In recent years, with the increasing incidence of global terrorist attacks, trap-bombs, improvised explosive devices (IEDs), and rock-et-propelled grenades (RPGs) related injuries have been a part of trauma centers of tertiary and military hospitals. Among these injuries, secondary blast injuries caused by traveling penetrating shell fragments are common source of explosion and combat related injuries (8, 9). But renal traumas due to these travelling shell fragments consist of a rarity. In some circumstances these shell fragments retain in the body and occasionally cause complications primarily depending on the anatomical location and the reaction with the surrounding tissue. In general, the shrapnel is thought to be left inert in the tissue, and can be managed conservatively. It can be removed in acute and subacute stage if there is need for debridement secondary to infection or later stage in cases of complications, such as local tissue complications (eg, abscess) or systemic toxicity (eg, plumbism) (5). Among all published English literature, there is only few case reports about renal shell fragments caused injuries (10, 11), and most of them are focusing on long term complications. When we searched PubMed we did not notice any paper focusing the management of renal shell fragments caused injuries secondary to explosives with retaining renal shell fragments.
Management of renal trauma leads excessive studies in the English literature. However, all penetrating injuries historically required exploration, improved imaging and interventional techniques, increased the role of non-operative management in some selected renal penetrating injuries (12, 13). In hemodynamically stable patients without any presence of intraabdominal injuries, non-operative management of penetrating renal injuries are now thought to be feasible (12, 14). With this increasing popularity of non-operative management of renal injuries over the last decades, in combination with the fact that the shell fragments are left inert in the tissue had encouraged us to manage these injuries non-operatively. So we conducted this retrospective study and reviewed our experience of such injuries. Our study’s greatest value is being the largest and unique patient cohort of renal shell fragment wounds secondary to blast injuries with long term follow-up morbidity rates.
In our series seven patients had AAST grade 1–3 and one patient had AAST grade 4 renal injury. None had grade v injury. None required more than 4 units of blood transfusion except one with grade 4 injury. All had systolic blood pressure more than 90 mmHg, and pulse rate less than 120 bpm at the hospital admission. In our patient cohort we were able to manage all patients without major surgical intervention, including nephrectomy, nephron sparing surgery and even renal embolization. When interpreting our results, we must keep in mind that our patient cohort was hemodynamically stable, and there was no sign of abdominal organ injury and peritonitis. In all patients preoperative imaging with contrast enhanced CT with delayed images revealed no pelvis or ureteral injury or major urine extravasation. But we must also keep in mind that our patient cohort is somehow different from all other studies with including only renal injuries caused by shell fragments. It is notable that none of our patients required adjuvant surgery, embolization or urinary diversion. We attributed the low adjuvant treatment necessity in our series to the low rate of AAST grade 4 renal injuries. In our patient cohort the entire population was eight patients and there was only one patient with AAST grade 4 renal trauma. Anyone can speculate that the increasing number of entire patient cohort in combination with increasing AAST renal injury grade may increase non-operative management failure and increase the necessity of adjuvant surgeries and procedures. But when we consider the rarity of the selected group among all renal injuries caused by explosives, our findings are very important for the literature.
Renal injuries caused by shell fragments are heavily contaminated with foreign bodies such as soil and clothing, with subsequent increased risk of infection (15). Despite increased risk of infection, empiric antibiotic use is still disputed due to increased risk of resistant infections. There is also discrepancy for the appropriate prophylactic antibiotic spectrum: a narrow or a broad-spectrum one (16). Historically gram-positive organisms like S. pyogenes and S. aureus are the major group of bacteria that are responsible for many infection types following penetrating traumas (17). In the literature there is no study focusing solely the antibiotic prophylaxis in either renal shrapnel injuries or renal gunshot injuries. In our series, we introduced prophylactic antibiotics because of the fact that all patients had retaining contaminated shell fragments that may lead infection. Tetanus prophylaxis was also done according to immunization status. No patient had neither renal abscess nor pyelonephritis during hospitalization or during follow-up period.
Although the fact that shell fragments are left inert in the tissue and there is no need for surgical removal in the late stage, they may be associated with several complications and must be removed in some circumstances (5). Late re-activation of retained metallic fragments has been reported in various organs (11) also including kidney. They can cause several pathological changes in adjacent organs or the organ itself. In a case Naeem et al reported renal colic and percutaneous removal of renal artillery shell fragment 17 years after primary exploding artillery shell injury (11). In another study, Jvaheri et al reported renal Failure in a Solitary Functioning Left Kidney secondary to a migrating 9 mm bullet ten years after injury (29). Retained shell fragments may also cause plumbism or exposure to depleted uranium due to release of chemical elements (5, 11, 18). After mean 38.7 month of follow-up, we reached all patients in order to question the complication rates. We made a phone call and questioned if they have any sign of plumbism or need surgical intervention due to any complications of retaining shrapnel fragments. During 38.7 months of follow-up after primary trauma none had any systemic or local complications secondary to retained shell fragments. In the literature the complications in some cases are seen after 17 years of trauma (11), and one can speculate that with increasing follow-up there can be complications. Its true, nevertheless, the results of our study gives a major contribution to the English literature with being the largest series showing no complication of renal retaining foreign bodies with in a mean 38.7 months of follow-up.
Everyone must keep in mind that all our encouraging results of non-operative management for renal injuries caused by shell fragments are taken from the database of a tertiary university hospital that harbor experienced 24-hour in-house trauma surgeons, interventional radiologists, and medical staff. So non-operative management options may not be applicable for all medical centers. Again we must keep in our minds that careful observation and close monitoring are the essential parts of conservative managements in all renal injuries. If there is a lack of an experienced team, exploration options or referring patient to a more experienced center might be a safer alternative for both surgeon and patient. The major limitation of our study is its retrospective manner.