Microsurgical breast reconstruction and primary hypercoagulable disorders.

BACKGROUND: Primary hypercoagulable disorders pose a significant challenge to microsurgeons and have traditionally been regarded as a relative contraindication to free tissue transfer. Since free flaps offer numerous advantages in breast reconstruction, there is an effort to expand the population to whom these operations can be safely offered. The purpose of this study is to describe our chemoprophylaxis regimen in cases of primary hypercoagulability, as well as to compare flap outcomes and complications between women with and without hypercoagulability. PATIENTS AND METHODS: A single institution retrospective review identified 15 patients (25 flaps) with known primary hypercoagulability who underwent microsurgical breast reconstruction from 2010 through 2020. There were 785 patients (1268 flaps) without primary hypercoagulability who underwent microsurgical breast reconstruction, including 40 patients (73 flaps) with a history of venous thromboembolism (VTE), evaluated for comparison. Patient characteristics, thromboprophylaxis regimen, and surgical outcomes were collected. In carrying out this cohort study, we have adhered to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. RESULTS: Fifteen patients with primary hypercoagulability were identified, including heterozygous factor V Leiden mutation (n = 12), protein S deficiency (n = 1), prothrombin mutation (n = 1), and primary antiphospholipid syndrome (n = 1). Thirteen of these (87%) were discharged with an extended LMWH course. There was no postoperative VTE or mortality in this cohort, and no significant difference in hematoma or transfusion compared with the control group (p = .31, p = .87, respectively). The flap loss rate was 4% in the hypercoagulable group compared with 0.92% in the control group (p = .15). The salvage for arterial or venous compromise in the hypercoagulable group was poor (0% vs. 52%, p = .3). CONCLUSION: Microsurgical breast reconstruction in women with primary hypercoagulability disorders is feasible with acceptable risk of flap loss but poor salvage potential. Postoperative thromboprophylaxis with extended prophylactic LMWH in this population appears to be a safe regimen.

Heparin-induced thrombocytopenia in lower extremity free tissue transfers.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) an immunologically mediated reaction to heparin products, can lead to severe thrombocytopenia and potentially life-threatening thrombotic events. In microsurgery, a missed or delayed diagnosis of HIT can cause complications requiring revision operations, flap loss, or limb loss. Surgeons must remain vigilant for this uncommon yet potentially devastating condition and keep abreast of management strategies. METHODS: CPT and ICD-10 codes in electronic medical records were used to collect demographic information, clinical courses, and outcomes for patients with a HIT diagnosis who underwent lower extremity free tissue transfer in one institution. RESULTS: The authors' institution performed 415 lower extremity free flaps in 411 patients during the 10-year study period. Flap salvage rate was 71% for compromised lower extremity flaps without HIT, and 25% in those with HIT. Four patients (four flaps) met study inclusion criteria during the study period. Three of the four flaps failed and were later debrided; one was rescued after a takeback for anastomosis revision. Two patients successfully underwent a delayed second free flap procedure after recovery, and one was salvaged with a pedicled muscle flap. CONCLUSIONS: Surgeons should monitor for HIT by establishing coagulation panel and platelet count baselines and trending these values in the early post-operative period for patients treated with heparin products. The 4T score can be used to screen for HIT with high clinical suspicion. Arterial thrombosis or poor flap perfusion despite sound microvascular technique could suggest HIT. Surgical and medical management including strict heparin avoidance can prevent adverse events for these patients.

Rates of major complications and flap loss for abdominally based breast reconstruction in obese patients are independent of WHO class of obesity.

INTRODUCTION: Obesity is a risk factor for complications following autologous breast reconstruction. Little is known regarding outcomes based on the degree of obesity. This study compares breast reconstruction outcomes and complication rates for the three classes defined by the body mass index (BMI)-based WHO classification. METHODS: The authors conducted a retrospective chart review identifying obese patients who underwent abdominally based breast reconstruction between January 2011 and January 2021. Patients were stratified by BMI class [class 1 (C1) = 30-34.99 kg/m2, class 2 (C2) = 35-39.99 kg/m2, and class 3 (C3) = 40 kg/m2 + ]. Outcomes were compared. RESULTS: A total of 232 patients (395 flaps) were included with 138 patients were classified as C1, 68 patients as C2, and 26 patients as C3. Rates of any complication (80%) and at least one major complication (31%) did not vary significantly (P = 0.057, 0.185). Individual rates of 30-day readmission (18%) or reoperation (26%) did not vary significantly (P = 0.588 and 0.059). Rates of seroma (C1 = 15%, C2 = 16%, and C3 = 35%), hernia (C1 = 0%, C2 = 4%, and C3 = 8%), and incisional dehiscence (C1 = 30%, C2 = 44%, and C3 = 62%) were associated with significantly increased risk with higher classes of obesity (P < 0.05). The rate of flap failure did not vary significantly (P = 0.573). CONCLUSION: The risk of major complications and total flap loss associated with abdominally based breast reconstruction does not differ between the classes of obesity. Although complication rates are high overall in the obese population, detrimental complications do not vary between the classes. Patients should be counseled regarding their individual risk without the need for arbitrary BMI cutoffs.

Early evaluation of nerve regeneration after nerve injury and repair using functional connectivity MRI.

Resting state functional connectivity magnetic resonance imaging studies in rat brain show brain reorganization caused by nerve injury and repair. In this study, distinguishable differences were found in healthy, nerve transection without repair (R-) and nerve transection with repair (R+) groups in the subacute stage (2 weeks after initial injury). Only forepaw on the healthy side was used to determine seed voxel regions in this study. Disturbance of neuronal network in the primary sensory region of cortex occurs within two hours after initial injury, and the network pattern was restored in R+ group in subacute stage, while the disturbed pattern remained in R- group. These are the central findings of the study. This technique provides a novel way of detecting and monitoring the effectiveness of peripheral nerve injury treatment in the early stage and potentially offers a tool for clinicians to avoid poor clinical outcomes.

C7 nerve root sensory distribution in peripheral nerves: a bold functional magnetic resonance imaging investigation at 9.4 T.

INTRODUCTION: In this study we used a rat model to elucidate the linear make-up of each major nerve of the upper limb by the C7 root through sensory stimulation and functional magnetic resonance imaging (fMRI). METHODS: The C7 nerve root and major nerves of the right forelimb were stimulated electrically. Blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) was performed concurrently. Voxel overlap within the primary sensory cortex was calculated. RESULTS: C7 comprised sensation in <1% in the musculocutaneous nerve, 6% in the ulnar nerve, 16% in the radial nerve, and 19% in the median nerve (P<0.005 for each). The overlap was always <25% for each major nerve. CONCLUSIONS: This study helps explain why C7 is a suitable donor for brachial plexus injury treatment and why there is only a transient sensory deficit after transfer.

Le Fort III distraction using rotation advancement of the midface in patients with cleft lip and palate.

BACKGROUND: Patients with cleft lip and palate demonstrate a spectrum of maxillary growth deficiencies. The purpose of this study was to review the authors' experience in the treatment of midface hypoplasia in nonsyndromic cleft lip-cleft palate patients using rotation advancement of the midface with Le Fort III distraction. METHODS: A retrospective chart review was conducted to include all patients with nonsyndromic cleft lip and/or cleft palate who underwent Le Fort III rotation advancement of the midface from 1999 to 2011. Along with standard outcome measures, Amira imaging software was used to perform surface analysis on the last five consecutive patients in this series. RESULTS: Forty-three consecutive patients met inclusion criteria. Diagnoses included unilateral complete cleft lip and palate (n = 25) and bilateral complete cleft lip and palate (n = 18). Average distraction distance measured 10.1 mm at the level of the zygoma (range, 6 to 15 mm). Preoperative and 6-month postoperative sella, nasion, A point angles measured 76.3 and 81.8 degrees; whereas sella, nasion, B point angles measured 79.9 and 78.7 degrees, respectively. Preoperative and 6-month postoperative overjet measured -5.4 and 3.2 mm, whereas overbite measured 1.9 and 1.1 mm, respectively. Six patients (13 percent) developed pseudorelapse, with five patients going on to have subsequent Le Fort I advancement at an average of 7 years after distraction (range, 2 to 11 years). CONCLUSIONS: Le Fort III rotation advancement of the midface addresses severe midface deficiencies in select patients. Whereas older techniques target occlusal correction alone, extending osteotomies to the Le Fort III level allows occlusal correction along with improvements in malar and nasal projection required to achieve facial harmony in this group of patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Cortical plasticity induced by different degrees of peripheral nerve injuries: a rat functional magnetic resonance imaging study under 9.4 Tesla.

BACKGROUND: Major peripheral nerve injuries not only result in local deficits but may also cause distal atrophy of target muscles or permanent loss of sensation. Likewise, these injuries have been shown to instigate long-lasting central cortical reorganization. METHODS: Cortical plasticity changes induced after various types of major peripheral nerve injury using an electrical stimulation technique to the rat upper extremity and functional magnetic resonance imaging (fMRI) were examined. Studies were completed out immediately after injury (acute stage) and at two weeks (subacute stage) to evaluate time affect on plasticity. RESULTS: After right-side median nerve transection, cortical representation of activation of the right-side ulnar nerve expanded intra-hemispherically into the cortical region that had been occupied by the median nerve representation After unilateral transection of both median and ulnar nerves, cortical representation of activation of the radial nerve on the same side of the body also demonstrated intra-hemispheric expansion. However, simultaneous electrical stimulation of the contralateral uninjured median and ulnar nerves resulted in a representation that had expanded both intra- and inter-hemispherically into the cortical region previously occupied by the two transected nerve representations. CONCLUSIONS: After major peripheral nerve injury, an adjacent nerve, with similar function to the injured nerve, may become significantly over-activated in the cortex when stimulated. This results in intra-hemispheric cortical expansion as the only component of cortical plasticity. When all nerves responsible for a certain function are injured, the same nerves on the contralateral side of the body are affected and become significantly over-activated during a task. Both intra- and inter-hemispheric cortical expansion exist, while the latter dominates cortical plasticity.

Extramammary Paget's disease: a novel approach to treatment using a modification of peripheral Mohs micrographic surgery.

Extramammary Paget's disease is a rare intraepithelial adenocarcinoma typified histologically by the presence of Paget cells. Treatment has historically been surgical, with wide excision being the standard of care. However, due to clinically indeterminate margins and diffuse spread, local recurrence rates remain high. Mohs micrographic surgery has been proposed to improve the rate of local recurrence. Application of Mohs technique to treat extramammary Paget's disease can be difficult because of the large size of these lesions. Reported excisions either involved lengthy procedures or peripheral Mohs modification. The peripheral technique does not evaluate the depth of the central lesion, yet prognosis and lymph node involvement are directly related to the degree of vertical invasion. In this study, we discuss our experience with extramammary Paget's disease, along with a novel approach to treatment by using a modification of peripheral Mohs micrographic surgery that incorporates histologic analysis of the central specimen's depth.

Long-term vascular access ports as a means of sedative administration in a rodent fMRI survival model.

The purpose of this study is to develop a rodent functional magnetic resonance imaging (fMRI) survival model with the use of heparin-coated vascular access devices. Such a model would ease the administration of sedative agents, reduce the number of animals required in survival experiments and eliminate animal-to-animal variability seen in previous designs. Seven male Sprague-Dawley rats underwent surgical placement of an MRI-compatible vascular access port, followed by implantable electrode placement on the right median nerve. Functional MRI during nerve stimulation and resting-state functional connectivity MRI (fcMRI) were performed at times 0, 2, 4, 8 and 12 weeks postoperatively using a 9.4T scanner. Anesthesia was maintained using intravenous dexmedetomidine and reversed using atipamezole. There were no fatalities or infectious complications during this study. All vascular access ports remained patent. Blood oxygen level dependent (BOLD) activation by electrical stimulation of the median nerve using implanted electrodes was seen within the forelimb sensory region (S1FL) for all animals at all time points. The number of activated voxels decreased at time points 4 and 8 weeks, returning to a normal level at 12 weeks, which is attributed to scar tissue formation and resolution around the embedded electrode. The applications of this experiment extend far beyond the scope of peripheral nerve experimentation. These vascular access ports can be applied to any survival MRI study requiring repeated medication administration, intravenous contrast, or blood sampling.

Double stellate tongue reduction: a new method of treatment for macroglossia in patients with Beckwith-wiedemann syndrome.

BACKGROUND: Although multiple methods of tongue reduction have been described, recent literature suggests that the central reductions may be more favorable in patients with Beckwith-Wiedemann syndrome (BWS). In this case series, we review our experience with macroglossia associated with BWS, and we offer a new technique of central tongue reduction. METHODS: Between 1993 and 2007, a retrospective chart review was conducted to include all patients with a diagnosis of BWS who have undergone stellate or double stellate tongue reduction at the Children's Hospital of Wisconsin. RESULTS: A total of 7 patients met all inclusion criteria. All patients had good tongue mobility at 1-year follow-up. One patient required speech therapy for persistent articulation errors postoperatively. A total of 2 patients required secondary procedures for recurrent macroglossia. There were no complaints of abnormal taste or sensation. CONCLUSIONS: The stellate and double stellate tongue reductions provide effective treatment in macroglossia associated with BWS.

Refining the sensory and motor ratunculus of the rodent upper extremity: evaluation of the C7 nerve root using fMRI and direct nerve stimulation.

BACKGROUND: Since the 1980s, the C7 nerve root has gained clinical relevance as a donor nerve in severe brachial plexus root avulsion injuries. Despite success with the cross-chest C7 nerve transfer, inducing injury on an otherwise normal side hinders global acceptance. By sacrificing the C7 nerve root, a predictable pattern of transient sequelae is seen, including extensor weakness and index and middle finger anesthesia. The purpose of this study is to observe cortical activity during direct stimulation of the C7 nerve root using blood oxygen level dependent functional magnetic resonance imaging (fMRI) in a rat model. METHODS: A total of 12 male Sprague-Dawley rats, weighing 200-250 g, were used in this study. Following an acclimation period of 1 week, 12 rats underwent exposure and dissection of the brachial plexus. Seven rats underwent placement of an implantable electrode (AISI 304, Plastics1, Roanoke, VA, USA) on the C7 nerve root, while five rats underwent electrode placement on the radial nerve. All animals then underwent fMRI during direct nerve stimulation. Ten consecutive coronal images were obtained during nerve stimulation, using a 9.4-T small-animal MRI scanner. RESULTS: Cortical activation is seen within a very specific area of the primary sensory region of the forelimb during C7 nerve root stimulation. The cortical activation seen during radial nerve stimulation includes that seen during C7 stimulation but extends several slices caudally. CONCLUSIONS: The sensory representation of the C7 nerve root is seen in only a small area in the S1FL region compared to that seen in the terminal branches of the brachial plexus. However, this area shows a significant overlap with the S1FL area of activation seen during radial nerve stimulation. This makes sense as the C7 nerve root contributes some, but not all, sensory axons to the radial nerve. Mapping of the C7 cortical representation in the rat brain not only adds to the ongoing development of the motor and sensory ratunculus but also provides an important foundation to study subsequent C7 donor nerve models.