SciCombinator

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Journal: Journal of reconstructive microsurgery

28

Nerve conduits have emerged as alternatives to autologous nerve grafts, but their use in large-diameter, critical nerve repairs is limited. In the previous study, we prepared a PRGD/PDLLA/β-TCP/NGF sustained-release nerve conduit, which was made of RGD peptide modified poly{(lactic acid)-co-[(glycolic acid)-alt-(L-lysine)]} (PRGD), poly(d,l-lactic acid) (PDLLA), β-tricalcium phosphate (β-TCP) and nerve growth factor (NGF). Here we attempted to use the PRGD/PDLLA/β-TCP/NGF sustained-release nerve conduit to bridge a 30-mm dog tibial nerve defect in six beagles. The other beagles were divided into group autograft (n = 6) as positive control and group PDLLA (n = 6) as negative control. After 9 months of implantation, nerve conduction velocities, the density of myelinated fibers, the mean diameter of axon, and the average thickness of myelin sheath in tibial nerves bridged with PRGD/PDLLA/β-TCP/NGF sustained-release nerve conduits were similar to those treated with autologous nerve (p > 0.05). Neither electrophysiological nor histological restoration was obtained in group PDLLA. Evidence is thus provided in support of the use of PRGD/PDLLA/β-TCP/NGF sustained-release nerve conduits as alternatives to autologous nerve grafts for treatment of large-diameter, critical defects in peripheral nerves.

Concepts: Tibial nerve, Saltatory conduction, Nerve growth factor, Myelin, Nerve conduction study, Axon, Nervous system, Action potential

27

The authors described a modified pathological classification (PC) of brachial plexus injury (BPI) and its magnetic resonance (MR) imaging characteristics. The reliability and diagnostic accuracy of MR imaging for detecting nerve injury was discussed. Between 2006 and 2010, 86 patients with BPI were managed surgically in our department. Their preoperative MR images and surgical findings were analyzed retrospectively. The PC of BPI was classified into five types: (I) nerve root injury in continuity (including Sunderland grade I-IV injury); (II) postganglionic spinal nerve rupture with or without proximal stump; (III) preganglionic root injury (visible); (IV) preganglionic nerve root injury and postganglionic spinal nerves injury; (V) preganglionic root injury (invisible). The main MR imaging characteristics of BPI included traumatic meningocele, displacement of spinal cord, the absence of nerve root, “Black line” sign, nerve root/trunk injury in continuity, and thickening and edema of nerve root. The accuracy of MR imaging for detecting C5, C6, C7, C8, and T1 nerve roots injury were 93.3, 95.2, 92.3, 84, and 74.4%, respectively. The modified PC provides a detailed description of nerve root injury in BPI, and MR imaging technique is a reliable method for detecting nerve root injury.

Concepts: Nervous system, Reliability, Surgery, Spinal cord, Magnetic resonance imaging, Brachial plexus, Nerve, Spinal nerve

27

The use of medicinal leeches in reconstructive surgery has proven value for the salvage of flaps with venous congestion but is associated with a risk of leech-acquired infection. The most common leech-associated organism is Aeromonas hydrophila, which antibiotic prophylaxis is typically directed against. The authors describe two new multidrug-resistant organisms acquired from medicinal leech therapy that resulted in flap infection. The evaluation of suspected leech-borne infection and management protocol for this leech-acquired resistant multi-organism infection is presented.

Concepts: Antibiotic resistance, Biology, Virus, Medicine, Bacteria, Surgery, Leech, European Medical Leech

27

Background The anterolateral thigh (ALT) flap has been widely used in reconstruction of soft tissue defects. The anatomic variations of perforators increase the difficulties of flap elevation. The ABC system has been described for locating the most common three perforators in Western populations. Less evidence has been found regarding whether it is suitable for Chinese population. The purpose of this study is to explore the improvement of preoperative location technology and flap design for Chinese people.Methods Detection for perforator signals on the bilateral thigh surface was perfromed on 50 Chinese adults using handheld Doppler. Define the A-P line as the line between the anterior superior iliac spin (ASIS) and the superolateral corner of the patella (P). We defined a coordinate system on the thigh surface to record the data of each signal point. The A-P line was y-axis in this coordinate system, and the midpoint of the line was the zero point. The data of these signals were recorded in the form of coordinates. Statistics and mathematic methods were used to analyze the regularity of signal distribution and the correlation between body mass index (BMI) and signal distribution. The findings were applied in five patients who underwent the ALT flap transplantation to confirm its clinical value.Results The results showed that most of the signals appeared near the A-P line. Most signals were located 1 cm lateral (mean 0.5 cm lateral) to the A-P line. The mean vertical distance between perforator B and perforators A and C was 4 cm . More perforator signals were detected at the two horizontal level (as shown in the picture above) than other horizontal levels. The rate of accurate preoperative detection was 40% (6 of 15 perforators) and the error rate was 20% (3 of 15 perforators). The mean deviation was 1.34 cm, which is acceptable for clinical application. The mean vertical distance between perforator B and perforators A and C in clinical study (4.81 cm) corresponded to the finding of the Doppler study (4.2 cm), whereas the mean distance between perforators and the A-P line (1.57 cm) was more than the Doppler finding (0.48 cm).Conclusion The A-P line is still a reliable guiding line for Doppler detection and flap design. The ABC system is suitable for the Chinese population but must be adjusted: perforator B is marked first at the midpoint and 0.5 cm lateral to the A-P line and perforators A and C are marked 4 cm distal and proximal to perforator B, respectively. In designing the flap, the region 3 cm around point B and the region between the two horizontal planes at point B and 4 cm lower should both be contained into the flap, no matter what the finding of Doppler detection is.

Concepts: Deviation, Horizontal plane, People's Republic of China, Absolute deviation, Pelvis, Coordinate system, Body mass index, Analytic geometry

27

Background The authors describe our current practice of computer-aided virtual planned and pre-executed surgeries using microvascular free tissue transfer with immediate placement of implants and dental prosthetics.Methods All patients with ameloblastomas treated at New York University (NYU) Medical Center during a 10-year period from September 2001 to December 2011 were identified. Of the 38 (36 mandible/2 maxilla) patients that were treated in this time period, 20 were identified with advanced disease (giant ameloblastoma) requiring aggressive resection. Reconstruction of the resultant defects utilized microvascular free tissue transfer with an osseocutaneous fibular flap in all 20 of these patients.Results Of the patients reconstructed with free vascularized tissue transfer, 35% (7/20) developed complications. There were two complete flap failures with consequent contralateral fibula flap placement. Sixteen patients to date have undergone placement of endosteal implants for complete dental rehabilitation, nine of which received immediate placement of the implants at the time of the free flap reconstruction. The three most recent patients received immediate placement of dental implants at the time of microvascular free tissue transfer as well as concurrent placement of dental prosthesis.Conclusions To our knowledge, this patient cohort represents the largest series of comprehensive computer aided free-flap reconstruction with dental restoration for giant type ameloblastoma.

Concepts: Dentistry, Implants, Periodization, CAD/CAM Dentistry, Free flap, Dental implant, Computer-aided design, Oral and maxillofacial surgery

24

Background The lateral branch of the thoracodorsal nerve (LBTN) is used for nerve transfer in facial, musculocutaneous, axillary nerve injuries and for irreparable C5, C6 spinal nerve lesions and accessory nerve defects. For a successful surgical outcome, the nerve to be used in nerve transfer should be of adequate length and thickness for nerve coaptation. Aim Our objective was to evaluate the length of the LBTN that could be obtained as a donor nerve, externally and within the muscle. Method Eight (8) cadavers with intact upper limbs and thorax which could be positioned in the anatomical position were selected for the study. Cadavers with dissected axillae, brachial plexus or upper limbs were excluded. The thoracodorsal neurovascular bundle was dissected and the number of branches of the thoracodorsal nerve was identified along with its lateral branch. The lateral branch was dissected up to the latissimus dorsi muscle and further intramuscularly. All lengths were measured using a vernier caliper. Results The mean length of the LBTN, up to its first intramuscular branch, is 8.14 cm (range 5.99-12.29 cm). Beyond this, the intramuscular nerve branched further and was of very minute diameter. The mean unbranched intramuscular length of the nerve is 3.36 cm (range 1.3-7.71 cm) which is 41.28% of the total length of the LBTN. Conclusion A significant proportion of the LBTN is found within the latissimus dorsi muscle. This length could potentially be used for direct nerve coaptation by intrafascicular dissection.

Concepts: Nerves of the upper limb, Axillary artery, Dissection, Axillary nerve, Posterior cord, Thoracodorsal nerve, Latissimus dorsi muscle, Brachial plexus

4

Background Phrenic nerve reconstruction has been evaluated as a method of restoring functional activity and may be an effective alternative to diaphragm plication. Longer follow-up and a larger cohort for analysis are necessary to confirm the efficacy of this procedure for diaphragmatic paralysis. Methods A total of 180 patients treated with phrenic nerve reconstruction for chronic diaphragmatic paralysis were followed for a median 2.7 years. Assessment parameters included: 36-Item Short Form Health Survey (SF-36) physical functioning survey, spirometry, chest fluoroscopy, electrodiagnostic evaluation, a five-item questionnaire to assess specific functional issues, and overall patient-reported outcome. Results Overall, 134 males and 46 females with an average age of 56 years (range: 10-79 years) were treated. Mean baseline percent predicted values for forced expiratory volume in 1 second, forced vital capacity, vital capacity, and total lung capacity, were 61, 63, 67, and 75%, respectively. The corresponding percent improvements in percent predicted values were: 11, 6, 9, and 13% (p ≤ 0.01; ≤ 0.01; ≤ 0.05; ≤ 0.01). Mean preoperative SF-36 physical functioning survey scores were 39%, and an improvement to 65% was demonstrated following surgery (p ≤ 0.0001). Nerve conduction latency, improved by an average 23% (p ≤ 0.005), and there was a corresponding 125% increase in diaphragm motor amplitude (p ≤ 0.0001). A total of 89% of patients reported an overall improvement in breathing function. Conclusion Long-term assessment of phrenic nerve reconstruction for diaphragmatic paralysis indicates functional correction and symptomatic relief.

Concepts: Lung, Improve, Lung volumes, Vital capacity, Thoracic diaphragm, Spirometry, Phrenic nerve, Respiratory physiology

2

Background Lymphedema is a well-known sequela of breast but no consensus has been reached about the ideal treatment. Surgical approaches, however, are receiving increased attention. Various microsurgical reconstructive techniques aim to restore anatomy and function of the lymphatic system in upper limb breast cancer-related lymphedema (BCRL). We combined two techniques, lymphaticovenous anastomosis (LVA) and autologous lymph node transplantation (ALNT) after carefully selecting those who may benefit from the surgery. We called this the “combined surgical treatment (CST)” approach. Methods From June 2007 to December 2011, we performed CST in 106 patients with upper limb BCRL. Clinical evaluation and diagnostic imaging studies were performed preoperatively in all the patients. CST was offered to patients with stage I/II lymphedema, according to the criteria of the International Society of Lymphology (ISL). Results Overall 59 of the 106 patients underwent LVA, 7 underwent ALNT, and 40 underwent both the techniques. All 47 lymph node (LN)-flaps survived but 11 (22%) required surgical revision within 3 days. A total of 21 LN-flaps (45%) showed no radiotracer uptake at 1 year. Around 1 to 7 LVAs for each patient (average 3.4) were performed. Preoperative versus postoperative excess circumference decreased between 12 and 86.7% (average 39.72%). Arm circumference decreased between 0.9 and 6.1 cm (average 2.75 cm). The number of episodes of lymphangitis per year decreased from 1.8 to 0.2. Conclusion Preoperative assessment is essential to select patients who can benefit from surgery for lymphedema and to choose the best surgical approach in each case. Our satisfactory results in well-selected cases encourage further research into surgical treatment for BCRL.

Concepts: Lymph vessel, Lymph node, Surgery, Lymph, Lymphatic system

1

 Profunda artery perforator (PAP) flap breast reconstruction has emerged as a popular choice for patients who are not optimal candidates for autologous breast reconstruction using abdominal-based techniques such as the deep inferior epigastric perforator flap. Despite increased utilization of PAP flaps, there are no previous studies on the donor-site morbidity. In this study, we present risk factors, classification of thigh wounds, and our management of donor-site wounds.

1

 Increased rates of both breast cancer and obesity have resulted in more obese women seeking breast reconstruction. Studies demonstrate that these women are at increased risk for perioperative complications. A systematic review was conducted to assess the outcomes in obese women who underwent breast reconstruction following mastectomy.

Concepts: Endocrine disruptor, Overweight, Metastasis, Nutrition, Breast cancer, Breast, Obesity, Cancer