Pain After Surgical Correction of Congenital Chest Wall Deformities



Fig. 9.1
CT scan of a patient with severe PE (Haller Index of 7) as well as significant sternal tilt





9.1.2 Surgical Technique


The standard approach to repair of PE is the thoracoscopic-assisted Nuss procedure. Championed by Dr. Nuss and the team from Virginia, this procedure involves the transthoracic insertion of a metal bar with affixation to the lateral chest wall [2, 3]. Briefly, after surgical marking and prophylactic antibiotic administration, oblique skin incisions are made in the anterior axillary line at the point of deepest sternal depression (typically T5–6). A second small incision is then made in the right chest, and a port is inserted into the thoracic space followed by gentle insufflation and insertion of a thoracoscope. A tunneler is then use to dissect from lateral to medial, entering the chest just medial to the ridge above the point of maximal depression. Once intrathoracic, the tunneler is then gradually advanced under direct vision above the pericardium until the opposite chest is reached. Once brought through, heavy suture material is affixed to both the tunneler and the chosen bar – after it has been bent to shape. The tunneler is then slowly withdrawn, bringing the suture and Nuss bar with it. Once the Nuss bar is in position, it is then flipped, immediately correcting the deformity. Care is then taken to ensure the bar is adequately secured to the lateral chest – a stabilizer is typically used on one side. Pneumothorax is then ceased, air is allowed to egress from the chest, and wounds are closed in layers.

An alternative technique for repair of PE involves an open approach to remove abnormal costal cartilages, performance of a wedge osteotomy to elevate the sternum, and insertion of a retrosternal strut to maintain the reconfigured sternum in place. This modified Ravitch repair continues to have applications in patients with stiff chest walls or those that have had prior attempts at a chest wall reconstruction. It remains the procedure of choice for some surgeons [4].


9.1.3 Analgesic Considerations


Comparative studies have suggested that the Nuss procedure is associated with increased postoperative pain compared with the modified Ravitch procedure [57]. Nonetheless, no differences have been noted in patient satisfaction or overall outcomes between the two groups [8]. In both cases, the length of hospitalization is typically dictated by the ability to adequately achieve effective analgesia. A recent large multi-institutional observational study has demonstrated that pain typically crescendos at 8/10 (median) during hospitalization and improves to 3/10 before discharge with a variety of different analgesic techniques [9]. Importantly, this cohort of patients demonstrates improved body image and perceived ability for physical activity after surgery [10].

Three main options exist for early postoperative pain relief: thoracic epidural (TE), patient-controlled analgesia (PCA), and a continuous paravertebral nerve block (PVNB). Elective repair of pectus excavatum is an ideal indication for placement of a TE catheter – a recent global survey of 108 pediatric institutions revealed that 91 % of respondents used thoracic epidurals as the primary mode of analgesia [11]. While these allow for sparing systemic narcotics, concerns remain about rare but devastating complications like paraplegia [12]. Older prospective trials comparing epidural catheters with intravenous PCA have demonstrated equivalency in pain relief and length of stay [13, 14]. This has resulted in several centers publishing their preference for PCA, especially given the significant number of patients with failed epidurals [15, 16]. A recent randomized trial of 110 patients receiving either epidural or PCA revealed a 22 % failure rate for epidural and an increase in resource utilization for epidural patients with only modest differences in very early pain scores compared to PCA patients [17]. A subsequent meta-analysis of available literature confirmed a small improvement in pain scores through to 48 h after surgery, without significant differences in secondary outcomes [18].

Thus, it is currently unclear whether epidural or PCA is the optimal analgesic strategy given the apparent small benefit but small increased risk associated with epidural. An attractive alternative is a continuous paravertebral nerve block – potentially marrying the improved analgesia of an epidural without the increased risk [19]. Two recent retrospective comparisons of PVNB to standard epidural have suggested equivalent efficacy without the need for urinary catheterization [20, 21]. Clearly, further prospective evaluations of PVNB for pectus excavatum repair are required prior to widespread adoption.

Chronic pain after Nuss procedure remains a rare but devastating consequence after an elective operation. Twenty-two percent of anesthesiologists responding to a survey on the subject disclose referring at least one patient per year for chronic pain treatment [11]. The true rate of chronic pain after Nuss procedure is difficult to ascertain as is it not commonly reported in surgical reports. Every effort must be taken to adequately treat early postoperative pain with multimodal therapy in order to avoid the transition to long-term pain. Should this occur, dedicated treatment in a pain clinic should be considered mandatory.



9.2 Pectus Carinatum



9.2.1 Background


This deformity is generally believed to be less common than pectus excavatum, with centers reporting PC to be half as common as PE [22]. The deformity is manifest as overgrowth of the cartilaginous costo-sternal junctions. The deformity can be symmetric or asymmetric and occasionally involves protrusion of the manubrium as well. It is associated with other musculoskeletal conditions only very rarely and an extensive workup is typically unnecessary. Unlike PE, the treatment of choice for PC has rapidly become compression bracing. While reports of corsets and other binders have been in existence for many years, the modern era of bracing began with the description of dynamic compression bracing from Dr. Martinez-Ferro in Argentina [23]. This device gradually reduces the anteroposterior chest dimension while allowing room for lateral expansion. It (or variations of it) has been widely adopted and has made the operative repair of PC much less frequent [24]. Nonetheless, a subset of patients either desire immediate or delayed correction while others fail compression bracing and subsequently undergo surgery.


9.2.2 Surgical Techniques


Pectus carinatum is traditionally treated by the Ravitch procedure [25]. This involves excision of multiple offending costal cartilages followed by one or several osteotomies to achieve an appropriate chest contour. Typically, a large dissection is required and a closed-suction drain is left in the operative field and only removed once the output decreases. More recently, a “reverse Nuss” has been described. Also known as the Abramson based on its originator, a Nuss bar is passed in front of the deformation and secured under tension to the lateral thoracic wall in order to retract the protrusion [26]. This technique has shown promise; however further studies are required before it can be considered generalizable.


9.2.3 Analgesic Considerations


The Ravitch procedure is generally considered to be less painful than the Nuss procedure [57]. As a consequence, less effort has been placed in investigating analgesic strategies in the perioperative period. Although the reporting is incomplete, Fonkalsrud et al. report a series of Ravitch procedures without epidural placement and minimal analgesics required at the time of discharge to hospital [27]. For patients undergoing the “reverse Nuss,” the most appropriate analogous operation is the Nuss and not the Ravitch. As such, the debate about thoracic epidural versus PCA versus the emerging option of PVNB is highly relevant. Further investigations will be required to evaluate this patient subset in further detail.

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Sep 22, 2016 | Posted by in ANESTHESIA | Comments Off on Pain After Surgical Correction of Congenital Chest Wall Deformities

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