Smita Sihag

Minimally Invasive Versus Open Esophagectomy for Esophageal Cancer: A Comparison of Early Surgical Outcomes From The Society of Thoracic Surgeons National Database

BACKGROUND Open esophagectomy results in significant morbidity and mortality. Minimally invasive esophagectomy (MIE) has become increasingly popular at specialized centers with the aim of improving perioperative outcomes. Numerous single-institution studies suggest MIE may offer lower short-term morbidity. The two approaches are compared using a large, multiinstitutional database. METHODS The Society of Thoracic Surgeons (STS) National Database (v2.081) was queried for all resections performed for esophageal cancer between 2008 and 2011 (n = 3,780). Minimally invasive approaches included both transhiatal (n = 214) and Ivor Lewis (n = 600), and these were compared directly with open transhiatal (n = 1,065) and Ivor Lewis (n = 1,291) procedures, respectively. Thirty-day outcomes were examined using nonparametric statistical testing. RESULTS Both open and MIE groups were similar in terms of preoperative risk factors. Morbidity and all-cause mortality were equivalent at 62.2% and 3.8%. MIE was associated with longer median procedure times (443.0 versus 312.0 minutes; p < 0.001), but a shorter median length of hospital stay (9.0 versus 10.0 days; p < 0.001). Patients who underwent MIE had higher rates of reoperation (9.9% versus 4.4%; p < 0.001) and empyema (4.1% versus 1.8%; p < 0.001). Open technique led to an increased rate of wound infections (6.3% versus 2.3%; p < 0.001), postoperative transfusion (18.7% versus 14.1%; p = 0.002), and ileus (4.5% versus 2.2%; p = 0.002). Propensity score-matched analysis confirmed these findings. High- and low-volume centers had similar outcomes. CONCLUSIONS Early results from the STS National Database indicate that MIE is safe, with comparable rates of morbidity and mortality as open technique. Longer procedure times and a higher rate of reoperation following MIE may reflect a learning curve.

Comparison of perioperative outcomes following open versus minimally invasive Ivor Lewis oesophagectomy at a single, high-volume centre

OBJECTIVES With the increasing popularity of minimally invasive oesophageal resections, equivalence, if not superiority, to open techniques must be demonstrated. Here we compare our open and minimally invasive Ivor Lewis oesophagectomy (MIE) experience. METHODS A prospective database of all oesophagectomies performed at Massachusetts General Hospital in Boston, MA between November 2007 and January 2011 was analysed. A total of 38 MIE and 76 open Ivor Lewis (OIE) oesophagectomies were performed for oesophageal carcinoma. Sixty-day surgical, oncological and postoperative outcomes were examined between the two groups. RESULTS Groups had similar demographics in terms of age, gender, tumour histology, clinical stage, preoperative comorbidities and neoadjuvant therapy. No difference was found with respect to adequacy of oncological resections. The median number of lymph nodes retrieved (OIE: 21, inter-quartile range (IQR): (16, 27) versus MIE: 19, IQR: (15, 28)), resection margins (OIE: 6.6% positive versus MIE: no positive margins) and 60-day mortality (OIE: 2.6% versus MIE: no deaths) were comparable. However, rates of pulmonary complications were significantly lower in the MIE group (OIE: 43.4 versus MIE: 2.6%, P < 0.001). Additionally, the median length of ICU and hospital stay, intraoperative blood loss and amount of intravenous fluids infused intraoperatively were also significantly decreased with MIE, while median operative times and the requirement for intraoperative blood transfusion were not significantly different between the two groups. Multivariate logistic regression analysis identified MIE as the only variable associated with a significant reduction in the rate of pulmonary complications in our study, while pre-existing pulmonary comborbidity was associated with an increased risk of pulmonary complications. CONCLUSIONS Open and MIE appear equivalent with regard to early oncological outcomes. A minimally invasive approach, however, appears to lead to a significant reduction in the rate of postoperative pulmonary complications. Length of ICU and hospital stay, as well as intraoperative blood loss and intravenous fluid requirements are also reduced in the setting of MIE. Long-term survival data will need to be followed closely. A large, multi-centred, randomized, controlled trial is warranted to confirm these results.

Induction of Cardiac Allograft Tolerance Across a Full MHC Barrier in Miniature Swine by Donor Kidney Cotransplantation

We have previously shown that tolerance of kidney allografts across a full major histocompatibility complex (MHC) barrier can be induced in miniature swine by a 12‐day course of high‐dose tacrolimus. However, that treatment did not prolong survival of heart allografts across the same barrier. We have now tested the effect of cotransplanting an allogeneic heart and kidney from the same MHC‐mismatched donor using the same treatment regimen. Heart allografts (n = 3) or heart plus kidney allografts (n = 5) were transplanted into MHC‐mismatched recipients treated with high‐dose tacrolimus for 12 days. As expected, all isolated heart allografts rejected by postoperative day 40. In contrast, heart and kidney allografts survived for >200 days with no evidence of rejection on serial cardiac biopsies. Heart/kidney recipients lost donor‐specific responsiveness in cell‐mediated lympholysis and mixed‐lymphocyte reaction assays, were free of alloantibody and exhibited prolonged survival of donor, but not third‐party skin grafts. Late (>100 days) removal of the kidney allografts did not cause acute rejection of the heart allografts (n = 2) and did not abrogate donor‐specific unresponsiveness in vitro. While kidney‐induced cardiac allograft tolerance (KICAT) has previously been demonstrated across a Class I disparity, these data demonstrate that this phenomenon can also be observed across the more clinically relevant full MHC mismatch. Elucidating the renal element(s) responsible for KICAT could provide mechanistic information relevant to the induction of tolerance in recipients of isolated heart allografts as well as other tolerance‐resistant organs.

Prevention and Management of Complications Following Tracheal Resection.

Careful patient selection and preparation are paramount to optimize outcomes following tracheal resection. Risk factors for postoperative anastomotic complications include age less than 17 years, reoperation, laryngeal involvement, diabetes, increased length of resection, and need for preoperative tracheostomy. Major complications involve the anastomosis and are associated with an increased risk of mortality. Complications range from granulation tissue formation to stricture to separation, and successful management typically requires reoperation, T-tube stenting, or tracheostomy. Other complications to consider include vocal cord edema, recurrent laryngeal nerve injury, esophageal injury, wound infection, swallowing dysfunction, aspiration pneumonia, and fistula to the esophagus or innominate artery.

Recipient-matching of Passenger Leukocytes Prolongs Survival of Donor Lung Allografts in Miniature Swine

Background Allograft rejection continues to be a vexing problem in clinical lung transplantation, and the role played by passenger leukocytes in the rejection or acceptance of an organ is unclear. We tested whether recipient-matching of donor graft passenger leukocytes would impact graft survival in a preclinical model of orthotopic left lung transplantation. Methods In the experimental group (group 1), donor lungs were obtained from chimeric swine, in which the passenger leukocytes (but not the parenchyma) were major histocompatibility complex–matched to the recipients (n = 3). In the control group (group 2), both the donor parenchyma and the passenger leukocytes were major histocompatibility complex–mismatched to the recipients (n = 3). Results Lungs harvested from swine previously rendered chimeric by hematopoietic stem cell transplantation using recipient-type cells showed a high degree of passenger leukocyte chimerism by immunohistochemistry and flow cytometry. The chimeric lungs containing passenger leukocytes matched to the lung recipient (group 1) survived on average 107 days (range, 80-156). Control lung allografts (group 2) survived on average 45 days (range, 29-64; P < 0.05). Conclusions Our data indicate that recipient-matching of passenger leukocytes significantly prolongs lung allograft survival.

Natural IgM Blockade Limits Infarct Expansion and Left Ventricular Dysfunction in a Swine Myocardial Infarct Model

Background—Acute coronary syndrome is the leading cause of mortality worldwide. However, treatment of acute coronary occlusion inevitably results in ischemia-reperfusion injury. Circulating natural IgM has been shown to play a significant role in mouse models of ischemia-reperfusion injury. A highly conserved self-antigen, nonmuscle myosin heavy chain II, has been identified as a target of pathogenic IgM. We hypothesized that a monoclonal antibody (m21G6) directed against nonmuscle myosin heavy chain II may inhibit IgM binding and reduce injury in a preclinical model of myocardial infarction. Thus, our objective was to evaluate the efficacy of intravenous m21G6 treatment in limiting infarct expansion, troponin release, and left ventricular dysfunction in a swine myocardial infarction model. Methods and Results—Massachusetts General Hospital miniature swine underwent occlusion of the midleft anterior descending coronary artery for 60 minutes, followed by 1 hour, 5-day, or 21-day reperfusion. Specificity and localization of m21G6 to injured myocardium were confirmed using fluorescently labeled m21G6. Treatment with m21G6 before reperfusion resulted in a 49% reduction in infarct size (P<0.005) and a 61% reduction in troponin-T levels (P<0.05) in comparison with saline controls at 5-day reperfusion. Furthermore, m21G6-treated animals recovered 85.4% of their baseline left ventricular function as measured by 2-dimensional transthoracic echocardiography in contrast to 67.1% in controls at 21-day reperfusion (P<0.05). Conclusions—Treatment with m21G6 significantly reduced infarct size and troponin-T release, and led to marked preservation of cardiac function in our study. Overall, these findings suggest that pathogenic IgM blockade represents a valid therapeutic strategy in mitigating myocardial ischemia-reperfusion injury.

Lymph Node Dissection and Pulmonary Metastasectomy

Unexpected lymph node involvement is observed in approximately 20% of all patients undergoing pulmonary metastasectomy. Lymph node metastasis is often associated with decreased survival in patients with pulmonary metastases. The incidence of lymph node involvement is related to a variety of patient and tumor variables. This article reviews the indications and role for lymph node assessment at pulmonary metastasectomy.

Management of Complicated and Strangulated Hiatal Hernias

Large, complicated hiatal hernias are relatively rare, typically affecting the elderly. Type II–IV hiatal hernias are also known as paraesophageal hernias, and the most prevalent is a type III hernia where the gastroesophageal junction migrates cephalad into the chest, frequently accompanied by a portion of the stomach adjacent to the esophagus, as a consequence of laxity in the phrenoesophageal attachments. Approximately half of all paraesophageal hernias are symptomatic, and most commonly, symptoms in the acute presentation are related to volvulus and obstruction and constitute nausea, postprandial chest or epigastric pain, and bloating. Other acute manifestations of paraesophageal hernia include strangulation, perforation, and bleeding. Diagnosis primarily relies on abdominal computed tomography and upper gastrointestinal series. The risk of developing acute gastric volvulus requiring emergency surgery is estimated at less than 2 % per year. Mortality following emergency surgery has historically been reported to be as high as 56 %, though currently in the laparoscopic era, it has decreased significantly to a rate of 5–20 %. All symptomatic paraesophageal hernias should be repaired, in accordance with the guidelines, and the standard approach is laparoscopic even in urgent cases. The principles of laparoscopic repair of large paraesophageal hernias in order to minimize recurrence are (1) reduction of the hernia with at least 2–3 cm of intra-abdominal esophageal length, (2) complete excision of the hernia sac, and (3) tension-free closure of the hiatus. Fixation of the stomach within the abdomen is traditionally performed via fundoplication, but gastropexy or gastrostomy tube placement is acceptable in certain instances.