The incidence of complications related to linear staplers is difficult to ascertain, as they may not be routinely reported and mechanisms to document them are not standardized. Additionally, minor complications that are easily salvaged are less likely to be reported, and thus the scope of complications from these devices is likely underestimated. Often the exact etiology of a complication related to a linear stapler is difficult to pinpoint and theoretically could be due to a flaw in the device itself, user error, or patient factors. Adding to the complexity in understanding these problems is the fact that stapling devices are manufactured by different companies and their technologies continue to evolve and are released to surgeons without clinical studies to document their relative efficacy, equivalence, or superiority. Among surgical stapler users, urologic robotic surgeons are unique in their common use of these devices to control large blood vessels where a device malfunction could lead to immediate disaster. This is in contrast to malfunction during open surgery or during operations not centered around the control of large blood vessels where salvage of a complication may be easier and the complication presentation may not be as acute or severe.

In terms of reported complications, stapler misfires associated with incomplete staple formation or the inability to safely release the tissue from the device jaws appear to be most commonly mentioned. The US Food and Drug Administration (FDA) maintains a Manufacturer and User Facility Device Experience (MAUDE) database that collects hundreds of thousands of reports related to deaths, injuries, and malfunctions associated with medical devices [1]. Several groups have studied malfunctions and injuries attributed to linear staplers.

Brown et al. [2] looked at all surgical stapler-related adverse events in the MAUDE database irrespective of surgery type or approach. In a 10-year period, they identified 112 deaths that were related to surgical staplers. The majority of the cases were in gastrointestinal surgery , and approximately half of the cases resulted from staples not forming or other device failure/malfunction at the time of firing. They also analyzed FDA recalls from 1983 to 2003 and showed that 22 staplers were recalled, several of which were due to manufacturing issues relating to incomplete staple formation. Deng et al. [3] reviewed an institutional database of 460 laparoscopic urologic cases and found the rate of stapler-related complications to be about 1%. All of these complications occurred during radical nephrectomy or nephroureterectomy. Among these cases, 60% required open conversion, and 40% resulted in significant blood loss and transfusion.

Although stapler malfunctions causing injury are a rare event, the majority of laparoscopic surgeons feel that they have experienced at least one malfunction, and one third of surgeons have experienced three or more [4]. It is important to note that not all stapler-related malfunctions are primary device failures and can be the result of improper use and technique. This may be particularly true in cases of multiple failures during the same operation or recurrent failures for specific operators. The following section will address appropriate technique to prevent device failure.

Due to the proximity of the renal vessels to the aorta and inferior vena cava (IVC), RALRN represents the highest-risk operation for linear stapling within robotic urologic surgery. Stapler malfunctions can quickly lead to uncontrolled bleeding putting patients at risk for open conversion, blood transfusion, or death if not quickly controlled.

Hsi et al. [5] analyzed the MAUDE database from 1992 to 2006 and identified 111 stapler-related malfunctions during radical nephrectomy. The most common complications were incomplete staple line formation (47%) and difficulty releasing from tissue (30%). Chan et al. [6] analyzed the stapler use in laparoscopic nephrectomy from 1993 to 1999 at two institutions and assessed malfunctions primary to the device (e.g., missing staples, ligation failure) compared to secondary preventable causes (e.g., deployment over surgical clip, poor positioning). This group found a malfunction rate of 1.7% out of 565 cases and showed that 70% of the malfunctions were preventable with proper technique. Proper stapling techniques include ensuring appropriate position of the staple jaws completely across the vessel to be ligated. In addition, it is important that no additional tissue be interposed between the device that could cause incomplete staple formation. Appropriate loading and reloading of the device is required for effective use, and any signs that the device may be loaded incorrectly should prompt investigation and testing prior to its use on tissue. It is important to note that surgical stapler placement across clips is a common cause of device failure in radical nephrectomy. When placing clips for control of non-hilar vessels, care should be taken to avoid placing clips near the hilum where the stapler will be deployed. In patients with heavily calcified vessels, the operator should avoid areas of heavy vascular calcification while stapling which can lead to unpredictable results. Adherence to these basic techniques can significantly decrease the rate of stapler-related complications. In a current review of the MAUDE database for the last 10 years, there were two deaths and six serious injuries reported to the FDA-related to stapler-related complications after laparoscopic nephrectomy. Both deaths and 4/6 injuries were related to stapler misfire where the full staple line did not fire or did not seal a portion of the artery or vein. The additional two injuries were related to the stapler not releasing from tissue after firing. In these reports there was no way to assess for user error compared to primary device failure [1]. In general, stapling of the renal hilum is safe with a low complication rate, but when complications do occur, they are usually significant requiring quick action. If a stapling misfire is suspected, the jaws should not be released from the vessel and more proximal control should be obtained before removing the device. If this is unable to be performed safely robotically, then open conversion may be necessary to gain vascular control.

En bloc hilar stapling is advocated by some surgeons and institutions as a way to simplify the operation and decrease blood loss. Several studies have reported this technique to be safe and lead to decreased blood loss and operative time without an increase in immediate postoperative complications. Resorlu et al. [7] analyzed 60 patients who underwent laparoscopic radical nephrectomy and compared those who had separate ligation vs en bloc ligation with linear staplers. This group showed that both groups had similar blood loss and length of stay but that the en bloc stapling group had approximately 20 min shorter operative course. They further showed that there were no stapler-related complications in either of the groups and concluded that en bloc stapling is a safe technique. However, it is also important to note that by taking both the renal artery and vein with one staple line, there is a theoretical risk of increased arteriovenous (AV) fistula formation. A prospective randomized trial studied the presence of AV fistula after en bloc stapling vs separate ligation in 60 patients and showed that with 12 months follow-up, no patients had developed an AV fistula in either group [8]. These data suggest that en bloc stapling is a safe technique with comparable complications to individual ligation. However, longer-term follow-up may be needed to definitively rule out an increased risk in AV fistula.