Brachial plexus endoscopy: feasibility study on cadavers

The development of a minimally invasive technique for exploration of the brachial plexus seems a logical step towards refinement of diagnosis and treatment. For certain pathological conditions, minimally invasive techniques have become the method of choice; for others, they remain as an ancillary option for assistance during open surgery. We have developed a full endoscopic technique for brachial plexus exploration. Our endoscopic technique used saline liquid infusion in seven brachial plexus of four cadavers. Five portals have been described and the endoscopic landmarks also. We were able to demonstrate excellent views and adequate possibilities for cadaver plexus dissection and its anatomic landmarks and portals. LEVEL OF EVIDENCE: 4.     

Endoscopic exploration of the brachial plexus: technique and topographic anatomy--a study in fresh human cadavers

OBJECTIVE: The indications for and timing of brachial plexus exploration in closed injuries are controversial. The time-consuming surgery proves its worth in some cases, whereas spontaneous regeneration might have been possible in others. The differentiation is difficult, because no investigational method reveals the exact morphological correlates of the nerve lesions. Minimally invasive, direct observation of the structures is a possible solution. Here we describe our surgical technique and the anatomic features of the normal brachial plexus appreciated with the endoscope. METHODS: Twenty-one brachial plexus in 11 fresh cadavers were investigated. Endoscopic exploration was performed at the supraclavicular and infraclavicular levels. The method involves insertion of an optic shaft-integrated retractor through a stab wound; retraction of landmark muscles produces a working space, into which other instruments are introduced for dissection. After completion of endoscopic surgery, open dissection was performed to verify the endoscopically identified structures and to assess iatrogenic injuries. RESULTS: The omohyoid muscle is a reliable landmark in the supraclavicular region, beneath which the suprascapular nerve can be observed. Following the suprascapular nerve proximally leads to the plexus trunks. Infraclavicular exploration first reveals the axillary artery. The plexus and its nerves are traced around this artery. The anatomic features were constant in all cases, with variations in fat accumulation depending on the corporeal constitution. We detected iatrogenic injuries to the medial circumflex humeral vessels in two cases. No nerve injuries were observed. CONCLUSION: The endoscopic technique combined with intraoperative nerve stimulation studies might provide important information on the type of morphological damage in closed brachial plexus injuries and thus might become an important tool for determination of the surgical treatment strategy. Clinical work is under way.     

Modification of the Zitelli bilobed flap: a comparison of flap dynamics in human cadavers

OBJECTIVE: To investigate the effects on overall flap dynamics of altering the length of the primary flap in the Zitelli bilobed flap procedure, because the standard Zitelli design can result in distortion of the alar margin after repair of cutaneous nasal alar defects. METHODS: Identical 1.5-cm circular cutaneous defects were made on the nasal alae and cheeks of 6 fresh human cadavers. A rectangle was inked around each cheek defect in a standardized fashion. A standard-design Zitelli bilobed flap was used to close the nasal and cheek defects on 1 side of each specimen (n = 6). The contralateral defect was closed with a modified design in which the primary flap was either 10% longer (n = 3) or 10% shorter (n = 3) than the standard primary flap as measured from the pivot point. Alar margin retraction and cheek defect distortion were measured from standardized photographs obtained before and after the repair. RESULTS: The long-flap design resulted in alar retraction that was 1.33 mm less in the nasal reconstructions (P = .02) and distal defect distortion that was 2.17 mm less in the cheek reconstructions (P = .01) compared with the standard Zitelli bilobed flap. The short-flap design caused more distortion than did the standard design for both types of defect. CONCLUSION: Lengthening the primary flap in the Zitelli bilobed flap design may reduce distal wound distortion and alar retraction in the closure of certain cutaneous defects.     

Ultrasound-based navigated pedicle screw insertion without intraoperative radiation: feasibility study on porcine cadavers

BACKGROUNDNavigation systems for spinal fusion surgery rely on intraoperative computed tomography (CT) or fluoroscopy imaging. Both expose patient, surgeons and operating room staff to significant amounts of radiation. Alternative methods involving intraoperative ultrasound (iUS) imaging have recently shown promise for image-to-patient registration. Yet, the feasibility and safety of iUS navigation in spinal fusion have not been demonstrated.PURPOSETo evaluate the accuracy of pedicle screw insertion in lumbar and thoracolumbar spinal fusion using a fully automated iUS navigation system.STUDY DESIGNProspective porcine cadaver study.METHODSFive porcine cadavers were used to instrument the lumbar and thoracolumbar spine using posterior open surgery. During the procedure, iUS images were acquired and used to establish automatic registration between the anatomy and preoperative CT images. Navigation was performed with the preoperative CT using tracked instruments. The accuracy of the system was measured as the distance of manually collected points to the preoperative CT vertebral surface and compared against fiducial-based registration. A postoperative CT was acquired, and screw placements were manually verified. We report breach rates, as well as axial and sagittal screw deviations.RESULTSA total of 56 screws were inserted (5.50 mm diameter n=50, and 6.50 mm diameter n=6). Fifty-two screws were inserted safely without breach. Four screws (7.14%) presented a medial breach with an average deviation of 1.35±0.37 mm (all <2 mm). Two breaches were caused by 6.50 mm diameter screws, and two by 5.50 mm screws. For vertebrae instrumented with 5.50 mm screws, the average axial diameter of the pedicle was 9.29 mm leaving a 1.89 mm margin in the left and right pedicle. For vertebrae instrumented with 6.50 mm screws, the average axial diameter of the pedicle was 8.99 mm leaving a 1.24 mm error margin in the left and right pedicle. The average distance to the vertebral surface was 0.96 mm using iUS registration and 0.97 mm using fiducial-based registration.CONCLUSIONSWe successfully implanted all pedicle screws in the thoracolumbar spine using the ultrasound-based navigation system. All breaches recorded were minor (<2 mm) and the breach rate (7.14%) was comparable to existing literature. More investigation is needed to evaluate consistency, reproducibility, and performance in surgical context.CLINICAL SIGNIFICANCEIntraoperative US-based navigation is feasible and practical for pedicle screw insertion in a porcine model. It might be used as a low-cost and radiation-free alternative to intraoperative CT and fluoroscopy in the future.     

Comparison of two techniques for retrograde tracheal intubation in human fresh cadavers

BACKGROUND: During retrograde tracheal intubation, the short distance existing between the cricothyroid membrane and vocal cords may be responsible for accidental extubation. The insertion of a catheter into the trachea before the removal of the guide wire may help to cope with this problem. This work was conducted to study the impact of such a modification on the success rate and the duration of the procedure. METHODS: Procedures of retrograde tracheal intubation following the classic and modified techniques were randomly performed in cadavers (n = 70). The duration of the procedure from the puncture of the cricothyroid membrane to the inflation of the balloon of the endotracheal tube was measured, and, at the end of the procedure, the position of the endotracheal tube was checked under laryngoscopy. The procedure was considered to have failed if it had taken more than 5 min or when the endotracheal tube was not positioned in the trachea. RESULTS: The mean time to achieve tracheal intubation was similar in both groups (123 +/- 51 vs. 127 +/- 41 s; not significant), but intubation failed significantly more frequently with the classic technique (22 vs. 8 failures; P < 0.05). All failures were related to incorrect positioning of the endotracheal tube. In four cases, both techniques failed. CONCLUSIONS: This efficient, simple modification of the technique significantly increases the success rate of the procedure, without prolonging its duration. These data should be confirmed in clinical conditions but may encourage a larger use of the retrograde technique in cases of difficult intubation.     

The impact of Pfannenstiel scars on TRAM flap complications

For the past two decades, the transverse rectus abdominis musculocutaneous (TRAM) flap has been a mainstay of postmastectomy breast reconstruction. Because the flap depends on musculocutaneous perforating vessels from the rectus muscle for survival, some authors have raised concerns about increased risks of TRAM flap loss in patients with scars from previous abdominal surgeries, particularly those with Pfannenstiel scars. To assess the effects of Pfannenstiel scars on complication rates, we retrospectively evaluated the inpatient and outpatient records of 241 patients undergoing TRAM reconstruction in a single institution over an 11-year period. Of these patients, 51 had previous Pfannenstiel scars. while 190 did not. Controlling for potential confounding variables (body mass index and timing of reconstruction), logistic regressions found no significant differences between the Pfannenstiel and nonPfannenstiel cohorts in the rate of flap loss (15.7% and 20%, respectively; P = 0.376) or in the incidence of postoperative abdominal donor site laxity (17.6% and 12.1%, respectively; P= 0.361). Within the Pfannenstiel group, the type of TRAM reconstruction (ie, pedicle versus free flaps) did not have a significant effect on complication rates. We conclude that previous concerns over the impact of preexisting Pfannenstiel scars on TRAM flap complications are unfounded.     

上、下蒂横形腹直肌肌皮瓣乳房再造的解剖学研究

目的探讨上蒂横形腹直肌肌皮瓣乳房再造术后并发症产生的原因。方法对２０侧成人尸体进行解剖观察。结果发现主要是由于上蒂术式切断了该肌皮瓣的主要供血动脉——腹壁下动脉，仅靠腹壁上、下动脉之间微薄的螺旋微动脉的吻合支供血，以致术后产生脂肪液化、边缘坏死等并发症。结论腹壁下动、静脉是中、下腹部横形腹直肌肌皮瓣的直接供血动脉及回流静脉，即下蒂优于上蒂。     

Preoperative Angio-CT preliminary study of the TRAM flap after selective vascular delay

BACKGROUND: The pedicled TRAM (pTRAM) flap is one of the best options for autologous breast reconstruction, but vascular complications reported in the standard versions are about 30%. To reduce complication rate, especially in high-risk patients, surgical delay has been suggested.Individual precise preoperative location and evaluation of perforating vessels and of variations of the diameter of the deep superior epigastric artery (DSEA) are highly desirable for improving surgical strategy. Previous reports using color duplex scanning, although generally confirming the validity of the delay maneuver, have showed several pitfalls. The aim of this report was to demonstrate the usefulness of multidetector computed tomography angiography (MDCTA) for preoperative planning in patients undergoing pTRAM flap breast reconstruction after selective vascular delay. METHODS: Three patients were considered for breast reconstruction with the pTRAM flap. An MDCTA was performed before and after selective delay to locate the muscle perforators and to show increase in DSEA diameter. Axial images, multiplanar reconstruction, and 3D volume images were analyzed. RESULTS: Accurate identification of the main perforators was achieved. Location, course, and anatomic variations of DSEA were reported. The average increase in diameter of the DSEA was 29.3%. CONCLUSION: Preoperative planning of pTRAM flap with MDCTA allows surgeons to visualize and locate the dominant perforators and to select the best DSEA. Consequently, the choice between the homolateral or contralateral rectus muscle is facilitated. The high sensitivity and specificity and the ease of interpreting data have made MDCTA a highly promising diagnostic tool for planning a pTRAM flap.     

上、下蒂横形腹直肌肌皮瓣乳房再造的解剖学研究

目的探讨上蒂横形腹直肌肌皮瓣乳房再造术后并发症产生的原因。方法对20侧成人尸体进行解剖观察。结果发现主要是由于上蒂术式切断了该肌皮瓣的主要供血动脉——腹壁下动脉,仅靠腹壁上、下动脉之间微薄的螺旋微动脉的吻合支供血,以致术后产生脂肪液化、边缘坏死等并发症。结论腹壁下动、静脉是中、下腹部横形腹直肌肌皮瓣的直接供血动脉及回流静脉,即下蒂优于上蒂。     

Risk factors and blood flow in the free transverse rectus abdominis (TRAM) flap: smoking and high flap weight impair the free TRAM flap microcirculation

Mastectomy patients may have significant psychologic-related problems. Breast reconstruction provides in these cases substantial benefits in restoring body image and health-related quality of live. Autologous free tissue transfer is the treatment of choice due to excellent outcome. The purpose of this study was to elucidate the effect of the risk factors on the microcirculation and clinical outcome.In this prospective study, 21 patients with a free transverse rectus abdominis (TRAM) flap breast reconstruction were included. Patient demographics and flap characteristics were recorded. Blood flow was recorded in the central part (zone I) and the distal part (zone IV) of the flap with the laser Doppler flowmetry (LDF; Perimed).In this study, increased flap complications were seen in smokers when compared with nonsmokers (P < 0.000). LDF was higher in the older patient population (P = 0.008) in zone IV. Smoking, especially in combination with a high flap weight (HFW), revealed lower blood-flow values (P = 0.020) in zone IV. Other possible influencing risk factors such as a HFW and history of radio- and chemotherapy did not alter the microcirculation. Patients with smoking and a HFW did also show decreased blood flow but also more severe flap complications.Smoking, especially in patients with a HFW, impairs the free TRAM flap microcirculation in zone IV. In our opinion, these patients can still be included for reconstruction. However, extra care has to be taken during flap design to minimize disturbed wound healing.     

The augmented TRAM flap: a technique for the large-breasted patients

The transverse rectus abdominis myocutaneous (TRAM) flap is the most common method of autogenous breast reconstruction. In high-risk patients, a reliable and bulky flap is needed to achieve breast symmetry and a mound together with durable satisfactory projection. The purpose of this study is to look into the use of contralateral zones of the pedicled TRAM flap to improve flap survival and to reduce the incidence of fat necrosis in order to achieve good cosmetic results. Seven obese large-breasted patients of cup size C and above who underwent primary breast reconstruction by the same surgeon are presented. In each case, all the four zones of the TRAM flap were used to achieve symmetry of the reconstruction. Patients had mastectomy with or without axillary clearance. The pedicled TRAM flap was elevated and the other side was raised as a perforator flap for microvascular augmentation. The perforator vascular pedicle was anastomosed to the thoracodorsal vessels in all cases. The anterior rectus sheath was repaired with a mesh in all cases. All the flaps were coned to achieve a good projection. All flaps survived with no complications or loss. All patients were satisfied with the outcome. One of our patients developed an abdominal bulge that was treated conservatively. Microvascular augmentation improved survival of zones III and IV of the TRAM flap, exemplified by flap survival and no incidence of fat necrosis. It is a good reconstructive tool to achieve breast volume, symmetry, and projection. In addition, it reduces the need of secondary breast surgery for the contralateral breast in the future.     

The extraperitoneal laparoscopic TRAM flap delay procedure: an alternative approach

Introduction  

Ligation of the deep inferior epigastric vessels prior to transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction (delay procedure) was introduced to augment vascularity to the island flap through improved superior epigastric flow, thus decreasing flap morbidity. There are various surgical approaches described, including open and laparoscopic approaches, for ligation of inferior epigastric arteries. We describe an extraperitoneal laparoscopic technique (EPLT) and the outcomes of the procedure.