CHAPTER XXIV
Wounds of the Kidney (427 Casualties)
Walter L. Byers, M.D.
Wounds of the kidney occurred in 427 (13.5 percent) of the 3,154 abdominal injuries treated by teams of the 2d Auxiliary Surgical Group during 1944 and 1945 (table 84). The official history of the American participation in World War I1 lists the frequency of renal injuries in that war as 6.3 percent, which is slightly higher than the 5.4 percent reported by Young in his Practice of Urology2 (table 85).
TABLE 84.-Essential data in 427 wounds of kidney
Type of wound | Cases |
| Deaths | Case fatality rate | |
| In 427 renal injuries | ||||
|
|
| Percent |
|
|
Univisceral | 56 | 1.8 | 13.1 | 9 | 16.1 |
Multivisceral | 371 | 11.8 | 86.9 | 146 | 39.4 |
Thoracoabdominal | 147 | 4.7 | 34.4 | 67 | 45.6 |
Abdominal | 280 | 8.9 | 65.6 | 88 | 31.4 |
| 427 | 13.5 | 100.0 | 155 | 36.3 |
In all but 56 cases, the renal wounds were multivisceral (table 84). The colon (211 cases), the liver (168 cases), the small intestine (105 cases), and the stomach (67 cases) were most frequently involved. It is a matter of technical interest that 37 of the 105 wounds of the small intestine occurred in the duodenum in association with wounds of the right kidney, and that the pancreas was wounded 20 times in association with wounds of one kidney or the other. The ureter was damaged along with the kidney in 5 cases and the bladder in 8 cases. Approximately a third of all wounds of the kidney were thoraco?abdominal (table 84).
1The Medical Department of the United States Army in the World War. Washington: U. S. Government Printing Office, 1927, vol. XI, pt. 1.
2Young, Hugh H.; and Davis, David M.: Young's Practice of Urology. Philadelphia: W. B. Saunders Co., 1926.
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| Total series | Renal injuries | Frequency |
|
|
| Percent |
World War I, American (Young)1 | 2,385 | 129 | 5.4 |
World War I, British2 | 965 | 73 | 7.6 |
Spanish Civil War3 | 238 | 19 | 8.0 |
2d Auxiliary Surgical Group | 3,154 | 427 | 13.5 |
1Young, Hugh H.; and Davis, David M.: Young's Practice of Urology. Philadelphia: W. B. Saunders Co., 1926.
2The British figures are from War Surgery of the Abdomen, by Cuthbert Wallace (London: J. & A. Churchill, 1918).
3The Spanish Civil War figures were reported by Douglas W. Jolly in Field Surgery in Total War (New York: Paul B. Hoeber, Inc., 1941).
ANATOMIC CONSIDERATIONS
The anatomy of the kidney is such that the organ possesses both advantages and disadvantages in respect to vulnerability to battle-incurred injuries. It is well protected within the body by adipose tissue, muscle, bone, and the visceral structures of the abdomen and chest. It is also conceivable that perirenal adipose tissue may cushion the blow from a missile; it was noted several times in this series that in injuries which had resulted in extensive fragmentation of the liver or the spleen, only perforation or segmental destruction of the kidney had occurred. On the other hand, the kidney bears such a close anatomic relationship to adjacent and nearby structures that any injury in this area was likely to result in renal involvement, while any injury of the kidney was likely to be accompanied by damage to other viscera from the same missile.
Examination of the autopsy records in this group of cases revealed no instances of renal agenesis or of fused or horseshoe kidney. Cystoscopy and urography were not feasible in forward areas, but the possibility that nephrectomy might be performed for a renal injury on one side upon a patient with agenesis of the opposite kidney was constantly borne in mind, and in every case an effort was made by roentgenologic examination to distinguish the renal shadow on the uninjured side before operation was undertaken
NATURE OF THE INJURY
In the 399 cases in which these data were recorded, 284 injuries (71.2 percent) were caused by fragmentation missiles, including all types of grenades, artillery shells, land mines, boobytraps, and bombs. Small-arms fire accounted for the remaining cases.
For convenience of discussion, wounds of the kidney may be classified under two headings, those involving the renal hilum and those involving the renal parenchyma.
Injuries of the hilum.-There were only 16 wounds of the hilar structures
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in this series, with 9 deaths, all of them after nephrectomy. In 15 cases, the injury was either a laceration or a complete severance of the renal vessels, in 2 instances complicated by damage to the inferior vena cava. In one of these cases, the inferior vena cava was completely transected and the patient died in the course of operation. In the other, repair of the laceration proved impossible, and the vein had to be ligated; the patient was evacuated in good condition on the ninth day, with apparently normal urinary volume. In another case, a laceration of the renal vein was overlooked, and death occurred from continued hemorrhage. In the only hilar injury in which the renal vessels were not damaged, a laceration of the pelvis was repaired with a single interrupted suture, and recovery was uneventful.
The very small number of wounds of the renal vessels observed in forward hospitals suggests that casualties with such injuries, particularly if other major abdominal blood vessels were also injured, did not usually survive long enough to be submitted to surgery.
Injuries of the parenchyma.-Injuries of the renal parenchyma ranged from neatly drilled holes to complete disintegration of the tissues. The size of the missile and its velocity were directly responsible for the degree of destruction, but otherwise there was no apparent relationship between the type of missile and the character of the wound. A hematoma of variable size was practically always present in the perirenal area, and the wound was usually covered with an irregular clot which was rather firmly adherent to its edges. Active bleeding from the renal wound was not a constant finding, even in the event of destruction of large sections of one pole or the other, but attempts at operation to dislodge the clot from the wound usually resulted in renewed bleeding from the wound surface. Cortical hemorrhage had frequently caused separation of the tunica fibrosa, sometimes of considerable extent, with varying degrees of disturbance of the anatomic relationship of the capsule to the cortex. During mobilization of the parts, the surgeon often unwittingly perforated the distended capsule, so that a subcapsular dissection was actually performed.
CLINICALCONSIDERATIONS
The chief symptoms and signs in wounds of the kidney were tenderness, guarding of the muscles of the flank, and hematuria. A retroperitoneal hematoma could occasionally be palpated through the flank and abdomen, but muscle guarding frequently made deep palpation difficult or impossible. In the multivisceral injuries which comprised the bulk of these renal injuries (table 84), the predominance of intraperitoneal symptoms and signs arising from wounds of other viscera was likely to overshadow the symptoms and signs of renal injury. Hemoperitoneum and peritoneal contamination, because of the resulting muscle guarding, added to the difficulties of satisfactory abdominal palpation. When pain was present, it was commonly referred to the abdomen. There was apparently no case in this series in which it was referred in the classic manner along the course of the ureter to the groin or the scrotum.
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A wound of the renal parenchyma alone did not always elicit a particularly severe general reaction, and shock might be either mild or absent. In some cases, however, chiefly of injury to the renal vessels and of other viscera, shock was so deep that physical findings obtained by palpation were totally unreliable until resuscitation therapy had begun to be effective.
DIAGNOSIS
The two most important diagnostic evidences of renal damage were the location of the wound and the presence of hematuria. The physical findings, as already noted, were relatively slight insofar as localization to the kidney was concerned, and were also likely to be confused by the reaction of other viscera to injuries.
Close inspection of the wound was often useful in determining what struc?tures were involved. It was always helpful, particularly in penetrating wounds, if the patient could describe his position at the time of wounding or knew the direction from which the missile had come. In univisceral wounds, the causative missile was likely to be traveling at low velocity; the fragment was therefore likely to be found in the kidney or adjacent to it when the wound was explored. At other times, the angle of penetration was such that only the kidney was wounded. In thoracoabdominal wounds, the usual direction of penetration was posteriorly and posterolaterally from the chest into the abdomen. The costophrenic angle was frequently involved. The size of the wounds of entrance and exit was never an index of the extent of damage to the kidney.
It was sometimes possible, by careful inspection, to detect some disparity in the appearance of the flanks, but no difference was likely to be observed unless there had been considerable destruction of tissue or a hematoma of considerable size was present. Bleeding from wounds of the flank and loin did not necessarily point to hilar damage. The renal parenchyma can bleed vigorously, and intraperitoneal blood can also escape from a wound in the flank.
Although a wound into the pelvis provided a direct communication from the kidney to the exterior surface of the body, attempts to identify urine in the wound or about the kidney were seldom successful. Catheterization was practically always necessary to recover urine specimens. The absence of blood could not be assumed until the bladder was completely emptied. It was not unusual for the first portion of the catheterized specimen to be clear and the last portion to be grossly discolored with blood, especially if there had been a long timelag since wounding.
Roentgenologic examination in forward units was limited to flat films and fluoroscopy; stereoscopy, retrograde pyelography, intravenous urography, and similar diagnostic refinements were not practical under field conditions. More over, retrograde pyelography was regarded as undesirable because cystoscopy is sometimes attended with some degree of shock. If shock from this cause had been superimposed on shock from wounding, a seriously wounded casualty might conceivably have been placed in still further jeopardy.
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TREATMENT
Specific treatment was deliberately withheld in 8 of the 427 renal injuries, because it was not regarded as necessary. It was not instituted in 3 other cases, because the renal wound was overlooked. The remaining cases were chiefly managed by nephrectomy or by drainage only.
Surgical approach.-An abdominal transperitoneal approach was employed in 259 (61.7 percent) of the 420 injuries in which the type of incision was listed because it was necessary in these cases to expose abdominal viscera along with the kidney. The risk of retroperitoneal contamination inherent in this approach was fully realized, but the objection was regarded as less valid than under other circumstances, because of the probability that contamination was already present as the result of the original wound. A combined abdominal?flank incision might have been more desirable, but it was not employed, chiefly because of the added time it would have required.
Thoracotomy was employed in 64 (43.5 percent) of the 147 wounds of the kidney in which the thorax was wounded also. This transdiaphragmatic approach to the abdomen and retroperitoneal area proved convenient, and when it was employed on proper indications the results were good. In 40 cases, separate incisions were made into the thorax and into the abdomen; in 39, the approach was transabdominal; and in 3, the injury was approached through the flank. In the remaining case, the renal injury was overlooked.
The flank or loin incision was found preferable for wounds limited to the upper quadrants of the abdomen. This approach provided excellent exposure and had the added advantage that the incision could be extended anteromedially for laparotomy and for necessary operations on the abdominal viscera. It practically always healed by primary intention. This was not, however, a desirable incision when the large bowel was also injured, since it interfered with proper exteriorization of the colon.
Procedures.-Nephrectomy was performed in 120 of the 427 renal injuries (28.1 percent). It was employed in 16 cases because of damage to the renal artery and vein and was used in the other cases because of extensive destruction of the renal parenchyma. A less radical procedure was always chosen when it was practical, but damage to the renal vessels, extensive destruction of the renal parenchyma, and widespread fracture of the kidney with destruction of the blood supply to the segments frequently left the surgeon with no other choice.
Drainage was the only procedure in 285 cases (66.7 percent of the total number). It was also carried out in association with other procedures in 134 other cases (all but 8 of the renal injuries treated by other surgical measures). It was conveniently accomplished by soft rubber material of the Penrose type, with or without a wick. If the original wound was not suitably located, drainage was instituted through a separate stab wound. Otherwise, debrided missile tracks in the flank or loin were utilized for this purpose. Complete debridement was the rule before drainage was instituted.
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Resection and suture, which were used in only seven cases, were not popular in the 2d Auxiliary Surgical Group, probably for the reason brought to light by autopsy in the single fatal case in which the method was used. The notation read: "During the 3-day interval between surgery and death, the sutures had become buried in the swollen renal parenchyma, while the areas included were dark, and engorged with blood on section."
Packing was employed three times. This was another method not highly regarded, and control of hemorrhage by other measures was preferred, for obvious reasons. Because firm pressure is necessary to accomplish hemostasis, the gauze had to be packed firmly from the renal fascia to the skin level, and the immediate consequence was inhibition of drainage in an area already potentially, if not actually, infected. Furthermore, fresh bleeding was always a possibility when the pack was removed.
Capsulotomy was employed in one case in the series. Nephrostomy was not employed at all.
Suture material.-Ordinary types of suture material proved satisfactory for all procedures on the kidney except segmental resections and repair of fractures of the parenchyma. The inclusion of ribbon suture material in the tables of equipment for forward hospitals would have been an incentive to even further conservatism and might have made unnecessary a few of the nephrectomies which were performed.
POSTOPERATIVE MANAGEMENT
Drains were left in place as long as there was significant soiling of the dressings, which was usually 7 to 10 days. Dressings over a large wound in the flank through which drainage of the renal fossa had been established had to be changed several times daily. The repeated removal of adhesive tape caused skin irritation, and the entire task proved too time consuming for busy nurses. Another type of dressing was therefore devised. The wound was covered with a few sterile gauze sponges reenforced by one or two abdominal pads, all held in place by a large bath towel which encircled the abdomen and was secured anteriorly with safety pins. With this method, changes of dressings could be quickly and easily accomplished, and excoriation of the skin by adhesive tape was entirely avoided.
An extremely important phase of the postoperative management of renal wounds was an adequate fluid intake, ranging from 2,000 to 3,000 cc. daily by mouth or parenterally. Otherwise, the postoperative routine did not differ from the usual routine for abdominal wounds.
POSTOPERATIVE COMPLICATIONS
Sepsis seldom occurred in wounds of the kidney, except in association with perforation of the retroperitoneal portion of the colon. It was guarded against by thorough debridement of the wound, with excision of dead tissue, free blood, bits of clothing and metallic foreign bodies, and by adequate drain-
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age. Secondary hemorrhage does not seem to have occurred in any case in the series.
Because urinary fistulas seldom occur in renal injuries except after wound?ing of the parenchyma with involvement of the renal pelvis, they were not common in this series. Pocketing of the urine as the result of inadequate drainage also was uncommon. When it did occur, it was accompanied by a febrile reaction, and the patient's condition did not improve until adequate drainage was established. Urine was often noted on the dressings, but as a rule, urinary drainage ceased spontaneously after a few days. Nephrostomy, as already noted, was not performed in any case in the series.
FACTORS OF MORTALITY
As would be expected, the case fatality rate in wounds of the kidney depended upon whether they were univisceral or multivisceral (table 84). The multiplicity factor proved as important from the standpoint of prognosis as it proved in all other regional injuries (table 10, fig. 22).
Seventeen of the fifty-six univisceral injuries were treated by nephrectomy, with four deaths. One occurred from shock 20 minutes after the operation was concluded. The second was the result of anaphylactic shock. It occurred on the seventh postoperative day, immediately after the intravenous infusion of 100 cc. of Alsever's solution. The third patient died of anuria. The fourth died of ascending myelitis from an associated injury of the spinal cord.
There were 49 deaths (47.6 percent) in the 103 nephrectomies performed in the multivisceral injuries. This case fatality rate is to be compared with the 44.2-percent rate for nephrectomy in the whole series (53 of 120 operations).
The time of death could be determined from the records in 149 of the 155 fatal cases. It occurred within the first 72 hours after operation in 120 cases (80.5 percent). The great majority of these patients had sustained wounds which were essentially lethal, and their deaths were attributable to shock.
