Bulging upper abdomen after full tummy tuck 6 weeks post op. Is this normal? (photos)

Agree with dehiscence muscle repair in upper abdomen. Allow 3 months healing to see if the internal scarring will improve. Othjerwise revise operation might be the only answer... Sorry. 

I am sorry to hear about your concerns after tummy tuck surgery.
As always, it is best to be seen in person ( by your plastic surgeon) for precise diagnosis and treatment.Generally speaking, abdominal wall "swelling" after tummy tuck may be related to:
1. Swelling in the soft tissues. This may take several months to resolve and may worsen with increased activity or at the end of the day. Patience is required to allow for resolution of the swelling. The swelling occurs because of the interruption of venous and lymphatic channels that occurs during the tummy tuck operation.
2. Fluid accumulation in the space between the skin and the abdominal wall muscle. this may consist of blood ( hematoma) or serum (seroma). This fluid accumulation can generally be diagnosed by physical examination ( occasionally ultrasound may be helpful). Treatment consists of aspiration; several episodes of aspiration may be necessary.
3. Separation of the abdominal wall muscle repair may lead to a swelling/bulge appearance. This may be diagnosed on physical examination with your surgeon examining you in different bodily positions. One of the steps of a tummy tuck procedure involves reapproximation (plication) of the rectus muscles. These muscles have spread apart during pregnancy and/or weight gain. Bringing them together again in the midline helps to “tighten” the abdominal wall as well as to narrow the waistline.
4. Residual adipose tissue may be confused for swelling. Again this is most easily diagnosed by physical examination. Additional liposuction surgery maybe necessary to improve the results of surgery.
Generally, it takes many months for swelling to resolve after tummy tuck surgery and it may take up to one year (or greater) a complete skin redraping to occur.
I hope this, and your second opinion consultation, helps. 

Since your imaging study excluded seroma, failure of the muscle repair is the likely cause. Hernia is also a possibility, but that would have been seen on the study.An in person evaluation, which it seems is in the cards is the best next step. A repair can be considered, but it would be best to hold off until 3 to 6 months after surgery, or longer. An overlay of prosthetic mesh may be a consideration since the first closure failed. All the best. 

If ultrasound ruled out fluid, then it is most likely a muscle dehiscence/seoaration issue. This would be rare. Far more likely would have been a fluid issue. If this is what it is, best is to heal for 4 months and lest the tissues resolve their swelling and go back in and retighten the muscles perhaps with some additional support materials.