Nuss technique in pectus excavatum: a mono-institutional experience

Effect of medial stabilizer chest position on pectus bar dislocation

PURPOSE

The current standard method for pectus excavatum (PE) repair is the Nuss procedure. One major postoperative complication is the displacement of the implanted metal bar, which is used to remodel the chest wall. Blocking the possible ways that the bar can be displaced with the use of stabilizers and peri/intracostal sutures has reduced the incidence of bar displacement. Despite the modifications, bar dislocation is often reported. We adopted the medial position stabilizer placement method and imposed no postoperative restrictions. In this study, we analyzed the bar dislocation rate with this modification and concurrent postoperative full activity.

METHODS

Nuss procedure modification where stabilizers are placed bilaterally in the medial location was done on patients irrespective of age and Haller index greater than 3.25. A single bar was used for all patients. Cryoanalgesia was performed on every patient. No postoperative restrictions were imposed on the patients. Full immediate activities, including sports, were allowed.

RESULTS

114 patients (103 male, 11 female) were analyzed from 2016 to 2023. The median age was 15 years old. There was zero incidence of bar displacement. The combined incidence of other postoperative complications was 4%: 2 wound infections and 2 hematoma formations, both needing incision and drainage.

CONCLUSION

Bilateral medial stabilizer placement resulted in no incidence of bar dislocation. Return to immediate full activities after the Nuss procedure did not appear to increase the incidence of bar displacement if stabilizers were placed medially.

Evaluation of cross-bar and parallel-bar techniques in MIRPE surgery in different countries: a multicenter study

Parallel- and cross-bar techniques are surgical methods used in the pectus excavatum. While the parallel bar is used in many centers, the cross bar is a new technique. The aim of the study is to evaluate the data of centers using cross bar and parallel bar. The aim of this multicenter study is to retrospectively evaluate the data of centers have been using both cross-bar and parallel-bar techniques. 213 parallel bars and 205 cross bars were used. Parallel-bar advantages: the mean patient satisfaction score was 9.40 ± 0.95. Cross-bar advantages: the rate of patients with symmetric deformity was 75.6%, recurrence 0.5%. The mean patient satisfaction score was 9.40 ± 0.95 in operations performed with the parallel-bar technique and 9.13 ± 1.11 in operations performed with the cross-bar technique (p < 0.05). Recurrence was observed in 3.3% of patients undergoing surgery using the parallel-bar technique and 0.5% of patients undergoing surgery using the cross-bar technique (p < 0.04). The cross-bar technique is more advantageous in terms of the recurrence, while second, the parallel-bar technique is associated with greater patient satisfaction. Comparison of data from different countries reveals the differences between patients who have been treated with minimally invasive repair of pectus excavatum and the outcomes of surgery.

Novel techniques and future developments in minimally invasive pectus repair

After the paradigm shift in the treatment of excavated deformities caused by the introduction of the Nuss technique in 1998, several innovative technical modifications and new treatment modalities have radically changed the surgical approach of pectus excavatum in the last couple of years. These new trends attain different topics. On one hand, the use of three-dimensional (3D) printing and implant customization surge as a possibility for a wider audience as 3D printers become available with lower costs. They provide the surgeon with new elements that enable precise planning, simulation, and customized prostheses amidst a tendency to abandon standardization and incorporate personalized medicine. Another topic comprises mandatory sternal elevation, in the continuous search for safety first always. Complete thoracic remodeling as a goal of repair instead of addressing only focal depressions, leaving the upper chest or focal protrusions unresolved. Finally, although the current surgical approach has evolved significantly, many groups still use lateral stabilizers or direct implant fixation with sutures or wires to the ribs. These systems continue to prove unreliable in preventing implant displacement. Fortunately, the bridge technique, described in this review, has come to address this sometimes fatal issue with encouraging results. We provide an updated overview of the latest developments regarding these concepts, related to the current state-of-the-art of the treatment of pectus excavatum.

Minimally invasive repair of pectus excavatum in adults: a review article of presentation, workup, and surgical treatment

Pectus excavatum (Pex) is one of the most common congenital deformities of the chest wall, with pectus constituting 90% of all chest wall deformities and excavatum being reported in almost 1:400 to 1:1,000 live births with predominant occurrence in males up to five times more than in females. Depending on the severity, presentation varies from mild cosmetic complaints to life limiting cardiopulmonary symptoms. Patients may develop symptoms as they age, and these symptoms may worsen over the years. A technique for minimally invasive repair for pectus excavatum (MIRPE) was introduced with the concept of temporarily implanting metal bars to correct the deformity. This has rapidly become the standard of care for the pediatric and adolescent patients. The use of MIRPE in adults, however, has been slower to adopt and more controversial. This is largely due to the increased calcification and rigidity of the chest wall in adults which can make the repair more complex and lead to a higher risk of complications. We present a literature review of the presentation, workup, and surgical treatment of adult patients with Pex undergoing MIRPE. Adult patients can, with advanced preoperative evaluations and technique modifications, undergo a highly successful repair resulting in symptom resolution and satisfying results.

The management of pectus excavatum in pediatric patients: a narrative review

Background and Objective

Pectus excavatum is the most common congenital chest wall anomaly, the hallmark of which is the caved-in appearance of the anterior chest. A growing body of literature exists surrounding methods of surgical correction, though considerable variability in management remains. The primary objectives of this review are to outline the current practices surrounding the care of pediatric patients with pectus excavatum and present emerging trends in the field that continue to impact the care of these patients.

Methods

Published material in English was identified utilizing the PubMed database using multiple combinations of the keywords: pectus excavatum, pediatric, management, complications, minimally invasive repair of pectus excavatum, MIRPE, surgery, repair, and vacuum bell. Articles from 2000-2022 were emphasized, though older literature was included when historically relevant.

Key Content and Findings

This review highlights contemporary management principles of pectus excavatum in the pediatric population, comprising preoperative evaluation, surgical and non-surgical treatment, postoperative considerations including pain control, and monitoring strategies.

Conclusions

In addition to providing an overview of pectus excavatum management, this review highlights areas that remain controversial including the physiologic effects of the deformity and the optimal surgical approach, which invite future research efforts. This review also features updated content on non-invasive monitoring and treatment approaches such as three-dimensional (3D) scanning and vacuum bell therapy, which may alter the treatment landscape for pectus excavatum in order to reduce radiation exposure and invasive procedures when able.

Current Development of Minimally Invasive Repair of Pectus Excavatum (MIRPE)

For decades, open surgical repair was the only available method to treat congenital and acquired chest wall deformities (CWDs). In 1998, D. Nuss described a minimally invasive procedure for surgical repair of Pectus excavatum (PE). Today, the Nuss procedure is performed with increasing frequency worldwide and considered as the “gold standard”. After its introduction, the method experienced numerous modifications such as routine thoracoscopy and/or sternal elevation, increasing safety of the procedure. Placement of multiple bars and/or the so called cross-bar technique were introduced to correct complex CWDs. Standardized pain management, the introduction of cryo-analgesia and a standardized postoperative physiotherapy program including deep breathing exercises facilitate the establishment of an enhanced recovery after surgery (ERAS) process. However, the widespread use of the minimally invasive repair of pectus excavatum (MIRPE) procedure has been associated with a significant number of serious complications. Furthermore, several studies report near-fatal complications, not only during bar placement, but also during bar removal. This review focuses upon the most relevant modifications, including recent published surgical techniques of MIRPE, in order to describe current developments in the field.

Pectus cross bars increase hospital readmission rates due to serous pleural effusion

OBJECTIVE

Pectus Excavatum's (PE) surgical treatment should be patient specific. In this article, we aimed to compare parallel and cross bar variations of the Nuss method and analyze if there is any difference in results.

METHODS

In this study, a total of 891 patients treated with the Nuss method between August 2005 and February 2018 were considered. These were retrieved from a prospectively recorded PE database. Of these, 276 double-bar patients were included in the study. Patients with parallel bars (225 cases) and patients with crossed bars (51 cases) were compared in terms of age, gender, symmetry, family history, additional anomalies, mean operation time, postoperative hospital stay (days) and hospital readmission rate.

RESULTS

The mean age was measured at 20.7 for parallel bar patients and 20.1 for crossed bars patients. There was no statistically significant difference in terms of age, gender, and mean operation time between two groups. On the other hand, statistical significance was found between two groups when analyzing the deformities' symmetry, patients' family history and additional anomalies. The statistically significant difference of postoperative hospital stay between two groups is clinically negligible. Postoperative hospital readmission rates due to serous pleural effusion were found to be significantly increased in patients with crossed bars (p < 0.001).

CONCLUSION

While pleural effusion requiring readmission was statistically more frequent in cross bars, in centers where thoracentesis can be managed, Nuss method can still be applied safely, even in cases with difficult, complex deformities.

LEVEL OF EVIDENCE

III. Treatment study.

Analysis of chest wall elevation after the Nuss procedure using 3D body scanning technique in patients with pectus excavatum

PURPOSE

For the evaluation of the chest wall deformity, we adopted a non-invasive 3D body scanning system. The objective of this study is to evaluate surgical effect on the whole thorax using 3D scanning technique before and after Nuss procedure.

METHODS

We performed 3D body scanning using Structure Sensor (Occipital Inc, USA) in 11 symmetric patients (average age 13 ± 3.2) under general anesthesia before and after Nuss procedure. Using the scanned data, the improved chest wall was analyzed using 3D-Rugle (Medic Engineering, Japan) imaging software. Preoperative and postoperative 3D data were super-imposed and a thoracic elevating distance in the line of the axial and sagittal section through the deepest point was calculated. Pre- and postoperative external sternal angle (ESA) were calculated from the scanned data.

RESULTS

Mean thoracic elevation distance at the deepest point was 38.6 ± 6.1 mm and it was 28.4 ± 5.1 mm and 19.4 ± 4.9 mm at 4 cm and 8 cm cranial side, respectively. Average ESA improved from 3.9 ± 1.6 degrees to 15.0 ± 1.1 degrees after the operation.

CONCLUSION

Chest depression was effectively elevated 39 mm at the deepest point after Nuss procedure. An indirect elevation effect by pectus bars was found on the wide area of the anterior chest.

Wire fracture in postoperative Nuss procedure: a problem that cannot be ignored

BACKGROUND

Surgical stainless wire has been widely used to stabilize pectus bar and ribs in Nuss procedure for pectus excavatum correction. However, wire fracture and its secondary complications are problems easily to be ignored but very important. The purpose of this article was to describe a series of cases with wire breakage, hoping to arouse the attention of worldwide thoracic surgeons to this potential threat, and to share our modifications on the fixation patterns and materials in Nuss procedure.

METHODS

From September 2011 to January 2020, 44 patients underwent Nuss procedure at Chongqing University Three Gorges Hospital. In the initial 25 patients (Group A), each bar was secured by stainless wires, and the latter 19 patients (Group B) received stainless wires and polyblend polyethylene sutures (PDS) in the bar fixation. Patient demographics, Haller index (HI), wire fracture rate, characteristics of the broken wires, and operation time were recorded.

RESULTS

The mean operation age was 8.1±4.3 years in group A and 10.4±2.9 years in group B. There was no statistical difference in HIs between the two groups (P>0.05). The wire fracture occurred in 88.0% of the patients in Group A, while the wires in Group B were all intact. There was no bar displacement or other serious complication requiring surgical intervention in the two groups. The mean operation time of bar removal when encountering wire fracture was 104.6±42.8 minutes, which was significantly higher than that in Group B (P≤0.001).

CONCLUSIONS

The wire fracture in the bar fixation could pose potential hazards to patients deserving special attention from thoracic surgeons. Cancel the wire fixation in the non-stabilizer side while simultaneously using wires and PDS in the pectus bar fixation may achieve the pectus bar stability while overcoming the problem of wire fracture.

Single-centre Indian case series using X or cross bar for Nuss procedure in pectus excavatum

The modified Nuss procedure using two bars lying parallel or non-intersecting is use to correct pectus excavatum with varying degrees of patient satisfaction. This bar placement has its limitation for certain pectus excavatum morphology where the deformity is deep and focal or located below the subxiphoid. We have altered our bar placement so that bars intersects in an X or cross manner for such pectus morphology. We describe the X or cross bar placement and its specific indications based on morphology in a series of five patients from February 2019 until December 2019 with symmetrical focal deformity along the xiphisternum and asymmetric deformity below the xiphoid. The operating time varied from 90 to 120 min. There was no significant postoperative morbidity. They are on follow-up with period ranging from 4 to 15 months from the day of surgery. Early results show the X or cross bar Nuss procedure can be safely performed to achieve a desired long-term morphological correction of symmetric deep focal xiphisternal defects or asymmetric deformity below the xiphoid.

Multiple-bar Nuss operation: an individualized treatment scheme for patients with significantly asymmetric pectus excavatum

Background

Research into multiple-bar Nuss operations for the treatment of wide-range or significantly asymmetric pectus excavatum is rarely reported. This paper aims to explore the curative effects of multiple-bar Nuss operations on wide-range or significantly asymmetric pectus excavatum.

Methods

We reviewed the clinical data of 153 patients with pectus excavatum who were treated in our hospital from September 2006 to August 2014. All the patients had wide-range or significantly asymmetric pectus excavatum and underwent multiple-bar Nuss operations performed by the author.

Results

All 153 patients agreed to undergo the operation. The median age was 17 y (10.2–41 y). The median Haller index was 3.98 (3.2–25). One hundred and fifty-one patients accepted treatment with two bars, and 2 cases accepted treatment with three bars. The median operation time was 123 min (65–500 min), the median blood loss was 20 mL (2–200 mL), and the median postoperative hospital stay was 6 days (3–33 days). The incidence rates of pleural effusion, pneumothorax and hydropneumothorax that required drainage treatment were 0.7% (1/153), 1.3% (2/153) and 3.3% (5/153), respectively. Displacement of a bar occurred in one case, and bar exposure occurred in 7 cases. Therefore, 2 cases had the bars removed early, within 2 years postoperation. One patient with severe depression (Haller index: 8.8) had an unhealed auxiliary incision of the xiphoid process, and although the incision was cured after the early removal of the inferior bar, the deformity recurred. There were no cases of death. Currently, 51.6% (79/153) of the cases have had the bars removed. The most recent follow-up revealed that patients’ median satisfaction score for the surgical correction effect was 9 points (10 points indicated full satisfaction).

Conclusions

For patients with significantly asymmetric and severely deformed pectus excavatum, the multiple-bar Nuss operation not only is safe and effective but can also achieve a better cosmetic appearance. However, we should continue to explore technical improvements.

Outcomes in adult pectus excavatum patients undergoing Nuss repair

Pectus excavatum (PEx) is one of the most common congenital chest wall deformities. Depending on the severity, presentation of PEx may range from minor cosmetic issues to disabling cardiopulmonary symptoms. The effect of PEx on adult patients has not been extensively studied. Symptoms may not occur until the patient ages, and they may worsen over the years. More recent publications have implied that PEx may have significant cardiopulmonary implications and repair is of medical benefit. Adults presenting for PEx repair can undergo a successful repair with a minimally invasive "Nuss" approach. Resolution of symptoms, improved quality of life, and satisfying results are reported.

Trace metal release after minimally-invasive repair of pectus excavatum

Background

Several studies have shown a high incidence of metal allergy after minimally-invasive repair of pectus excavatum (MIRPE). We postulated that MIRPE is associated with a significant release of trace metal ions, possibly causing the allergic symptoms.

Methods

We evaluated the concentration with chromium, cobalt and nickel in blood, urine and tissue in patients prior to MIRPE and in patients who underwent an explantation of the stainless-steel bar(s) after three years.

Results

Our study group consisted of 20 patients (mean age 19 years) who had bar explantation and our control group included 20 patients (mean age 16 years) prior to MIRPE. At the time of bar removal we detected significantly elevated concentrations of chromium and nickel in the tissue compared to patients prior to the procedure (p<0,001). We also found a significant increase in the levels of chromium in urine and nickel in blood in patients three years post MIRPE (p<0,001). Four patients temporarily developed symptoms of metal allergy, all had elevated metal values in blood and urine at explantation.

Conclusions

Minimally-invasive repair of pectus excavatum can lead to a significant trace metal exposure.

Functional exercise capacity and lung function in patients undergoing an early rehabilitation program after the Nuss procedure: a randomized controlled trial

PURPOSE

The aim of this study was to compare the functional exercise capacity and the lung function among patients undergoing early rehabilitation with those submitted to the conventional care after pectus excavatum repair using the Nuss procedure.

METHOD

Patients were randomly allocated to the early rehabilitation group (ERG) who started rehabilitation after surgery and the group of the conventional care (CG) received routine care of the institution. They were evaluated before surgery (preoperative) and in hospital discharge day (postoperative).

RESULTS

Forty patients were evaluated, twenty in each group. All patients presented a significant reduction in FVC, FEV1, and PEF in the postoperative period, there was no statistically significant difference between groups. There was significant different in postoperative functional exercise capacity between the ERG and CG (506.26 ± 66.54 vs 431.11 ± 75.61, p = 0.02) and the difference between distance walked in the preoperative and postoperative period was lower in the ERC than in the CG (76.57 ± 49.41 vs 166.82 ± 70.13, p < 0.001).

CONCLUSION

Patients undergoing the early rehabilitation after the Nuss procedure presented a better postoperative functional exercise capacity in hospital discharge day compared with patients in the conventional group, with no difference in lung function between groups.

Short Nuss bar procedure

The Nuss procedure is now the preferred operation for surgical correction of pectus excavatum (PE). It is a minimally invasive technique, whereby one to three curved metal bars are inserted behind the sternum in order to push it into a normal position. The bars are left in situ for three years and then removed. This procedure significantly improves quality of life and, in most cases, also improves cardiac performance. Previously, the modified Ravitch procedure was used with resection of cartilage and the use of posterior support. This article details the new modified Nuss procedure, which requires the use of shorter bars than specified by the original technique. This technique facilitates the operation as the bar may be guided manually through the chest wall and no additional stabilizing sutures are necessary.

Use of laryngeal mask airway for non-endotracheal intubated anesthesia for patients with pectus excavatum undergoing thoracoscopic Nuss procedure

BACKGROUND

The aim of the present study was to determine the safety and feasibility of the use of laryngeal mask airway (LMA) for non-endotracheal intubated anesthesia for patients with pectus excavatum (PE) undergoing thoracoscopic Nuss procedure.

METHODS

Between July 2015 and December 2015, 30 selected patients with PE were planned to undergo a thoracoscopic Nuss procedure using LMA for non-endotracheal intubated anesthesia in the Guangdong General Hospital. The clinical data were analyzed to evaluate the safety and feasibility of this technique.

RESULTS

Of the 30 selected patients, two were female, the mean age was 16.04±5.09 years and the average Haller index was 3.37±0.88. A total of 27 cases (90%) succeeded at the first attempt, one patient required conversion to an endotracheal tube (ETT) because of continuous air leak. The peripheral O2 saturation (SpO2), end-tidal carbon dioxide (EtCO2) values, heart rate (HR), and mean arterial blood pressure (MAP) remained stable throughout the procedure in all cases. All of the 30 patients were successfully corrected without requiring conversion to an open surgery. Two patients experienced postoperative nausea and one reported a sore throat. Neither gastro-esophageal reflux nor in-hospital mortality occurred.

CONCLUSIONS

The use of LMA for non-endotracheal intubated anesthesia for selected patients with PE undergoing thoracoscopic Nuss procedure is clinically safe and technically feasible.

Vacuum bell therapy

BACKGROUND

For specific therapy to correct pectus excavatum (PE), conservative treatment with the vacuum bell (VB) was introduced more than 10 years ago in addition to surgical repair. Preliminary results using the VB were encouraging. We report on our 13-year experience with the VB treatment including the intraoperative use during the Nuss procedure and present some technical innovations.

METHODS

A VB with a patient-activated hand pump is used to create a vacuum at the anterior chest wall. Three different sizes of vacuum bells, as well as a model fitted for young women, exist. The appropriate size is selected according to the individual patient's age and ventral surface. The device should be used at home for a minimum of 30 minutes (twice a day), and may be used up to a maximum of several hours daily. The intensity of the applied negative pressure can be evaluated with an integrated pressure gauge during follow-up visits. A prototype of an electronic model enables us to measure the correlation between the applied negative pressure and the elevation of the anterior chest wall.

RESULTS

Since 2003, approx. 450 patients between 2 to 61 years of age started the VB therapy. Age and gender specific differences, depth of PE, symmetry or asymmetry, and concomitant malformations such as scoliosis and/or kyphosis influence the clinical course and success of VB therapy. According to our experience, we see three different groups of patients. Immediate elevation of the sternum was confirmed thoracoscopically during the Nuss procedure in every patient.

CONCLUSIONS

The VB therapy has been established as an alternative therapeutic option in selected patients suffering from PE. The initial results up to now are encouraging, but long-term results comprising more than 15 years are so far lacking, and further evaluation and follow-up studies are necessary.

The measurement of the normal thorax using the Haller index methodology at multiple vertebral levels

The Haller index is a ratio of thoracic width and height, measured from an axial CT image and used to describe the internal dimensions of the thoracic cage. Although the Haller index for a normal thorax has been established (Haller et al. 1987; Daunt et al. 2004), this is only at one undefined vertebral level in the thorax. What is not clear is how the Haller index describes the thorax at every vertebral level in the absence of sternal deformity, or how this is affected by age. This paper documents the shape of the thorax using the Haller index calculated from the thoracic width and height at all vertebral levels of the thorax between 8 and 18 years of age. The Haller Index changes with vertebral level, with the largest ratio seen in the most cranial levels of the thorax. Increasing age alters the shape of the thorax, with the most cranial vertebral levels having a greater Haller index over the mid thorax, which does not change. A slight increase is seen in the more caudal vertebral levels. These data highlight that a 'one size fits all' rule for chest width and depth ratio at all ages and all thoracic levels is not appropriate. The normal range for width to height ratio should be based on a patient's age and vertebral level.

Non-surgical treatment of pectus excavatum

BACKGROUND

Previously used procedures to correct pectus excavatum (PE) were largely based on surgical techniques like Ravitch procedure or the minimally invasive Nuss technique. Conservative treatment with the vacuum bell (VB) to elevate the funnel in patients with PE, represents a potential alternative to surgery in selected patients.

METHODS

A suction cup is used to create a vacuum at the anterior chest wall. Three different sizes as well as a model fitted for young women of VB exist which are selected according to the individual patients age. A patient-activated hand pump is used to create a vacuum at the anterior chest wall. When creating the vacuum, the lift of the sternum is obvious and remains for a different time period. The device should be used for a minimum of 30 minutes (2/day), and may be used up to a maximum of several hours daily. We have an IRB approval for it. Since this paper was conducted as a retrospective study, we did not have to have informed consent of every patient.

RESULTS

CT-scans showed that the device lifted the sternum and ribs immediately. In addition, this was confirmed thoracoscopically during the MIRPE procedure. Preliminary results published within the last 10 years proved to be successful.

CONCLUSIONS

The VB has been established as an alternative therapeutic option in selected patients suffering from PE. The initial results proved to be dramatic, but long-term results comprising more than 15 years are so far lacking, and further evaluation and follow-up studies are necessary.