Vol. 118, July, Part 2 Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
THE LOCALIZATION OF INTRARENAL CALCULI DURING SURGERY WILLIAM H. BOYCE From the Section of Urology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina
ABSTRACT
This is a summary review of past and present technology for accurate anatomical localization of calculi within the surgically exposed kidney. The methodology is applicable to reconstructive renal surgery for pathological processes other than calculi. Like the beauty in nature some very important individuals are so close to us that they are taken for granted. As Editor of The Journal of Urology, founder of Urological Survey, teacher, leader, advisor and friend, Dr. Hugh J. Jewett has been such an individual to all urologists. His brilliant intellect has appeared in innumerable facets: incisive, analytical investigator; pioneering, meticulous surgeon; superb teacher; precise, demanding editor; wise and sympathetic counselor; humorist and raconteur. For all your many contributions to Urology and to urologists, we salute you, "Huey". A voluminous literature on the subject of this review dates from the second decade of this century to the present time. Clinical use and application appear to have lagged behind the technical advances in this field to a remarkable degree. 1 In simplistic terms the roentgenogram depicts relative differences in density along the path of the beam. Since all crystalline structures are of distinctly different density than that of living tissue it appears theoretically possible to identify within the exposed kidney any crystalline mass large enough to be visible to the unaided eye. The proper modification of the x-ray beam and the choice of film with appropriate qualities of resolution are the only requirements for success. The feasibility of achieving this was demonstrated clearly with equipment available in 1958 as used in the study of microscopic structure of native human calculi. 2 The purpose of this review is to summarize the historical developments as they relate to current technical capabilities and, thereby, to establish the fact that in this area of endeavor the theoretical is indeed capable of practical application. EQUIPMENT AND ENERGY SOURCES FOR IONIZING RADIATION
Fluoroscopy was one of the earliest techniques employed for this purpose. 3 Its utilization continued in pace with technological improvement in the equipment and, particularly, in display screens. 4 Intraoperative use of this technique with a considerable degree of success was reported in 1957. 5 The obvious advantage offluoroscopy is in the rapid localization of the stone as it relates to a metal pointer or other point of reference. Disadvantages of fluoroscopy relate to radiation hazards, the difficulty of manipulating C-arms in surgical fields, a lack of adequate resolution of small calculi and the expense of maintaining such equipment within the limited space of conventional surgical rooms. However, the technique continues to be of considerable importance in the cystoscopic extraction and surgical removal of ureteral calculi. i; The atomic age provided access to radioisotopes as sources for ionizing radiation. These offered the promise of highly mobile sterilizable units capable of introduction directly into the operative field. The surgical use of thulium 170 for this purpose was described by Burke. 7 Failure to use gamma rays probably relates to difficulty in adjustment of the field strength from the energy source, the expense of maintaining the equipment and, possibly, failure of commercial development. In any event, the technique is not of current practical importance.
Conventional portable x-ray tubes have been used in the operating rooms for purposes of localization of stones since the second decade of the century. 8• " Current models of the portable x-ray tube are available universally. They provide a maximum opportunity to modify the characteristics of the beam through appropriate adjustments of kilovolts peak, timing in milliseconds, collimation and adjustment of the size of the field. In all probability this type unit will remain the energy source of choice for some time to come. Ultrasonography, first utilized for intrarenal localization of calculi by Schlegel and associates in 1961 10 and currently undergoing continuing investigation, 11 • 12 may ultimately supplant ionizing radiation for this purpose. DISPLAY UNITS, FILM AND FILM HOLDERS
Flexible sterile holders. Conventional radiosensitive film in flexible sterile holders was the first recording graphic display unit used during surgery and continues to be the most widely used technique. Quinby wrapped his film in light-proof paper and, at the time of the operation, dropped the unsterile packets into previously sterilized rubber bags. 9 This basic technique is used today in our institution, when exceptionally large kidneys or exceptional problems of resolution require film packs that are not available commercially. The film of appropriate characteristics, such as high resolution industrial film or glass plate, is cut to the appropriate size and sealed in a single wrap of light-proof black paper, which is secured by cellulose or paper tape. The wrapped film is then placed in a bag of heavy plastic of appropriate size and sealed with heat. At the time of the operation the entire bag is sterilized by soaking in formaldehyde-hexachlorophene isopropanol solution. Any solution appropriate for cold sterilization is acceptable ifit is compatible with plastics. The plastic bags, so sealed, resist leakage even in boiling water. Bags and sealer are available at a modest cost in most hardware and department stores under the general category of food savers. The major disadvantage of flexible film is the distortion of the image and resultant surreptitious dislocation of the stone with respect to the renal outline. This problem has been solved by Spence who has advocated spot films of the kidney since 1962. "Bite-wing" dental film is wrapped in sterile paper and dental radiologic techniques are used to pinpoint the position of the stone. 13 Commercially prepared film in sealed plastic bags appropriate for cold sterilization are marked currently as Kodak Kidney Surgery Film. 14• * These films are of relatively small size, contain a notch to accommodate the renal pedicle and, recently, have included 2 sheets of film of different sensitivity so that relatively soft and hard radiograms.are obtained from a single exposure. Static electrical exposure may be a problem in the manipulation of any flexible film pack. Solid cassette holder. Beer introduced very thin aluminum cassettes made in the shape of the kidney and containing * Kodak X-Omat KS film, Eastman Kodak Company, Rochester, New York. 152
LOCALIZATION OF INTJRARENAL CALCULI DURING SURGERY
double intensifying screens much in the nature of available cassettes. 8 These were 3¼ by 4¼ inches in size dropped into a sterile rubber glove at the time These cassettes were in widespread use at this in the fifth decade and provided excellent definition of intrarenal calculi. Kodak the series of "M Plates" of type B panchroand high resolving power for use in photomiin the fifth and sixth decades. were 3¼ inches and were loaded easily 5 graphic plate-type cassettes, which were available 7-inch sizes for larger displays (fig. 1). The rigid the kidney to be applied against a srn.ooth, and reduced the distortion occasioned a relaflexible against a highly .. -"·"-··- film. These cassettes require sealing in leak-proof plastic and cold sterilization. Such high resolution plates provide superb definition of the smallest intrarenal collections of crystal and, indeed, surpass the resolving power of the normal human eye. Future developments in electronic imaging may obviate the use of film in surgery. For the present, however, the commercapable of providing clear definicially available film is tion of the and woof of ordinary cotton surgical tapes the kidney and of medicinal grade silicone inches outside diameter (fig. 2). localization of calculi. Available display techinformation in only 2 dimensions, To achieve a functional aspect of depth many types of markers have been The most widely used technique, introduced by in 1939, consisted of placing straight needles at as near the stone as possible and then obtaining exposures. 1' introduced a wire that ,nrv,vtn.-J the kidney in front of the x-ray film and provided recognizable nc.a,n·r,Q of grids whereby the stone could be respect to the margins of the kidney. 16 localized With the development of hypothermia and the demonstrable of approaching the renal pelvis and calices placed between the arterial segments of the it became advantageous to establish the relationship of the calculus-containing calix to these planes of approach. The arterial segments are defined first by intravenous administration of methylene while various arteries supplying the segments of the kidney are clamped selectively. The arterial segments, having been so defined, are then outlined by removing appropriate lengths of the radiopaque thread from surgical gauze sponges. The thread is held in place along the FIG. 2. Intraoperative radiograms. A, before small concretions appear to be within parenchyma kidney. Cassette pack as in figure 1. B, after calculus remains in dilated superior calix (arrow). Stent been passed into bladder and protrudes through nephrotomy. tapes (T) suspend kidney. Wrinkled appearance of kidney ischemia (artery is still clamped) and hypothermia. Commercial plastic wrapped film. C, final film after renal repair and re-establishment of blood flow. Silicone stent 0.095 in outside diameter (approximately 2.6 mm.) now extends into lower calix (arrow).
Fie. 1. Graphic
5 by 7 inches and head-sealed in heavy being aligned beam from plastic draped collimated X·ray tube. Kidney, suspended on cotton tapes, will be held against cassette and centered in x-ray beam.
outline of the renal segment with a small number of sutures (fig. 3). Conventional roentgenograms of the are then made and used to plan the nephrotomy incisions 4 to 6). The localization of caliceal calculi may be further assisted intrasurgical pyelography (fig. 7). This process is accom plished by temporary occlusion of the ureter with an elastic vessel loop, and the direct aspiration and injection of the ren3.J pelvis with contrast material through a very small needle. Such exposures, of course, must be made prior to the tomy but are quite capable of defining anterior and calices and, most importantly, they provide the anatomical re· lationship of the various calices and, thus, assist the surgeon in localization of the infundibulopelvic ostia, where these may
154
BOYCE
be partially or completely occluded. 17 In a number of instances this technique has demonstrated hydrocalices that were not visualized previously by conventional pyelography, owing to the sclerosis of the infundibular orifice and the absence of calculus or excreted contrast material within the calix. RADIOLOGIC TECHNIQUE
The technique applicable to intraoperative radiography of the kidney is commonly referred to as "organ radiography".
Fm. 3. Radiopaque thread from surgical gauze sponges outlines posterior renal arterial segment. Vessel loops surround main and posterior renal arteries. A, rotation toward surgeon. B, rotation away from surgeon.
The technique generally provides maximum shades of gray or softness of the display. The energy beam must be as free of divergent rays as possible, in light terminology the rays should be polarized. The flat surface of the film must be as nearly as possible at precise right angles to the central beam. Sterilizable or sterilely draped extension tubes 4 to 10 inches in diameter were once placed directly around the surgically exposed kidney to achieve these results. Modern portable xray equipment achieves the same effect through collimators but there is still a distinct advantage in bringing the source as close to the kidney as possible. Sterile commercially available plastic drapes permit the tube to be placed directly into the operative field and the distance from the film is generally 5 to
Fm. 5. A, intraoperative film of kidney made in position illustrated in figure 3, B. B, intraoperative exposure from convex surface to hilus of kidney as in figure 3, A. Two commercial film packs are overlapped about the renal pedicle.
Fm. 4. A, plain film and B, tomogram of kidney in figure 3.
LOCALIZATION OF INTRARENAL CALCULI DURING SURGERY
155
of the operating table. This is accomplished lateral rotation (rolling) of the table and by variations of the position in order to bring the kidney into the central beam without interference of any kind. It is most important achieve the necessary definition of renal anatomy and calculi prior to any incision within the kidney. The plain renal x-ray. This film made immediately after the kidney is properly mobilized will provide a wealth of information. Small calculi not previously visualized even phy can be clearly depicted. Many large branched calculi appear to be solid bodies in conventional x-rays will demon strate innumerable planes of cleavage (non-union) between the various segments of the stone. Since the calculus is in fragments the approach to the stone may be quite different than if it is indeed a solid body. Furthermore, the surgeon is forewarned that having removed a cast of an infundibulurn, FIG. 6. Stone fragments reveal innumerable planes of non-union, completely invisible in figure 4 but visible in figure 5.
10 inches in practice. Light indicators with associated crosshairs permit the precise centering of the central beam on the kidney and adjustment of the shutters to a field size not larger than the kidney itself. The surgeon must assume responsibility for the proper placement of the source and the relative placement of the kidney and film. When flexible films are used a sterile metal or plastic plate may be utilized to support the kidney on cotton tapes and to maintain the film in a flat position closely applied to the kidney and at the proper angle to the beam during the exposure (fig. 8). Anesthesia must control breathing and other motion during exposure. The exposure time is in the range of0.02 seconds and at energy levels of approximately 60 kilovolt peaks, which result in relatively low scatter of radiation to either patient or surgical personnel. Nevertheless, lead screens should be rolled into the room and lead aprons should be provided for anesthetists and for those individuals unable to leave the room during the exposure (fig. 9). Needless to say, the radiologic technician must be thoroughly familiar with organ radiography and with the various exposures required the different types of film and plates in use. SURGICAL TECHNIQUE
The quality of intraoperative organ radiography ultimately resides with the surgeon. Preoperative planning is most important in developing a knowledge of whether the stone is highly mobile, in the localization of the stone to a particular calix and in determining the number of stones present in the kidney. To this end, most patients require preoperative tomography without contrast material plus a perfect set of pyeloureterograms made in the conventional anteroposterior position and with maximal rotation in 2 directions. Such films are best made by coned projections of each kidney and their usefulness may be enhanced by the magnification technique when this is available. In the presence of stones retrograde pyeloureterograms are generally more reliable and superior to excretory urography (IVP), not only because of the greater contrast but also the ability to vary the contrast (dilution of media or air pyelography) and the greater likelihood of filling a partially obstructed calix through control of intrarenal pressure and gravity flow. The infundibula of such calices cannot be reliably defined by IVP. Whatever the information attainable from in vivo radiography of renal calculi it will be less definitive than a properly made intraoperative x-ray of the kidney. The surgeon should, therefore, plan the approach for maximum mobilization of the FIG. 7. Intraoperative pyelography. A, convex-hilar kidney so that appropriate films can be made. The kidney without contrast medium. B, same as part A after direct ,uJ'""''vu having first been mobilized may be placed accurately in rela- pelvis. C, exposure along short axis of kidney. Reprinted with pertion to the x-ray beam and the film by temporary positioning mission.17
156
BOYCE
there are many potential fragments completely unattached to this cast that may be left within the cusp of the affected calix (fig. 10). Intraoperative pyelography. Many kidneys containing large branched calculi of the infectious type will also have innumerable minute calcifications located within the collecting tubules of the papillae (fig. 10). Pyelography, as described in the aformentioned radiologic technique, will demonstrate clearly the presence of these stones within the parenchyma rather than calices of the kidney. Furthermore, such pyelograms
Fm. 8. Flexible kidney film and kidney supported by plastic "board" in proper alignment of central beam with film.
provide a much needed orientation of each calix to its neighbors and to the renal pelvis. The most difficult calculi and fragments to locate in this type of stone are those trapped within a calix, the infundibulum of which has been partially or completely sclerosed. A proper pyelogram will direct the surgeon to the precise point at which such infundibula enter the pelvis even if no contrast material fills the strictured infundibulum (figs. 11 and 12). The radiopaque thread technique for outlining the arterial segments of the kidneys as previously described is carried out with or without pyelography and prior to any incision into the kidney. The surgeon should never succumb to the temptation of having seen a small fragment of stone on a film and having subsequently removed a fragment of stone from the kidney, thereby assuming that he has recovered all of the calculus. It should be a cardinal rule to make a final roentgenogram that has, indeed, demonstrated the complete removal of all fragments of stones from the calices before repair of the kidney is undertaken.
Fm. 10. Intraoperative film of kidney prior to nephrotomy. Note separation of large calculi, which was not apparent on preoperative films. Calcifications within papillary ducts and probably collecting tubules are visible (IT). Note non-union and many separate calculi within inferior calices (JC). Removal oflarge calculus without opening calix will probably leave 2 large stones in lower-most calix.
Fm. 9. Portable x-ray unit with table draped with sterile plastic. Note portable lead screen on surgeon's side of table and lead aprons for anesthetists and technician.
LOCALIZATION OF INTRA.RENAL CALCULI DURING SURGERY
Fm. 11. A, conventional pyeloureterogram of kidney containing multiple calculi and strictures of proximal ureter. B, plain film of kidneys, ureters and bladder. SUMMARY
There is an ever-increasing wealth of technical knowledge and u1 1JrnLcaJ,c available for accurate localization of even the most minute and poorly mineralized concretions within the surgically exposed kidney. A practical and generally satisfactory technique is illustrated in figures 8 and 9. The cassette is Kodak Kidney Surgery Pack containing 2 sheets of film. The x-ray unit contains a collimated source with illuminated cross-hairs for of the shutters and centering of the beam. The entire arm of the unit is draped with sterile commercially available drapes. The exposure is 6 milliamperes per second seconds) with a 60 kilovolt peak at a distance of 5 inches from the film. The film is developed in an ordinary rapid processor and is ready for viewing within 1 to 5 minutes. This equipment and technique are available in practically all surgical suites and meet the requirements for the vast majorof undergoing an operation for renal calculi.
FIG. 12. A, intraoperative film (overlapping films were cut and spliced for this illustration). Note several small calculi not seen in figure 11. B, intraoperative pyelogram. Large dilated posterior caJix (X) containing calculus and strictured infundibulum was not visualized on any preoperative IVP or retrograde pyelogram. This cavity probably represents site of prior nephrostomy used for through-and-· through irrigation. Radiopaque thread outlines posterirnr renal segment. Silicone ureteral stent was positioned preoperatively,
6. 7.
8. 9. 10. 11. 12.
REFERENCES
1. Singh M., Marshall, V. and Blandy, J.: The residual :renal stone, Brit. J. Urol., 47: 125, 1975. 2. W. H., Pool, C. S., Meschan, I. and King, J. S., Jr.: matrix of urinary calculi. Microradiographic comparison of crystalline structure with microscopic and histochemical studies. Acta Radio!., 50: 543, 1958. 3. Braasch, W. F. and Carmen, R. D.: Renal fluoroscopy at the operating table. J.A.M.A., 73: 1751, 1919. 4, Sutherland, C. G.: Renal roentgenoscopy and roentgenography at the operating table. J. Urol., 33: 1, 1935. 5. Baskin, A. M., Harvard, B. M. and Janzen, A. H.: Sterile 1
157
13. 14. 15. 16. 17.
fluoroscopy: preliminary report of a new technique for localiw,tion of renal calculi. J. Urol., 78: 821, 1957. Harrison, L. H. and Boyce, W. H.: Image intensification fluornscopy. J. Urol., 116: 348, 1976. Burke, D. E.: Isotope radiographs for localization ofrenal calcuii during surgery: a new truly portable radiographic unit using 8 radioisotope (thulium 170) as an energy source. J. Urnl., 508, 1956. Beer, E.: Roentgenological control of exposed tions for nephrolithiasis, with the use of special cassette. J. Urol., 25: 159, 1931. Quinby, W. C.: Note on the localization ofrenal calculi by the aid ofx-ray films made during operation. J. Urol., 13: 59, 1925. Schlegel, J. U., Diggdon, P. and Cuellar, J.: The use ofultrn,·· sound for localizing renal calculi. J. Ural., 86: 367, 1961. Andaloro, V. A., Jr., Schor, M. and Marangola, J. P.: ative localization of a renal calculus using Ural., 116: 92, 1976. Cook J. H., III and Lytton, B.: Intraoperative localization of renal calculi during nephrolithotomy by ultrasound scanning. J. Urol., 117: 543, 1977. Spence, H. 0.: Personal communication, 1977. Linke, C. A., Rogoff, S. M., Lind, B. and Fridd, C. W.: Intra. operative roentgenograms of kidney. Technique. Urology, 28, 1974. Sutherland, C. G.: Roentgenoscopy and roentgenography of kidney at the operating table. Surg. Clin. N. Amer., 19: 1041, 1939. Hanley, H. G.: Flexible renal grid-sling for localising stones during lithotomy. Lancet, 1: 661, 1967. Boyce, W. H.: Radiology in the diagnosis and surgery of rena} calculi. Radio!. Clin. N. Amer., 3: 89, 1965.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
THE LOCALIZATION OF INTRARENAL CALCULI DURING SURGERY WILLIAM H. BOYCE From the Section of Urology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina
ABSTRACT
This is a summary review of past and present technology for accurate anatomical localization of calculi within the surgically exposed kidney. The methodology is applicable to reconstructive renal surgery for pathological processes other than calculi. Like the beauty in nature some very important individuals are so close to us that they are taken for granted. As Editor of The Journal of Urology, founder of Urological Survey, teacher, leader, advisor and friend, Dr. Hugh J. Jewett has been such an individual to all urologists. His brilliant intellect has appeared in innumerable facets: incisive, analytical investigator; pioneering, meticulous surgeon; superb teacher; precise, demanding editor; wise and sympathetic counselor; humorist and raconteur. For all your many contributions to Urology and to urologists, we salute you, "Huey". A voluminous literature on the subject of this review dates from the second decade of this century to the present time. Clinical use and application appear to have lagged behind the technical advances in this field to a remarkable degree. 1 In simplistic terms the roentgenogram depicts relative differences in density along the path of the beam. Since all crystalline structures are of distinctly different density than that of living tissue it appears theoretically possible to identify within the exposed kidney any crystalline mass large enough to be visible to the unaided eye. The proper modification of the x-ray beam and the choice of film with appropriate qualities of resolution are the only requirements for success. The feasibility of achieving this was demonstrated clearly with equipment available in 1958 as used in the study of microscopic structure of native human calculi. 2 The purpose of this review is to summarize the historical developments as they relate to current technical capabilities and, thereby, to establish the fact that in this area of endeavor the theoretical is indeed capable of practical application. EQUIPMENT AND ENERGY SOURCES FOR IONIZING RADIATION
Fluoroscopy was one of the earliest techniques employed for this purpose. 3 Its utilization continued in pace with technological improvement in the equipment and, particularly, in display screens. 4 Intraoperative use of this technique with a considerable degree of success was reported in 1957. 5 The obvious advantage offluoroscopy is in the rapid localization of the stone as it relates to a metal pointer or other point of reference. Disadvantages of fluoroscopy relate to radiation hazards, the difficulty of manipulating C-arms in surgical fields, a lack of adequate resolution of small calculi and the expense of maintaining such equipment within the limited space of conventional surgical rooms. However, the technique continues to be of considerable importance in the cystoscopic extraction and surgical removal of ureteral calculi. i; The atomic age provided access to radioisotopes as sources for ionizing radiation. These offered the promise of highly mobile sterilizable units capable of introduction directly into the operative field. The surgical use of thulium 170 for this purpose was described by Burke. 7 Failure to use gamma rays probably relates to difficulty in adjustment of the field strength from the energy source, the expense of maintaining the equipment and, possibly, failure of commercial development. In any event, the technique is not of current practical importance.
Conventional portable x-ray tubes have been used in the operating rooms for purposes of localization of stones since the second decade of the century. 8• " Current models of the portable x-ray tube are available universally. They provide a maximum opportunity to modify the characteristics of the beam through appropriate adjustments of kilovolts peak, timing in milliseconds, collimation and adjustment of the size of the field. In all probability this type unit will remain the energy source of choice for some time to come. Ultrasonography, first utilized for intrarenal localization of calculi by Schlegel and associates in 1961 10 and currently undergoing continuing investigation, 11 • 12 may ultimately supplant ionizing radiation for this purpose. DISPLAY UNITS, FILM AND FILM HOLDERS
Flexible sterile holders. Conventional radiosensitive film in flexible sterile holders was the first recording graphic display unit used during surgery and continues to be the most widely used technique. Quinby wrapped his film in light-proof paper and, at the time of the operation, dropped the unsterile packets into previously sterilized rubber bags. 9 This basic technique is used today in our institution, when exceptionally large kidneys or exceptional problems of resolution require film packs that are not available commercially. The film of appropriate characteristics, such as high resolution industrial film or glass plate, is cut to the appropriate size and sealed in a single wrap of light-proof black paper, which is secured by cellulose or paper tape. The wrapped film is then placed in a bag of heavy plastic of appropriate size and sealed with heat. At the time of the operation the entire bag is sterilized by soaking in formaldehyde-hexachlorophene isopropanol solution. Any solution appropriate for cold sterilization is acceptable ifit is compatible with plastics. The plastic bags, so sealed, resist leakage even in boiling water. Bags and sealer are available at a modest cost in most hardware and department stores under the general category of food savers. The major disadvantage of flexible film is the distortion of the image and resultant surreptitious dislocation of the stone with respect to the renal outline. This problem has been solved by Spence who has advocated spot films of the kidney since 1962. "Bite-wing" dental film is wrapped in sterile paper and dental radiologic techniques are used to pinpoint the position of the stone. 13 Commercially prepared film in sealed plastic bags appropriate for cold sterilization are marked currently as Kodak Kidney Surgery Film. 14• * These films are of relatively small size, contain a notch to accommodate the renal pedicle and, recently, have included 2 sheets of film of different sensitivity so that relatively soft and hard radiograms.are obtained from a single exposure. Static electrical exposure may be a problem in the manipulation of any flexible film pack. Solid cassette holder. Beer introduced very thin aluminum cassettes made in the shape of the kidney and containing * Kodak X-Omat KS film, Eastman Kodak Company, Rochester, New York. 152
LOCALIZATION OF INTJRARENAL CALCULI DURING SURGERY
double intensifying screens much in the nature of available cassettes. 8 These were 3¼ by 4¼ inches in size dropped into a sterile rubber glove at the time These cassettes were in widespread use at this in the fifth decade and provided excellent definition of intrarenal calculi. Kodak the series of "M Plates" of type B panchroand high resolving power for use in photomiin the fifth and sixth decades. were 3¼ inches and were loaded easily 5 graphic plate-type cassettes, which were available 7-inch sizes for larger displays (fig. 1). The rigid the kidney to be applied against a srn.ooth, and reduced the distortion occasioned a relaflexible against a highly .. -"·"-··- film. These cassettes require sealing in leak-proof plastic and cold sterilization. Such high resolution plates provide superb definition of the smallest intrarenal collections of crystal and, indeed, surpass the resolving power of the normal human eye. Future developments in electronic imaging may obviate the use of film in surgery. For the present, however, the commercapable of providing clear definicially available film is tion of the and woof of ordinary cotton surgical tapes the kidney and of medicinal grade silicone inches outside diameter (fig. 2). localization of calculi. Available display techinformation in only 2 dimensions, To achieve a functional aspect of depth many types of markers have been The most widely used technique, introduced by in 1939, consisted of placing straight needles at as near the stone as possible and then obtaining exposures. 1' introduced a wire that ,nrv,vtn.-J the kidney in front of the x-ray film and provided recognizable nc.a,n·r,Q of grids whereby the stone could be respect to the margins of the kidney. 16 localized With the development of hypothermia and the demonstrable of approaching the renal pelvis and calices placed between the arterial segments of the it became advantageous to establish the relationship of the calculus-containing calix to these planes of approach. The arterial segments are defined first by intravenous administration of methylene while various arteries supplying the segments of the kidney are clamped selectively. The arterial segments, having been so defined, are then outlined by removing appropriate lengths of the radiopaque thread from surgical gauze sponges. The thread is held in place along the FIG. 2. Intraoperative radiograms. A, before small concretions appear to be within parenchyma kidney. Cassette pack as in figure 1. B, after calculus remains in dilated superior calix (arrow). Stent been passed into bladder and protrudes through nephrotomy. tapes (T) suspend kidney. Wrinkled appearance of kidney ischemia (artery is still clamped) and hypothermia. Commercial plastic wrapped film. C, final film after renal repair and re-establishment of blood flow. Silicone stent 0.095 in outside diameter (approximately 2.6 mm.) now extends into lower calix (arrow).
Fie. 1. Graphic
5 by 7 inches and head-sealed in heavy being aligned beam from plastic draped collimated X·ray tube. Kidney, suspended on cotton tapes, will be held against cassette and centered in x-ray beam.
outline of the renal segment with a small number of sutures (fig. 3). Conventional roentgenograms of the are then made and used to plan the nephrotomy incisions 4 to 6). The localization of caliceal calculi may be further assisted intrasurgical pyelography (fig. 7). This process is accom plished by temporary occlusion of the ureter with an elastic vessel loop, and the direct aspiration and injection of the ren3.J pelvis with contrast material through a very small needle. Such exposures, of course, must be made prior to the tomy but are quite capable of defining anterior and calices and, most importantly, they provide the anatomical re· lationship of the various calices and, thus, assist the surgeon in localization of the infundibulopelvic ostia, where these may
154
BOYCE
be partially or completely occluded. 17 In a number of instances this technique has demonstrated hydrocalices that were not visualized previously by conventional pyelography, owing to the sclerosis of the infundibular orifice and the absence of calculus or excreted contrast material within the calix. RADIOLOGIC TECHNIQUE
The technique applicable to intraoperative radiography of the kidney is commonly referred to as "organ radiography".
Fm. 3. Radiopaque thread from surgical gauze sponges outlines posterior renal arterial segment. Vessel loops surround main and posterior renal arteries. A, rotation toward surgeon. B, rotation away from surgeon.
The technique generally provides maximum shades of gray or softness of the display. The energy beam must be as free of divergent rays as possible, in light terminology the rays should be polarized. The flat surface of the film must be as nearly as possible at precise right angles to the central beam. Sterilizable or sterilely draped extension tubes 4 to 10 inches in diameter were once placed directly around the surgically exposed kidney to achieve these results. Modern portable xray equipment achieves the same effect through collimators but there is still a distinct advantage in bringing the source as close to the kidney as possible. Sterile commercially available plastic drapes permit the tube to be placed directly into the operative field and the distance from the film is generally 5 to
Fm. 5. A, intraoperative film of kidney made in position illustrated in figure 3, B. B, intraoperative exposure from convex surface to hilus of kidney as in figure 3, A. Two commercial film packs are overlapped about the renal pedicle.
Fm. 4. A, plain film and B, tomogram of kidney in figure 3.
LOCALIZATION OF INTRARENAL CALCULI DURING SURGERY
155
of the operating table. This is accomplished lateral rotation (rolling) of the table and by variations of the position in order to bring the kidney into the central beam without interference of any kind. It is most important achieve the necessary definition of renal anatomy and calculi prior to any incision within the kidney. The plain renal x-ray. This film made immediately after the kidney is properly mobilized will provide a wealth of information. Small calculi not previously visualized even phy can be clearly depicted. Many large branched calculi appear to be solid bodies in conventional x-rays will demon strate innumerable planes of cleavage (non-union) between the various segments of the stone. Since the calculus is in fragments the approach to the stone may be quite different than if it is indeed a solid body. Furthermore, the surgeon is forewarned that having removed a cast of an infundibulurn, FIG. 6. Stone fragments reveal innumerable planes of non-union, completely invisible in figure 4 but visible in figure 5.
10 inches in practice. Light indicators with associated crosshairs permit the precise centering of the central beam on the kidney and adjustment of the shutters to a field size not larger than the kidney itself. The surgeon must assume responsibility for the proper placement of the source and the relative placement of the kidney and film. When flexible films are used a sterile metal or plastic plate may be utilized to support the kidney on cotton tapes and to maintain the film in a flat position closely applied to the kidney and at the proper angle to the beam during the exposure (fig. 8). Anesthesia must control breathing and other motion during exposure. The exposure time is in the range of0.02 seconds and at energy levels of approximately 60 kilovolt peaks, which result in relatively low scatter of radiation to either patient or surgical personnel. Nevertheless, lead screens should be rolled into the room and lead aprons should be provided for anesthetists and for those individuals unable to leave the room during the exposure (fig. 9). Needless to say, the radiologic technician must be thoroughly familiar with organ radiography and with the various exposures required the different types of film and plates in use. SURGICAL TECHNIQUE
The quality of intraoperative organ radiography ultimately resides with the surgeon. Preoperative planning is most important in developing a knowledge of whether the stone is highly mobile, in the localization of the stone to a particular calix and in determining the number of stones present in the kidney. To this end, most patients require preoperative tomography without contrast material plus a perfect set of pyeloureterograms made in the conventional anteroposterior position and with maximal rotation in 2 directions. Such films are best made by coned projections of each kidney and their usefulness may be enhanced by the magnification technique when this is available. In the presence of stones retrograde pyeloureterograms are generally more reliable and superior to excretory urography (IVP), not only because of the greater contrast but also the ability to vary the contrast (dilution of media or air pyelography) and the greater likelihood of filling a partially obstructed calix through control of intrarenal pressure and gravity flow. The infundibula of such calices cannot be reliably defined by IVP. Whatever the information attainable from in vivo radiography of renal calculi it will be less definitive than a properly made intraoperative x-ray of the kidney. The surgeon should, therefore, plan the approach for maximum mobilization of the FIG. 7. Intraoperative pyelography. A, convex-hilar kidney so that appropriate films can be made. The kidney without contrast medium. B, same as part A after direct ,uJ'""''vu having first been mobilized may be placed accurately in rela- pelvis. C, exposure along short axis of kidney. Reprinted with pertion to the x-ray beam and the film by temporary positioning mission.17
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there are many potential fragments completely unattached to this cast that may be left within the cusp of the affected calix (fig. 10). Intraoperative pyelography. Many kidneys containing large branched calculi of the infectious type will also have innumerable minute calcifications located within the collecting tubules of the papillae (fig. 10). Pyelography, as described in the aformentioned radiologic technique, will demonstrate clearly the presence of these stones within the parenchyma rather than calices of the kidney. Furthermore, such pyelograms
Fm. 8. Flexible kidney film and kidney supported by plastic "board" in proper alignment of central beam with film.
provide a much needed orientation of each calix to its neighbors and to the renal pelvis. The most difficult calculi and fragments to locate in this type of stone are those trapped within a calix, the infundibulum of which has been partially or completely sclerosed. A proper pyelogram will direct the surgeon to the precise point at which such infundibula enter the pelvis even if no contrast material fills the strictured infundibulum (figs. 11 and 12). The radiopaque thread technique for outlining the arterial segments of the kidneys as previously described is carried out with or without pyelography and prior to any incision into the kidney. The surgeon should never succumb to the temptation of having seen a small fragment of stone on a film and having subsequently removed a fragment of stone from the kidney, thereby assuming that he has recovered all of the calculus. It should be a cardinal rule to make a final roentgenogram that has, indeed, demonstrated the complete removal of all fragments of stones from the calices before repair of the kidney is undertaken.
Fm. 10. Intraoperative film of kidney prior to nephrotomy. Note separation of large calculi, which was not apparent on preoperative films. Calcifications within papillary ducts and probably collecting tubules are visible (IT). Note non-union and many separate calculi within inferior calices (JC). Removal oflarge calculus without opening calix will probably leave 2 large stones in lower-most calix.
Fm. 9. Portable x-ray unit with table draped with sterile plastic. Note portable lead screen on surgeon's side of table and lead aprons for anesthetists and technician.
LOCALIZATION OF INTRA.RENAL CALCULI DURING SURGERY
Fm. 11. A, conventional pyeloureterogram of kidney containing multiple calculi and strictures of proximal ureter. B, plain film of kidneys, ureters and bladder. SUMMARY
There is an ever-increasing wealth of technical knowledge and u1 1JrnLcaJ,c available for accurate localization of even the most minute and poorly mineralized concretions within the surgically exposed kidney. A practical and generally satisfactory technique is illustrated in figures 8 and 9. The cassette is Kodak Kidney Surgery Pack containing 2 sheets of film. The x-ray unit contains a collimated source with illuminated cross-hairs for of the shutters and centering of the beam. The entire arm of the unit is draped with sterile commercially available drapes. The exposure is 6 milliamperes per second seconds) with a 60 kilovolt peak at a distance of 5 inches from the film. The film is developed in an ordinary rapid processor and is ready for viewing within 1 to 5 minutes. This equipment and technique are available in practically all surgical suites and meet the requirements for the vast majorof undergoing an operation for renal calculi.
FIG. 12. A, intraoperative film (overlapping films were cut and spliced for this illustration). Note several small calculi not seen in figure 11. B, intraoperative pyelogram. Large dilated posterior caJix (X) containing calculus and strictured infundibulum was not visualized on any preoperative IVP or retrograde pyelogram. This cavity probably represents site of prior nephrostomy used for through-and-· through irrigation. Radiopaque thread outlines posterirnr renal segment. Silicone ureteral stent was positioned preoperatively,
6. 7.
8. 9. 10. 11. 12.
REFERENCES
1. Singh M., Marshall, V. and Blandy, J.: The residual :renal stone, Brit. J. Urol., 47: 125, 1975. 2. W. H., Pool, C. S., Meschan, I. and King, J. S., Jr.: matrix of urinary calculi. Microradiographic comparison of crystalline structure with microscopic and histochemical studies. Acta Radio!., 50: 543, 1958. 3. Braasch, W. F. and Carmen, R. D.: Renal fluoroscopy at the operating table. J.A.M.A., 73: 1751, 1919. 4, Sutherland, C. G.: Renal roentgenoscopy and roentgenography at the operating table. J. Urol., 33: 1, 1935. 5. Baskin, A. M., Harvard, B. M. and Janzen, A. H.: Sterile 1
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13. 14. 15. 16. 17.
fluoroscopy: preliminary report of a new technique for localiw,tion of renal calculi. J. Urol., 78: 821, 1957. Harrison, L. H. and Boyce, W. H.: Image intensification fluornscopy. J. Urol., 116: 348, 1976. Burke, D. E.: Isotope radiographs for localization ofrenal calcuii during surgery: a new truly portable radiographic unit using 8 radioisotope (thulium 170) as an energy source. J. Urnl., 508, 1956. Beer, E.: Roentgenological control of exposed tions for nephrolithiasis, with the use of special cassette. J. Urol., 25: 159, 1931. Quinby, W. C.: Note on the localization ofrenal calculi by the aid ofx-ray films made during operation. J. Urol., 13: 59, 1925. Schlegel, J. U., Diggdon, P. and Cuellar, J.: The use ofultrn,·· sound for localizing renal calculi. J. Ural., 86: 367, 1961. Andaloro, V. A., Jr., Schor, M. and Marangola, J. P.: ative localization of a renal calculus using Ural., 116: 92, 1976. Cook J. H., III and Lytton, B.: Intraoperative localization of renal calculi during nephrolithotomy by ultrasound scanning. J. Urol., 117: 543, 1977. Spence, H. 0.: Personal communication, 1977. Linke, C. A., Rogoff, S. M., Lind, B. and Fridd, C. W.: Intra. operative roentgenograms of kidney. Technique. Urology, 28, 1974. Sutherland, C. G.: Roentgenoscopy and roentgenography of kidney at the operating table. Surg. Clin. N. Amer., 19: 1041, 1939. Hanley, H. G.: Flexible renal grid-sling for localising stones during lithotomy. Lancet, 1: 661, 1967. Boyce, W. H.: Radiology in the diagnosis and surgery of rena} calculi. Radio!. Clin. N. Amer., 3: 89, 1965.
