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Bladder and prostate cancer are the most common urological malignancies that require radical surgical intervention. Enhanced recovery programmes have demonstrated the benefit of early mobilization, of which a key element is the need for adequate postoperative analgesia [1, 2]. When performed using an open surgical approach, pelvic cancer resections usually involve a lower midline abdominal incision, and thoracic epidural analgesia (TEA) remains popular with evidence of superior postoperative pain control compared with systemic analgesia . Epidural catheters, however, are not without problems, both in terms of their initial placement and their postoperative care [4-6]. Technical failure of insertion is reported in 6–7% of cases [7, 8] and, in 25–30% of patients, TEA does not offer adequate analgesia [9-11]. There is conflicting evidence regarding the effects of TEA on bowel recovery after colonic surgery. Concern exists regarding the effect of TEA on blood flow and anastomotic healing, and there remains concern that excess fluid and electrolyte disturbance as a result of the management of TEA-induced hypotension may prolong ileus and affect anastomotic healing [4, 12-17]. Furthermore, controversy remains regarding their impact on cancer recurrence and patient survival [18-20]. TEA is known to be resource heavy and a recent cost-effectiveness analysis demonstrated a higher use of medical and nursing time in the placement and ongoing supervision of TEA when compared with patient-controlled analgesia (PCA) or a continuous wound infiltration device .
Rectus sheath catheters (RSCs) have emerged as an alternative to TEA for the management of postoperative pain in selected patient groups undergoing major abdominal surgery [22, 23]. The aim of the technique is to block the ventral rami of the 7th to 12th intercostal nerves that supply the rectus abdomini muscles and overlying skin . A rectus sheath block, whereby a compartmental block of T7–T12 is achieved by injecting local anaesthetic into the potential space that exists between the rectus muscles and the posterior rectus sheath, has been previously described in paediatric anaesthesia [25, 26]. The addition of an indwelling catheter within the space allows the block to be ‘topped up’ at regular intervals and has been variously described in point-of-technique reports and small case series [23, 27]. The routine use of RSCs in major urological surgery was previously reported in a retrospective series of 20 patients undergoing open radical cystectomy (ORC), 10 of whom had RSCs and 10 of whom had epidural analgesia. In the RSC group, this demonstrated a high success rate of insertion, with good levels of pain control and low rates of failure or complications .
In the current series, we have analysed data on a large cohort of 200 patients undergoing open radical pelvic urological surgery.
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The present paper reports our experience using an alternative analgesic technique to TEA for patients undergoing major open pelvic urological surgery. From a patient safety perspective, RSCs can avoid the rare but potentially catastrophic complications associated with infection in the epidural space . The benefit may have increasing relevance when taking into consideration the increasing use of antiplatelet medications, such as clopidogrel or the more recent direct thrombin inhibitors such as dabigatran. A haematoma of the rectus sheath is of much less significance than that of the epidural space and, as a consequence, allows the use of RSCs when epidural catheters are otherwise contra-indicated owing to concomitant anticoagulation. In our experience, RSCs appear to meet the requirements of enhanced recovery principles in providing effective pain control whilst allowing early mobilization. Following the introduction of an enhanced recovery programme which incorporated RSCs, we noted a marked reduction in the LOS for patients undergoing both ORC and RRP in the present series. We accept the reduced LOS cannot be solely attributed to RSC usage, but, compared with TEA, RSC facilitates early mobilization of patients and would seem more beneficial to an enhanced recovery programme.
The rate of successful placement of RSCs was high, as judged by ultrasound visualization of catheter placement. Their reliability in the postoperative period was also found to be high with low numbers requiring early removal (Table 2). This compares favourably with published failure rates of TEA . Surgical placement of RSCs, either blindly or with dissection, is an alternative technique ; however, in a recent audit of practice within our hospital, the surgically placed RSCs were more likely to have problems such as blockage or early removal. It was also noted that patients required a greater amount of rescue analgesia.
Our experience during the ‘spread and adoption’ phase of this technique suggests that the learning curve for the insertion of RSCs is steep, particularly in those individuals previously experienced in ultrasonography-guided regional anaesthesia. The identification of the relevant radiological landmarks is straightforward and there are clear endpoints associated with successful insertion.
In combination with a multimodal analgesia regimen, the use of RSCs was associated with low patient-reported pain scores in both groups. In the initial postoperative 24 h (Fig. 2), ORC was associated with a higher level of discomfort when compared with RRP and this is most probably attributable to the more significant visceral pain component associated with intra-abdominal dissection.
As anticipated, all patients had additional analgesia requirements over and above RSC usage suggesting that a multimodality regimen is required. Regular paracetamol was used as per protocol and patients had varying needs for tramadol and NSAID administration. The requirement for additional opiate analgesia was more complex, and varied according to the nature of the procedure, the individual patient, clinician choice and evolving experience with RSC. Postoperative opiates were delivered by three main routes; namely, as an i.v. bolus, in the form of PCA, or as oral morphine.
Within the noted limitations of the paper, some pragmatic observations on opiate administration can be made. Approximately 40–50% of patients undergoing ORC appear to need regular, additional opiate administration, usually in the form of PCA. Conversely, > 50% of patients undergoing ORC did not require PCA. This figure hasn't altered greatly during the 3-year implementation and adoption phase of RSC use within our institution. It is likely to represent the varying degrees of visceral pain in a proportion of patients having ORC. Interestingly, the visceral pain component appears to be relatively short-lived, and opiate requirements fell sharply after 24 h, suggesting that RSCs are an effective way to maintain adequate analgesia.
By contrast to ORC, the use of PCA in patients undergoing RRP has diminished over the 3 years of the series and routine use of PCA in this patient group has almost ceased. In the early adoption period, PCA was administered routinely on the assumption that visceral pain would be problematic. The extraperitoneal approach used in RRP suggests that the majority of postoperative pain in this group is in fact wound-related and hence ideally suited to the RSC technique. For patients in whom no PCA was used (Fig. 5), there was a low opiate requirement and this was given mainly as oral morphine.
Very few additional reviews of the patient were required for hypotension. When this is considered in conjunction with Table 2, patients who underwent ORC or RRP with RSCs required a low number of out of hours review by the medical staff. This supports the noted perception by ward staff that the RSC led to fewer problems compared with other methods of analgesia and it is possible they will represent less of a burden than TEA, but this would need to be assessed in a prospective randomized setting.
The low rate of wound infections in this series (3%) is likely to be multifactorial and compares favourably with recent series of open cystectomy procedures [30-32]. It has been postulated that, as RSCs deliver local anaesthetic to the anterior abdominal wall, this may play a role in reducing wound infection rates. It has been demonstrated in the laboratory that local anaesthetics, including bupivacaine, at concentrations typically found in the clinical setting possess inherent antimicrobial properties against a wide spectrum of human pathogens . More recently, the use of local anaesthesia was associated with a lower incidence of surgical site infections in day-case general and vascular surgery .
The ileus rate for patients undergoing ORC in this series was ∼20%. The criteria used to define ileus in the current series deliberately erred on the side of overdiagnosis and hence the rate compares favourably with historical series of ORC where ileus rates of 18–22% were reported, suggesting equivalence with epidural analgesia at the very least [30-32]. In the subset of patients studied, approximately one third were documented to have nausea within the initial 24 h.
In terms of costs, the current methodology was not designed to capture the full economic costing associated with the new technique when compared with TEA so only limited comments can be made. For the majority of units performing major surgery, portable ultrasound machines are likely to be in routine use and therefore not a directly incurred cost of RSC adoption. The cost of disposable items used in the block is marginally greater than TEA as two catheters are required in addition to two fixation Epifix dressings. Procedural time appears equivalent once the procedure is routinely embedded in clinical practice. Local anaesthetic costs are low as the local anaesthetic is drawn up on the ward rather than relying on the more expensive pre-filled syringes used for TEA. In terms of the nursing and clinical manpower required to maintain the block, the results of our series suggest that non-scheduled review of RSCs is infrequent and it would clearly be of interest to compare this aspect with an equivalent TEA-based cohort. Only a randomized controlled trial would be able to answer whether RSC offers an advantage in terms of reducing LOS and the incumbent costs compared with TEA.
Our findings support the continued investigation of RSCs as an effective alternative to TEA for patients undergoing major open urological pelvic surgery, but the study has some limitations. This was a retrospective review of a technique, therefore, only data that were available within the 200 cases could be analysed. In addition, the present series, by its nature, does not allow any direct comparison with other analgesia techniques. Naturally, comparison is drawn with TEA, but only anecdotal evidence for such a comparison is available at present. There is a need for adequately powered randomized controlled trials to further investigate the role of RSCs in major pelvic surgery. A pilot of such a trial is currently underway (ISRCTN77620476). Such a trial would also aid in the determination of cost of using RSCs in practice. As discussed above, whilst a ‘procedural’ cost can be attributed to the disposables used, determining the true cost of an alternative technique such as this is complex and beyond the capability of the current case series. The methodology would necessitate a prospectively designed trial intended to capture total costs, including not only the procedural time and hardware costs but also those of nursing and medical time as well as the projected cost of unintended consequences with regard to complication rates. The data available in this current series do not allow this aspect to be explored fully.
In conclusion, although it is recognized that an increasing number of pelvic urological procedures are being performed with minimally invasive surgery, RSCs offer a reliable, safe and effective method by which analgesia can be delivered to patients recovering from major open pelvic surgery. They can be a key component of a multimodal analgesia regime and have been associated with a low number of complications. They are a low-maintenance device for patients and ward staff and early mobilization is possible. Further work is needed to determine their exact role in patient recovery as well as the optimum adjunctive forms of analgesia within different patient groups. Future planned work will allow direct comparison with TEA in terms of pain control, complication rates and compatibility with enhanced recovery principles.