophageal pressure, the latter serving as zero-reference. A similar puncture method but without perfusion of the needle has been used by other investigators [5-7]. This technique comprises some disadvantages; e.g., the sensitivity for pressure alterations is lower and it is difficult to recognize a paravasal needle position. Additionally, in most patients the larger needle diameter requires variceal sclerosing therapy after the pressure measurements. Since most authors do not perform prophylactic sclerosing therapy they could not investigate patients without previous variceal haemorrhage.
Pneumatic pressure sensor
The pneumatic pressure sensor method also requires flexible oesophagoscopy. The pressure device
The variceal puncture technique is easy to perform and the pressure values are reproducible [4]. However, the procedure is in.vasive. Pressure monitoring using a pneumatic pressure sensor is less invasive. A comparison of both methods demonstrated that the pneumatic pressure sensor is suitable-only for patients with large varices (grade 11I and IV). With smaller varices (grade I and II) this technique is difficult to perform and the pressures obtained are not
4
tII: f
/'Varicosity Fig. 2. Scheme of the pneumatic pressure sensor. Its working principle: part of the pressure device is a flexible membrane which is positioned onto the varicosity. The capsule is perfused with air (e = flow into the capsule, i and h = recirculation). After compression of the flexible membrane by the variceal wall, pressure in the capsule, maintained by a compressor (d), rises until it equals that in the varix. This pressure is depicted on a manometer (c).
128
M. STARITZ AND K.-H. MEYER ZUM BOSCHENFELDE
representative due to artefacts caused by movement of the patients, peristalsis of the oesophagus and deviation of the pressure capsule from the variceal wall [10,11].
Assessment of flow in oesophageal varices Very few papers dealing with the measurement of flow in oesophageal varices are available. McCormack and co-workers [12,13] used a Doppler probe which is so small that it can be advanced through the channel of a normal flexible endoscope, working similarly to the transabdominal probe [14]. This method is based on the principle that ultrasonic waves with defined wavelengths are reflected by blood cells. This causes modulation of the wavelength depending on the velocity of passing erythrocytes (Doppler effect). The difference between the wavelength transmitted and received allows an estimation of direction and velocity of blood flow in varices.
Results obtained by the different techniques • Portal hypertension physiology
Several data concerning the pathophysiology of
Vances grade II 32-
I
Vor,ces grade Ill
I
!
2L]Z
E 16E
8-
157z06 227±2L IOVP Basal
& IOVP
31 0_'15 373zlL IOVP Valsolva
Fig. 3. Correlation between intravascular oesophageal variceal pressure and size of oesophageal varices under basal conditions and during Valsalva's manoeuvre. No difference in relative pressure elevation (A IOVP) was observed (grade 11 13.6 + {).8vs. grade III 13.5 + 1.5 mmHg).
portal hypertension and pharmacological effects on portal pressure have been obtained in recent years. It has been demonstrated [4,15] that in different varices of an individual patient the pressure is nearly identical. Therefore, repeated measurement in different varices to obtain the IOVP of an individual patient is not necessary. In different patients, however, the pressure in small varices is generally lower than in large varices (Fig. 3). This was the common finding of several authors [4,6,7,9,10]. Of particular interest was the question of the role of variceal pressure in the development of variceal haemorrhage. One of our follow-up investigations of patients who had previously undergone a shunt operation showed that individual patients with sufficient shunt could be easily identified by a decrease of variceal size from grade lIl to grade 1, accompanied by a significant decrease of variceal pressure [15]. In contrast, patients who rebled after a shunt operation had newly developed varices, the pressure and size of which were found to be similar to those values obtained before the shunt operation. Another study included 29 patients with histologically proven cirrhosis (Child A). Sixteen had recently bled from their varices, 13 had not. In all subjects variceal size had been classified endoscopically. Grade 1, II and IIl varices were found in 0, 6 and 10 patients, respectively, with recent haemorrhage, but only in 2, 9 and 2 patients, respectively, without previous bleeding. Variceal pressure of the bleeders amounted to 27 _+ 3.5 mmHg and to 16.5 _+ 1.8 mmHg in the non-bleeder group (Fig. 4) [16,17]. These findings were confirmed by Gross and Erhard [7]. The same authors tried to classify patients with recent haemorrhage according to their IOVP. In subjects with early relapsing haemorrhage, variceal pressure was significantly higher (37.5 mmHg) than in patients with late relapse (27.5 mmHg) or in those without further rebleeding (24.5 mmHg). These results support the opinion that variceal pressure could be a potential risk factor for the development of variceal haemorrhage. It raises the question as to which physiological parameters potentially influence variceal pressure. It has been demonstrated that intraabdomina[
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
phalad direction. Flow increased during inspiration and decreased during expiration. In some patients, however, flow occurred in both directions. The authors also performed recordings under general anaesthesia with positive pressure ventilation. Under these conditions, the direction of total flow became caudal in certain varices, decreasing during inspiration. This observation suggests the presence of perforating or communicating veins. Postmortem dissection confirmed the presence of large perforating veins in one of the patients investigated. Since flow monitoring identified perforating veins, the authors concluded that an ultrasonic Doppler probe should be a reliable aid for successful endoscopic sclerotherapy when injecting the sclerosants into the perforating veins.
mmH9 i 40-
35
•
129
O
25
Pharmacological studies
0
I
'
II
'ui'nvll a
•
I
'
II
~ I I I ~ I V I[
I
~
II
b
~ III ' IV I
o
c
Fig. 4. Con]parison of the variceal prcssur¢ in palients with rcccnl variccal hacmorrhagc who dcvclopcd early (c), late (b) or
no further reblceding (a). pressure elevation causes significant elevation of the pressure in the varices. One of our investigations [4] demonstrated that Valsalva's manoeuvre increased the variceal pressure by approximately 15 mmHg (Fig. 3). Similar findings were reported by Hosking et al. [18], whilst Schneider and Lackner [6] observed a pressure elevation up to 75 mmHg. Similar values were obtained during deep inspiration and expiration [6]. Another study was performed to elucidate the effect of body position on variceal pressure [19]. Pressures were measured in the horizontal position and during deviation by 30 ° either with feet down or head down. Since no significant pressure changes were obtained, the results suggest that body position does not affect variceal pressure. Very little information is available concerning the flow in varices. McCormack et al. [12,13] observed in 18 patients that blood in the varices flowed in a ce-
Several data suggest that variceal pressure is one of the main risk factors for the development of variceal bleeding. Most of.the pharmacological studies, therefore, had the aim of elucidating the effect of drugs that presumably lower variceal pressure. Nitroglycerin has been studied by two groups; according to their results the effect of the drug seems to depend on the molecular structure of the nitroglycerin type used. Glyceryl trinitrate ( 1.2 rag), having a short half life (5-11) rain) due to first-pass inactivation in the liver, causes a significant decrease of variceal pressure when applied sublingually [4]. In contrast, isosorbide dinitrate applied endoscopically into the duodenum had no effect on variceal pressure, although systemic pressure was decreased [20]. Somatostatin was investigated by three groups. Jenkins et al. [21] found a significant decrease of variceal pressure by approximately 509'o of the basal value after administration of somatostatin. Our group and Kleber et al. [22] were not able to confirm this effect. The different schedules of administration, particularly the simultaneous commencement of bolus injection and somatostatin perfusion may, to some extent, explain these contradicting results. Glycylpressin was also tested. The effect on intra-
130
M. STARITZ AND K.-H. MEYER ZUM BUSCHENFELDE
variceal pressure was less p o t e n t than e x p e c t e d . O n l y
t e c h n i q u e s are c o n s i d e r e d to be r e f e r e n c e m e t h o d s
in a p p r o x i m a t e l y o n e third of the p a t i e n t s was the
for the r e c e n t l y d e v e l o p e d n o n - i n v a s i v e p r o c e d u r e s .
variceal p r e s s u r e l o w e r e d , by only 3 - 5 m m H g [23].
T h e latter, h o w e v e r , have p r o v e n to be a reliable al-
This u n e x p e c t e d result might explain c o n t r a d i c t i n g
t e r n a t i v e only in patients with large varices. T h e re-
results of clinical trials which did not really p r o v e the
suits r e p o r t e d so far s u p p o r t the a s s u m p t i o n that in-
beneficial effect of terlipressin in variceal h a e m o r -
travariceal pressure is one of the m a j o r risk factors
rhage [24,25].
for the d e v e l o p m e n t of variceal bleeding. F u r t h e r m o r e , there is a strong positive c o r r e l a t i o n b e t w e e n pressure and size of varices. T h e study of physiologi-
Conclusion and perspectives
cal p a r a m e t e r s and drugs influencing portal h y p e r tension is of particular interest and the effect of drugs
E n d o s c o p i c m e a s u r e m e n t s of flow and p r e s s u r e in
that p r e s u m a b l y l o w e r i n t r a v a r i c e a l p r e s s u r e can be
o e s o p h a g e a l varices are new t e c h n i q u e s p r o v i d i n g
verified
f u r t h e r insight into the p a t h o p h y s i o l o g y of portal hy-
could help to plan f u r t h e r clinical trials including
pertension.
drugs which are c o n s i d e r e d to be beneficial in pa-
Several
invasive
and
non-invasive
m e t h o d s are in use for the m e a s u r e m e n t of variceal pressure.
directly.
These
pressure
measurements
tients with portal h y p e r t e n s i o n .
U p to n o w the invasive direct p u n c t u r e
References 1 Palmer ED. On correlations between portal venous pressure and size and extent of oesophageal varices in portal cirrhosis. Ann Surg 1953: 138: 741-744. 2 Palmer ED, Brick IB. Correlation between the severity of oesophageal varices in portal cirrhosis and their propensity toward hemorrhage• Gastroenterology 1956; 30: 98-90. 3 Arndorffer RC. Steff J J, Dodds W J, et al. Improved infusion system for intraluminal oesophageal manometry. Gastroenterology 1977; 24: 7-23. 4 Staritz M, Poralla T, Meyer zum Bfischenfelde K-H. Intravascular oesophageal variceal pressure (IOVP) assessed by endoscopic fine needle puncture under basal conditions, Valsalva's manoeuvre and after glyceryltrinitrate application. Gut 1985; 26: 525-530. 5 De Reuck M, Burette A, Van Gossum M, eta[. Endoscopic measurement of the pressure in the oesophageal varices of cirrhotic patients. Correlation with portal pressure. Acta Endosc 1984; 14: 121-127. 6 Schneider B, Lackner K. Pathogenese der Osophagusvarizenblutung. Deutsche Med Wochenschr 1986; 116: 611-615. 7 Gross E, Erhard J. Endoskopisch gefiihrte Druckmessung in distalen Osophagusvarizen. Deutsche Med Wochenschr 1987; 112: 125-127. 8 Mosimann R. Nonaggressive assessment of portal hypertension using endoscopic measurement of varicea[ pressure. AmJ Surg 1982: 143: 212-214. 9 Gertsch P, Meister JJ. Pressure measurement in oesophageal varices: preliminary report on a new non-invasive method. Gut 1988; in press. 10 Bosch J, Bordas JM, Rigau J, Viola C, et al. Noninvasive measurement of the pressure of oesophageal varices using
11
12
13 14
15
16
17
18
19
an endoscopic gauge: comparison with measurements by varicea[ puncture in patients undergoing endoscopic sclerotherapy• Hepatology 1986; 6: 667-672. Staritz M, Gertsch P. Pressure measurements in oesophageal varices: first comparison of two techniques. Endoscopy 1986~ 18: 253-254. McCormack T, Smallwood RH, Walton L, et al. Doppler ultrasound probe for assessment of blood-flow in oesophageal varices. Lancet 1983: i: 677-678. McCormack T, Smith PM, Rose JD, et al. Perforating veins and blood flow in oesophageal varices. Lancet 1983; ii: 1442-1444. Ohnishi K, Saito M, Koen H, et al. Pulsed doppler flow as a criterion of portal venous velocity: comparison with cineangiographic measurements. Radiology 1985; 154: 495-498. Staritz M, Meyer zum Bfischenfelde K-H. Endoscopic measurements of intravascular pressure and flow in blood vessels of the gastrointestinal tract. Clin Gastroenterol 1986; 15: 235-247. Staritz M, Manns M. Poralla T, et al. A new method for measurement of the intravascular oesophageal variceal pressure (IOVP) and assessment of IOVP in cirrhotic patients with and without recent variceal haemorrhage [Abstract]. Gastroenterology 1985; 88: 1697. Staritz M, Poralla T, Ewe K, et al. Endoskopische Bestimmung des Osophagusvarizendruckes (Endoscopic assessment of the oesophageal variceal pressure). Schweiz Rundsch Med Prax 1984; 38:1151-1152. Hosking SW, Robinson R, Johnson AG. Effect of Valsalva's manoeuvre and hyoscinbutylbromide on the pressure gradients across the wall of oesophageal varices. Gut 1987: 28: 1151-1156. Staritz M, Rambow A, Manns M, Meyer zum Bfischenfelde
PRESSURE AND FLOW MEASUREMENT IN OESOPHAGEAL VARICES
K-H. The effect of body position on the pressure in oesophageal varices [Abstract]. Gastroenterology 1987; 92: 1782. 20 Dawson J, West R, Gertsch P, et al. Endoscopic variceal pressure measurements: response to isosorbite dinitrate [Abstract]. Gut 1983, 24: 971. 21 Jenkins SA, Baxter JN, Corbett WA, Shields R. Effects of a somatostatin analogue SMS 201-995 on hepatic haemodynamics in the pig and on intravariceal pressure in man. Br J Surg 1985; 72: 1009-1012. 22 Kleber G, Sauerbruch T, Fischer G, Paumgarmer G. Erh6hung des transmuralen Osophagusvarizendruckes unter Somatostatin-, nicht unter Placebo-Infusion [Abstract]. Gastroenterol 1987; 25: 40.
131
23 Staritz M, Rambow A, Manns M, Meyer zum Btischenfelde K-H. Effect of glycylpressin on the pressure in esophageal varices of patients with cirrhosis of the liver and previous variceal bleeding. Deutsche Med Wochenschr 1987; 112: 1292-1295. 24 Jenkins SA, Baxter JN, Corbett W, et al. A prospective randomised controlled clinical trial comparing somatostatin and vasopressin in controlling acute variceal haemorrhage. Br Med J 1985; 290: 275-278. 25 Walker S, Stiehl A, Raedsch R, et al. Terlipressin in bleeding oesophageal varices: a placebo-controlled, doubleblind study. Hepatology 1986; 6:112-115.