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Controlled continuous flow (CCF) Resectoscope
CONTROLLED
CONTINUOUS
FLOW (CCF)
RESECTOSCOPE Report of 200 Cases JERROLD
WIDRAN,
From the Department Chicago, Illinois
M.D. of Urology, Chicago Medical School,
ABSTRACT-Controlled continuous flow (CCF) is a new balanced pumping system which has been designed for the resectoscope. The system is controlled by an intravesical pressure sensor. Upper limits of pressure are set, and the input flow is shut off electronically if it is attained. Flow rates of up to 1,000 ml/minute can be achieved for maximum clarity of vision. Two hundred cases have been performed with the CCF resectoscope. Various parameters were measured and are presented. The results indicate that TURP can be performed safely and more efficiently with the CCF reset toscope.
The options for irrigation in performing transurethral resection are interrupted flow (Fig. 1); suction continuous flow, Iglesias type (Fig. 2); and cystostomy continuous flow, Reuter type (Fig. 3). The most familiar resectoscope utilizes interrupted flow. Cutting and fulguration are done during the inflow of fluid. Flow rates are determined by the height of the fluid source, which can be controlled by manually elevating the bags of fluid. Maximum filling of the bladder prior to emptying is determined by the experience of the surgeon. Better visualization of arterial bleeding by increasing flow rates is frequently counter productive because the bladder fills faster, reaching capacity rapidly. This exposes the patient to potentially high intravesical pressure and increased absorption risks. Iglesias introduced the method of continuous flow, with a suction device attached to the out-
flow chamber; however, gravity is the means of delivery of the fluid. A crude method for attempting to balance the system plus no accurate means to determine when the bladder is full are undesirable features. Additionally, a design flaw allows air into the system, causing bubbles which are disturbing.
T.U.R. IRRIGATING SYSTEM RECIPROCAL GRAVITY IN--*GRAVITY OUT
FIGURE 1. Cut and fulgurate on input. Flow rates determined by height of fluid source. Problems related to bleeding and height of ceiling determine maximum flow rate that can be achieved-although hand pump can be attached to input if necessary.
242
UROLOGY
/ MARCH1985
/ VOLUMEXXV,NUMBER3
T.U.R.
IRRIGATING
CONTINUOUS GRAVITY
T.U.R.
SYSTEM
FLOW-IGLESIAS IN+
SUCTION
TYPE
IRRIGATING
CONTROLLED
OUT
PUMP UNDER I NTRAVESICAL
Gravity method of delivery. Crude FIGURE 2. method used for attempting to balance system; no accurate means to determine when bladder is full.
SYSTEM
CONTINUOUS IN-PUMP CONTROL PRESSURE
FLOW OUT OF SENSOR
E=3-
1
Balanced pumping system under control of intravesical pressure sensor. Flow rates up to 1,000 ml/minute can be achieved if necessary to visualize bleeders, for easy fulguration control. Constant intravesical pressure monitoring. Input pump shut off at predetermined maximum pressure. Maximum safety and efficiency. FIGURE 4.
T.U.R. CONTINUOUS GRAVITY
IRRIGATING
SYSTEM
FLOW-REUTER IN --*
SUCTION
TYPE OUT
CYSTOSTOMY
FIGURE 3. Gravity inflow. Trochar placed suprapubically. Potential dislodgement of trochar during surgery and difficulty at replacement. Fluid leakage around trochar. Working with collapsed bladder requires adjustments in technique. Potential outflow obstructions from pieces of tissue.
Reuter, in Germany, placed a trochar suprapubically and connected a suction to the outflow for a continuous system, again, with gravThis system requires ity inflow problems. surgical invasion with a trochar which could be dislodged during the operation and would be difficult to replace. In addition, there is potential for fluid leakage and a collapsed bladder. A possibility of outflow obstruction exists due to the direction of fluid movement. The tissue would be in the mainstream of flow. A controlled continuous flow (CCF) system has been developed to resolve some of the problems encountered in the previous techniques (Fig. 4). This instrument allows for continuous flow of fluid under the guidance of a pressure
UROI.O(:Y
M,4RCH 1985
Il VOI,UELlEXX\‘. NUMBER 3
transducer with accurate monitoring of the intravesical pressure in centimeters of water. Flow rates of up to 1,000 ml per minute may be obtained with a pumping system that is regulated to stop the fluid input when a predetermined pressure unit is attained. Resected tissue is evacuated at the end of the operation. Multiple design changes were necessary. Annoying bubbles were a solvable problem. Bleeding problems are overcome by increasing flow rates through rheostat control of the pumping system. A pressure transducer is designed into the instrument and measures intravesical pressure in centimeters of water throughout the surgical procedure. If the outflow becomes obstructed or the pumps are not balanced and there is a pressure buildup, the inflow pump will automatically stop at a predetermined pressure. Material and Methods Two hundred consecutive patients in two Chicago community hospitals were operated on for prostatic obstruction over a period of two and one-half years. The CCF system was used as a means of fluid delivery during the procedures. All operations were performed by the author.
243
TABLE I.
TABLE II.
Weight of tissue removed
Amount of Tissue (Gm)
% of Subjects (N = 200)
7-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-100 101-110 111-120
7 31 20 17 7 10 5 1 1 0 0 1
The potential risks of hypervolemia were monitored intravascularly with central venous pressure measurements and by comparing preoperative and postoperative serum sodium. The first measurement done after passing the instrument into the bladder is that of bladder capacity under anesthesia. The transducer is activated and fluid is infused from a neutral source to 40 cm of water pressure, arbitrarily chosen as the maximum safe pressure that should be obtained prior to shutting off the input pump.The neutral fluid source is a gravity bag of 1.5 per cent glycine. The following parameters were additionally recorded: hemoglobin changes, volume of tissue removed, volume of irrigating solution used, length of surgery, and length of hospital stay. Results Two hundred patients participated in this study; 178 had benign prostatic hypertrophy, and the remaining 22 cases involved carcinoma of the prostate. The patients ranged in age from forty-nine to ninety-four years, with a median of sixty-seven years. Spinal anesthesia was given in 143 cases; the other 57 received general anesthesia. The weight of tissue removed ranged from 7 to 120 Cm. The majority of the cases (75 % ) involved removal of 7 to 40 Cm of tissue. The overall weight distribution of the resected tissue is shown in Table I. These data are important to examine in relation to the length of the operation and irrigating fluid volume. The generalization that the smaller the gland, the-shorter the surgical procedure and the less irrigation fluid, seems to be accurate.
241
Length
of surgery % of Subjects
No. of Minutes
(N = 200)
20-29 30-39 40-49 50-59 60-69
47 17 18 13 5
TABLE III.
Volume of irrigating
Amount of Fluid (ml) (1.5 % Glycine) 9,000-10,000 lO,OOl-20,000 20,001-30,000 30,001-40,000 40,001-50,000 50,001-60,000
fluid
used
% of Subjects (N = 200) 3 75 18 3 0 1
The length of the surgery ranged from twenty to sixty-nine minutes. Most of the cases (64%) required between twenty to forty minutes to perform. Only 5 per cent of the cases required an hour or more (Table II). Resection time or, more specifically, grams resected per minute of time, ranged from 1 to 1.5 Gm. Variation in vascularity is an important factor to consider when examining the length of time necessary to perform a surgical procedure; however, these data are impossible to quantify. The volume of irrigating fluid used ranged from 9,000 to 60,000 ml. Only 2 per cent of the cases required less than 10,000 ml of fluid. The vast majority (93%) required between 10,000 and 30,000 ml of fluid (Table III). The length of hospital stay was recorded beginning with the day of surgery. The length of hospitalization from surgery to discharge ranged from four to twenty-three days. Of the total group, 92 per cent were discharged within ten days. The overall distribution is presented in Table IV One patient died three weeks after the procedure due to metastatic anaplastic carcinoma. Two other patients required prolonged hospital stay, 1 due to the development of vasitis and the other for lymph node staging. Hemoglobin determinations immediately postoperative were compared with preoperative levels in an effort to estimate blood loss. This is a very basic form of measurement because of the number of potential intervening variables, including the dilutional factor from fluid absorption. In 29 per cent of the cases
UROLOGY
/ MARCH 1985 / VOLUME XXV, NUMBER 3
Length of hospitalization from surgery to discharge
TABLE IV.
TABLE VI.
Bladder capacity under anesthesia
Number of Davs
% of Subjects (N = 200)
Amount of Fluid (ml)
% of Subjects (N = 200)
4 5-7 S-10 11-13 14-16 17-19 20-22 23
5 42 45 5 1 0 1 1
100-199 200-299 300-399 400-499 500-599 600-699 700-799 800-899 900-999
6 22 20 38 5 5 3 0 1
TABLE V.
Hemoglobin
dijjerence
after TUR % of Subjects (N = 200)
Hb. (Gm)
29 62 7 2
there was less than 1 Gm difference
and 91 per cent had a 2 Gm or less difference in levels postoperatively (Table V). Two patients received two units of packed blood cells each. The bladder capacity under anesthesia ranged from 100 to 1,000 ml of fluid. In 86 per cent of the cases 500 cc of fluid or less were required to reach the 40 cm of water pressure threshold. However, in 6 per cent of the cases only 100 to 200 cc of fluid were necessary to reach this threshold, while 4 per cent of the cases required as much as 700 ml or more of fluid to obtain this same pressure (Table VI). Sodium levels were drawn postoperatively to determine the potential problem with hyponatremia (Table VII). This is a major concern since hypervolemia and the concomitant hyponatremia can result in the potentially fatal TUR syndrome. In 35 per cent of the cases postoperative sodium levels were 140 mEq/L or greater, while 61 per cent ranged between 130 to 140 mEq/L. Only 4 per cent dropped below 130 mEq/L. Central venous pressure (CVP) was monitored in 90 per cent of the cases in this study. The CVP line was not inserted in 10 per cent of the cases for technical reasons. A CVP change of 15 cm of water was considered significant although clinical manifestations of water intoxication did not manifest before pressures of over 22 cm of water were reached. Twenty mg of furosemide (Lasix) was given intravenously
URO1,OC-f
MARCH1985
/ VOLUME
XXV. NUMBER3
TABLE VII.
Sodium level after TUR % of Subjects (N = 200)
Sodium Level (mWL)
35 61 4
> 140 130-140 < 130
when the CVP increased to 15 cm of water. In 20 per cent of the cases CVP elevations of 15 cm of water were observed. Furosemide was generally effective in controlling this pressure change. Most of the cases (80 % ) did not require intervention because the CVP remained at or below 15 cm of water throughout the procedure. In those cases which demonstrated significant CVP elevations, the rise occurred toward the end of the procedure when venous sinuses were exposed. The intravesical pressure receded when the intraprostatic pressure was discontinued. There were 2 patients who demonstrated clinical manifestations of hypervolemia. In one, nausea and hypertension with a CVP elevation of 26 cm of water and a sodium depression of 124 mEq/L developed. This problem was corrected with 20 mg of furosemide and discontinuation of the procedure. The other patient, under spinal anesthesia, became mentally confused and agitated; CVP measured 23 cm of water and the sodium was 127 mEq/L. In this case 200 ml of sodium chloride (3 % ) was used to correct the problem. Both patients had an uneventful postoperative recovery. Comment In the presentation of any new system there are three important questions to be answered: Is it safe? Does it work? Is it better than the present system being used? Safety is related to
245
blood loss, time exposed to the surgical procedure, absorption of irrigating fluids, postoperative morbidity and mortality, and length of hospitalization due to problems related to the surgical procedure. The data from this study indicated that all of these parameters varied within normal limits. Hemoglobin levels are, at best, a gross estimate of blood loss. More sophisticated means of determining this will be accomplished in future studies. However, the figures are certainly in the range established by Abrams and associates and Stephenson. In IO per cent of the cases there was a prolonged period of bleeding, requiring that a catheter be left in place for a longer duration of time. This could be due to the possibility that a more thorough resection was performed as a result of the CCF resectoscope and more venous sinuses were opened, causing the increased bleeding. The relationship of absorbed glycine to coagulopathy also requires consideration. The overall results of the study indicate that the CCF resectoscope is safe. There were no postoperative deaths related to the new system and no significant morbidity regardless of the fact that the advanced age group of the patients in this population places them at risk. The CCF resectoscope has passed the government regulations for general clinical usage. Food and Drug Administration approval has been granted. One of the most important safety factors to consider is the relationship of constant fluid flow to absorption. Theoretically, continuous flow techniques should minimize the absorption of irrigation fluid since it is feasible to maintain a constant low prostatic pressure throughout the resection. Stephenson and associates, Bird and associates, Gellman, and Notley all suggest this and discuss the possibility that the incidence of the TUR syndrome, which is responsible for a number of deaths, might be reduced by resectoscopes which utilize a continuous flow system. Each time the interrupted fluid system was evaluated, intravesical pressures up to 100 cm of water have been measured just prior to emptying the bladder. This is most critical in the latter part of the operation if venous sinuses are opened. At that time one does not want to exceed low pressures to force fluid into the venous system when there is a high risk for hypervolemia and all of its clinical implications. Examination of the CVP change data in this study is inconclusive due to the fact that this
246
variable had never been measured previously in routine TURs. One would expect that the CCF resectoscope would be safer in this respect because intravesical pressure changes can be maintained within specified limits. This is a great advantage of this instrument over the present method. Although CVP measurements are important in other surgical procedures, the anesthesiologists were reluctant to add their invasive procedure to the protocol. An accurate noninvasive measurement of blood volume changes is necessary before this monitoring can be included in the routine protocol for TURs. Thoracic impedance has been suggested by Casthely and associates and will be evaluated. In addition, dopplers will be considered. With this new procedure there are new questions to consider. The volume of fluid necessary to increase bladder pressure to 40 cm of water under anesthesia has not been measured before because an intravesical pressure transducer had never been designed into an instrument used to perform surgery on the prostate. Now not only is it possible for the surgeon to have this information, it is available to him throughout the resection. This is very beneficial to the surgeon. In addition, the inflow pump will automatically shut off when a predetermined pressure threshold is reached. This pressure threshold is adjustable; however, it appears desirable never to exceed an accurately measured pressure of 40 cm of water during an operation. Perhaps this pressure is too high; perhaps 10 cm of water pressure should not be exceeded. Only by investigating many more procedures with the CCF resectoscope can this be adequately evaluated. Further study will be necessary to determine what specific safe range can be recommended to elicit adequate bladder distention, visibility, and minimal fluid absorption. The CCF resectoscope does function well. The instrument is no more cumbersome than an Iglesias continuous flow resectoscope. One extra port carries the 5-F pressure transducer. The console connections do require a short learning experience; however, the actual resection procedure remains unchanged. There is no longer the need for the nurse to change bags of fluid at the top of a stepladder. The question regarding the superiority of the CCF system over the interrupted flow system can be answered only subjectively at the present time. It is the opinion of the author, based on twenty-five years of clinical practice, that the
UROLOGY
/ MARCH
1985
/ VOLUME
XXV, NUMBER 3
111 North Wabash Chicago, Illinois 60602
CCF resectoscope can potentially reduce surgical time and increase the efficiency and safety of the TUR. Bird and associates, Gellman, and Notley have indicated these same benefits with a continuous flow type fluid system. There is no longer the obnoxious need for multiple interruptions of the surgical procedure for emptying the bladder. Pieces of resected tissue are evacuated at the end of the operation. The CCF resectoscope additionally offers high flow rates, up to 1,000 cc per minute, which improves the field of vision. Clarity of vision is related to the speed of the fluid over the blood vessel and location of the outflow system. These features are superior in the CCF resectoscope. This research was designed to evaluate the general safety of the CCF resectoscope. The instrument has been demonstrated to be safe for clinical use and has received FDA approval. Several potential advantages over the presently popular interrupted flow system have been identified. Two important issues have been raised which merit further investigation. Due to the pressure sensor designed into the instrument, the CCF resectoscope provides a means to further examine intravesical pressure changes during a TUR. This was not possible previously. The determination of a normal, safe surgical range would be very beneficial. Second, an issue of major consequence is in regard to perioperative blood volume changes. Should CVP monitoring be added to the standard TUR protocol or are there alternative, effective, noninvasive means available? The incidence of the TUR syndrome in general urologic practice is probably more common than the presently available data indicate. Regardless of what technique is utilized, a method of monitoring this parameter must be determined.
UROL,OGY
MARCH
1985
1 VOLUME
XXV. NUMBER
ACKKOWLEDCMENT. To Susan A. Goldstein, assistance in the preparation of this material tion.
M.S.N., for for publica-
Bibliography Abrams PH, et al: Forum: blood loss during transurethral resection of the prostate, Anaesthesia 37: 71 (1982). Bird D, Slade N, and Feneley RC: Intravascular complications of transurethral resection of the prostate, Br J Uro154: 564 (1982). Boyarsky S: Prevention of cautery burns during transurethral resection of prostate, Urology 20: 599 (1982). Casthely P, Ramanathan S, Chalson J, and Turndorf H: Decreases in electric thoracic impedance during transurethral resection of the prostate: an index of early water intoxication, J Urol 125: 347 (1981). Gellman AC: Endoscopic prostatectomy with the continuous flow resection technique, Internat Surg 65: 5 (1980). Hart AJ, and Fowler JW: Incidence of urethral stricture after transurethral resection of the prostate, Urology 18: 588 (1981). Harzmann R, Van Deyk K, Fluchter St-H, and Bichler KH: Perioperative noninvasive recognition of the TUR-syndrome in transurethral resections, Eur Urol 8: 216 (1982). Henderson DJ, and Middleton RG: Coma from hyponatremia following transurethral resection of the prostate, Urology 15: 267 (1980). Hoekstra PT, et al: Transurethral prostatic resection syndrome-a new perspective: encephalopathy with associated hyperammonemia, J Urol 130: 704 (1983). Iglesias JJ, Sporer A, Gellman AC, and Seebode JJ: New Iglesias resectoscope with continuous irrigation simultaneous suction and low intravesical pressure, ibid 114: 929 (1975). Logie JR, Keenan RA, Whiting PH, and Steyn JH: Fluid absorption during transurethral prostatectomy, Br J Urol 50: 526 (1980). Madsen PO, and Nabor KG: The importance of the pressure in the prostate fossa and absorption of irrigating fluid during transurethral resection of the prostate, J Ural 109: 446 (1973). Notley RG: Transurethral resection of the prostate with and without continuous irrigation, J R Sot Med 75: 871 (1982). Stephenson TP, et al: Comparison between continuous flow and intermittent flow transurethral resection in 40 patients presenting with acute retention, Br J Urol 52: 523 (1980). Widran J: Controlled continuous flow method for transurethral resection, Urology 21: 130 (1983).
3
247
CONTINUOUS
FLOW (CCF)
RESECTOSCOPE Report of 200 Cases JERROLD
WIDRAN,
From the Department Chicago, Illinois
M.D. of Urology, Chicago Medical School,
ABSTRACT-Controlled continuous flow (CCF) is a new balanced pumping system which has been designed for the resectoscope. The system is controlled by an intravesical pressure sensor. Upper limits of pressure are set, and the input flow is shut off electronically if it is attained. Flow rates of up to 1,000 ml/minute can be achieved for maximum clarity of vision. Two hundred cases have been performed with the CCF resectoscope. Various parameters were measured and are presented. The results indicate that TURP can be performed safely and more efficiently with the CCF reset toscope.
The options for irrigation in performing transurethral resection are interrupted flow (Fig. 1); suction continuous flow, Iglesias type (Fig. 2); and cystostomy continuous flow, Reuter type (Fig. 3). The most familiar resectoscope utilizes interrupted flow. Cutting and fulguration are done during the inflow of fluid. Flow rates are determined by the height of the fluid source, which can be controlled by manually elevating the bags of fluid. Maximum filling of the bladder prior to emptying is determined by the experience of the surgeon. Better visualization of arterial bleeding by increasing flow rates is frequently counter productive because the bladder fills faster, reaching capacity rapidly. This exposes the patient to potentially high intravesical pressure and increased absorption risks. Iglesias introduced the method of continuous flow, with a suction device attached to the out-
flow chamber; however, gravity is the means of delivery of the fluid. A crude method for attempting to balance the system plus no accurate means to determine when the bladder is full are undesirable features. Additionally, a design flaw allows air into the system, causing bubbles which are disturbing.
T.U.R. IRRIGATING SYSTEM RECIPROCAL GRAVITY IN--*GRAVITY OUT
FIGURE 1. Cut and fulgurate on input. Flow rates determined by height of fluid source. Problems related to bleeding and height of ceiling determine maximum flow rate that can be achieved-although hand pump can be attached to input if necessary.
242
UROLOGY
/ MARCH1985
/ VOLUMEXXV,NUMBER3
T.U.R.
IRRIGATING
CONTINUOUS GRAVITY
T.U.R.
SYSTEM
FLOW-IGLESIAS IN+
SUCTION
TYPE
IRRIGATING
CONTROLLED
OUT
PUMP UNDER I NTRAVESICAL
Gravity method of delivery. Crude FIGURE 2. method used for attempting to balance system; no accurate means to determine when bladder is full.
SYSTEM
CONTINUOUS IN-PUMP CONTROL PRESSURE
FLOW OUT OF SENSOR
E=3-
1
Balanced pumping system under control of intravesical pressure sensor. Flow rates up to 1,000 ml/minute can be achieved if necessary to visualize bleeders, for easy fulguration control. Constant intravesical pressure monitoring. Input pump shut off at predetermined maximum pressure. Maximum safety and efficiency. FIGURE 4.
T.U.R. CONTINUOUS GRAVITY
IRRIGATING
SYSTEM
FLOW-REUTER IN --*
SUCTION
TYPE OUT
CYSTOSTOMY
FIGURE 3. Gravity inflow. Trochar placed suprapubically. Potential dislodgement of trochar during surgery and difficulty at replacement. Fluid leakage around trochar. Working with collapsed bladder requires adjustments in technique. Potential outflow obstructions from pieces of tissue.
Reuter, in Germany, placed a trochar suprapubically and connected a suction to the outflow for a continuous system, again, with gravThis system requires ity inflow problems. surgical invasion with a trochar which could be dislodged during the operation and would be difficult to replace. In addition, there is potential for fluid leakage and a collapsed bladder. A possibility of outflow obstruction exists due to the direction of fluid movement. The tissue would be in the mainstream of flow. A controlled continuous flow (CCF) system has been developed to resolve some of the problems encountered in the previous techniques (Fig. 4). This instrument allows for continuous flow of fluid under the guidance of a pressure
UROI.O(:Y
M,4RCH 1985
Il VOI,UELlEXX\‘. NUMBER 3
transducer with accurate monitoring of the intravesical pressure in centimeters of water. Flow rates of up to 1,000 ml per minute may be obtained with a pumping system that is regulated to stop the fluid input when a predetermined pressure unit is attained. Resected tissue is evacuated at the end of the operation. Multiple design changes were necessary. Annoying bubbles were a solvable problem. Bleeding problems are overcome by increasing flow rates through rheostat control of the pumping system. A pressure transducer is designed into the instrument and measures intravesical pressure in centimeters of water throughout the surgical procedure. If the outflow becomes obstructed or the pumps are not balanced and there is a pressure buildup, the inflow pump will automatically stop at a predetermined pressure. Material and Methods Two hundred consecutive patients in two Chicago community hospitals were operated on for prostatic obstruction over a period of two and one-half years. The CCF system was used as a means of fluid delivery during the procedures. All operations were performed by the author.
243
TABLE I.
TABLE II.
Weight of tissue removed
Amount of Tissue (Gm)
% of Subjects (N = 200)
7-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-100 101-110 111-120
7 31 20 17 7 10 5 1 1 0 0 1
The potential risks of hypervolemia were monitored intravascularly with central venous pressure measurements and by comparing preoperative and postoperative serum sodium. The first measurement done after passing the instrument into the bladder is that of bladder capacity under anesthesia. The transducer is activated and fluid is infused from a neutral source to 40 cm of water pressure, arbitrarily chosen as the maximum safe pressure that should be obtained prior to shutting off the input pump.The neutral fluid source is a gravity bag of 1.5 per cent glycine. The following parameters were additionally recorded: hemoglobin changes, volume of tissue removed, volume of irrigating solution used, length of surgery, and length of hospital stay. Results Two hundred patients participated in this study; 178 had benign prostatic hypertrophy, and the remaining 22 cases involved carcinoma of the prostate. The patients ranged in age from forty-nine to ninety-four years, with a median of sixty-seven years. Spinal anesthesia was given in 143 cases; the other 57 received general anesthesia. The weight of tissue removed ranged from 7 to 120 Cm. The majority of the cases (75 % ) involved removal of 7 to 40 Cm of tissue. The overall weight distribution of the resected tissue is shown in Table I. These data are important to examine in relation to the length of the operation and irrigating fluid volume. The generalization that the smaller the gland, the-shorter the surgical procedure and the less irrigation fluid, seems to be accurate.
241
Length
of surgery % of Subjects
No. of Minutes
(N = 200)
20-29 30-39 40-49 50-59 60-69
47 17 18 13 5
TABLE III.
Volume of irrigating
Amount of Fluid (ml) (1.5 % Glycine) 9,000-10,000 lO,OOl-20,000 20,001-30,000 30,001-40,000 40,001-50,000 50,001-60,000
fluid
used
% of Subjects (N = 200) 3 75 18 3 0 1
The length of the surgery ranged from twenty to sixty-nine minutes. Most of the cases (64%) required between twenty to forty minutes to perform. Only 5 per cent of the cases required an hour or more (Table II). Resection time or, more specifically, grams resected per minute of time, ranged from 1 to 1.5 Gm. Variation in vascularity is an important factor to consider when examining the length of time necessary to perform a surgical procedure; however, these data are impossible to quantify. The volume of irrigating fluid used ranged from 9,000 to 60,000 ml. Only 2 per cent of the cases required less than 10,000 ml of fluid. The vast majority (93%) required between 10,000 and 30,000 ml of fluid (Table III). The length of hospital stay was recorded beginning with the day of surgery. The length of hospitalization from surgery to discharge ranged from four to twenty-three days. Of the total group, 92 per cent were discharged within ten days. The overall distribution is presented in Table IV One patient died three weeks after the procedure due to metastatic anaplastic carcinoma. Two other patients required prolonged hospital stay, 1 due to the development of vasitis and the other for lymph node staging. Hemoglobin determinations immediately postoperative were compared with preoperative levels in an effort to estimate blood loss. This is a very basic form of measurement because of the number of potential intervening variables, including the dilutional factor from fluid absorption. In 29 per cent of the cases
UROLOGY
/ MARCH 1985 / VOLUME XXV, NUMBER 3
Length of hospitalization from surgery to discharge
TABLE IV.
TABLE VI.
Bladder capacity under anesthesia
Number of Davs
% of Subjects (N = 200)
Amount of Fluid (ml)
% of Subjects (N = 200)
4 5-7 S-10 11-13 14-16 17-19 20-22 23
5 42 45 5 1 0 1 1
100-199 200-299 300-399 400-499 500-599 600-699 700-799 800-899 900-999
6 22 20 38 5 5 3 0 1
TABLE V.
Hemoglobin
dijjerence
after TUR % of Subjects (N = 200)
Hb. (Gm)
29 62 7 2
there was less than 1 Gm difference
and 91 per cent had a 2 Gm or less difference in levels postoperatively (Table V). Two patients received two units of packed blood cells each. The bladder capacity under anesthesia ranged from 100 to 1,000 ml of fluid. In 86 per cent of the cases 500 cc of fluid or less were required to reach the 40 cm of water pressure threshold. However, in 6 per cent of the cases only 100 to 200 cc of fluid were necessary to reach this threshold, while 4 per cent of the cases required as much as 700 ml or more of fluid to obtain this same pressure (Table VI). Sodium levels were drawn postoperatively to determine the potential problem with hyponatremia (Table VII). This is a major concern since hypervolemia and the concomitant hyponatremia can result in the potentially fatal TUR syndrome. In 35 per cent of the cases postoperative sodium levels were 140 mEq/L or greater, while 61 per cent ranged between 130 to 140 mEq/L. Only 4 per cent dropped below 130 mEq/L. Central venous pressure (CVP) was monitored in 90 per cent of the cases in this study. The CVP line was not inserted in 10 per cent of the cases for technical reasons. A CVP change of 15 cm of water was considered significant although clinical manifestations of water intoxication did not manifest before pressures of over 22 cm of water were reached. Twenty mg of furosemide (Lasix) was given intravenously
URO1,OC-f
MARCH1985
/ VOLUME
XXV. NUMBER3
TABLE VII.
Sodium level after TUR % of Subjects (N = 200)
Sodium Level (mWL)
35 61 4
> 140 130-140 < 130
when the CVP increased to 15 cm of water. In 20 per cent of the cases CVP elevations of 15 cm of water were observed. Furosemide was generally effective in controlling this pressure change. Most of the cases (80 % ) did not require intervention because the CVP remained at or below 15 cm of water throughout the procedure. In those cases which demonstrated significant CVP elevations, the rise occurred toward the end of the procedure when venous sinuses were exposed. The intravesical pressure receded when the intraprostatic pressure was discontinued. There were 2 patients who demonstrated clinical manifestations of hypervolemia. In one, nausea and hypertension with a CVP elevation of 26 cm of water and a sodium depression of 124 mEq/L developed. This problem was corrected with 20 mg of furosemide and discontinuation of the procedure. The other patient, under spinal anesthesia, became mentally confused and agitated; CVP measured 23 cm of water and the sodium was 127 mEq/L. In this case 200 ml of sodium chloride (3 % ) was used to correct the problem. Both patients had an uneventful postoperative recovery. Comment In the presentation of any new system there are three important questions to be answered: Is it safe? Does it work? Is it better than the present system being used? Safety is related to
245
blood loss, time exposed to the surgical procedure, absorption of irrigating fluids, postoperative morbidity and mortality, and length of hospitalization due to problems related to the surgical procedure. The data from this study indicated that all of these parameters varied within normal limits. Hemoglobin levels are, at best, a gross estimate of blood loss. More sophisticated means of determining this will be accomplished in future studies. However, the figures are certainly in the range established by Abrams and associates and Stephenson. In IO per cent of the cases there was a prolonged period of bleeding, requiring that a catheter be left in place for a longer duration of time. This could be due to the possibility that a more thorough resection was performed as a result of the CCF resectoscope and more venous sinuses were opened, causing the increased bleeding. The relationship of absorbed glycine to coagulopathy also requires consideration. The overall results of the study indicate that the CCF resectoscope is safe. There were no postoperative deaths related to the new system and no significant morbidity regardless of the fact that the advanced age group of the patients in this population places them at risk. The CCF resectoscope has passed the government regulations for general clinical usage. Food and Drug Administration approval has been granted. One of the most important safety factors to consider is the relationship of constant fluid flow to absorption. Theoretically, continuous flow techniques should minimize the absorption of irrigation fluid since it is feasible to maintain a constant low prostatic pressure throughout the resection. Stephenson and associates, Bird and associates, Gellman, and Notley all suggest this and discuss the possibility that the incidence of the TUR syndrome, which is responsible for a number of deaths, might be reduced by resectoscopes which utilize a continuous flow system. Each time the interrupted fluid system was evaluated, intravesical pressures up to 100 cm of water have been measured just prior to emptying the bladder. This is most critical in the latter part of the operation if venous sinuses are opened. At that time one does not want to exceed low pressures to force fluid into the venous system when there is a high risk for hypervolemia and all of its clinical implications. Examination of the CVP change data in this study is inconclusive due to the fact that this
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variable had never been measured previously in routine TURs. One would expect that the CCF resectoscope would be safer in this respect because intravesical pressure changes can be maintained within specified limits. This is a great advantage of this instrument over the present method. Although CVP measurements are important in other surgical procedures, the anesthesiologists were reluctant to add their invasive procedure to the protocol. An accurate noninvasive measurement of blood volume changes is necessary before this monitoring can be included in the routine protocol for TURs. Thoracic impedance has been suggested by Casthely and associates and will be evaluated. In addition, dopplers will be considered. With this new procedure there are new questions to consider. The volume of fluid necessary to increase bladder pressure to 40 cm of water under anesthesia has not been measured before because an intravesical pressure transducer had never been designed into an instrument used to perform surgery on the prostate. Now not only is it possible for the surgeon to have this information, it is available to him throughout the resection. This is very beneficial to the surgeon. In addition, the inflow pump will automatically shut off when a predetermined pressure threshold is reached. This pressure threshold is adjustable; however, it appears desirable never to exceed an accurately measured pressure of 40 cm of water during an operation. Perhaps this pressure is too high; perhaps 10 cm of water pressure should not be exceeded. Only by investigating many more procedures with the CCF resectoscope can this be adequately evaluated. Further study will be necessary to determine what specific safe range can be recommended to elicit adequate bladder distention, visibility, and minimal fluid absorption. The CCF resectoscope does function well. The instrument is no more cumbersome than an Iglesias continuous flow resectoscope. One extra port carries the 5-F pressure transducer. The console connections do require a short learning experience; however, the actual resection procedure remains unchanged. There is no longer the need for the nurse to change bags of fluid at the top of a stepladder. The question regarding the superiority of the CCF system over the interrupted flow system can be answered only subjectively at the present time. It is the opinion of the author, based on twenty-five years of clinical practice, that the
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CCF resectoscope can potentially reduce surgical time and increase the efficiency and safety of the TUR. Bird and associates, Gellman, and Notley have indicated these same benefits with a continuous flow type fluid system. There is no longer the obnoxious need for multiple interruptions of the surgical procedure for emptying the bladder. Pieces of resected tissue are evacuated at the end of the operation. The CCF resectoscope additionally offers high flow rates, up to 1,000 cc per minute, which improves the field of vision. Clarity of vision is related to the speed of the fluid over the blood vessel and location of the outflow system. These features are superior in the CCF resectoscope. This research was designed to evaluate the general safety of the CCF resectoscope. The instrument has been demonstrated to be safe for clinical use and has received FDA approval. Several potential advantages over the presently popular interrupted flow system have been identified. Two important issues have been raised which merit further investigation. Due to the pressure sensor designed into the instrument, the CCF resectoscope provides a means to further examine intravesical pressure changes during a TUR. This was not possible previously. The determination of a normal, safe surgical range would be very beneficial. Second, an issue of major consequence is in regard to perioperative blood volume changes. Should CVP monitoring be added to the standard TUR protocol or are there alternative, effective, noninvasive means available? The incidence of the TUR syndrome in general urologic practice is probably more common than the presently available data indicate. Regardless of what technique is utilized, a method of monitoring this parameter must be determined.
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ACKKOWLEDCMENT. To Susan A. Goldstein, assistance in the preparation of this material tion.
M.S.N., for for publica-
Bibliography Abrams PH, et al: Forum: blood loss during transurethral resection of the prostate, Anaesthesia 37: 71 (1982). Bird D, Slade N, and Feneley RC: Intravascular complications of transurethral resection of the prostate, Br J Uro154: 564 (1982). Boyarsky S: Prevention of cautery burns during transurethral resection of prostate, Urology 20: 599 (1982). Casthely P, Ramanathan S, Chalson J, and Turndorf H: Decreases in electric thoracic impedance during transurethral resection of the prostate: an index of early water intoxication, J Urol 125: 347 (1981). Gellman AC: Endoscopic prostatectomy with the continuous flow resection technique, Internat Surg 65: 5 (1980). Hart AJ, and Fowler JW: Incidence of urethral stricture after transurethral resection of the prostate, Urology 18: 588 (1981). Harzmann R, Van Deyk K, Fluchter St-H, and Bichler KH: Perioperative noninvasive recognition of the TUR-syndrome in transurethral resections, Eur Urol 8: 216 (1982). Henderson DJ, and Middleton RG: Coma from hyponatremia following transurethral resection of the prostate, Urology 15: 267 (1980). Hoekstra PT, et al: Transurethral prostatic resection syndrome-a new perspective: encephalopathy with associated hyperammonemia, J Urol 130: 704 (1983). Iglesias JJ, Sporer A, Gellman AC, and Seebode JJ: New Iglesias resectoscope with continuous irrigation simultaneous suction and low intravesical pressure, ibid 114: 929 (1975). Logie JR, Keenan RA, Whiting PH, and Steyn JH: Fluid absorption during transurethral prostatectomy, Br J Urol 50: 526 (1980). Madsen PO, and Nabor KG: The importance of the pressure in the prostate fossa and absorption of irrigating fluid during transurethral resection of the prostate, J Ural 109: 446 (1973). Notley RG: Transurethral resection of the prostate with and without continuous irrigation, J R Sot Med 75: 871 (1982). Stephenson TP, et al: Comparison between continuous flow and intermittent flow transurethral resection in 40 patients presenting with acute retention, Br J Urol 52: 523 (1980). Widran J: Controlled continuous flow method for transurethral resection, Urology 21: 130 (1983).
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