C# Definition:

[StructLayout(LayoutKind.Sequential)]

struct MIB_TCPROW_OWNER_PID {
    public TcpState state;
    public uint localAddr;
    public byte localPort1;
    public byte localPort2;
    public byte localPort3;
    public byte localPort4;
    public uint remoteAddr;
    public byte remotePort1;
    public byte remotePort2;
    public byte remotePort3;
    public byte remotePort4;
    public int owningPid;
}

VB Definition:

Structure MIB_TCPROW_OWNER_PID
    public TcpState state;
    public uint localAddr;
    public byte localPort1;
    public byte localPort2;
    public byte localPort3;
    public byte localPort4;
    public uint remoteAddr;
    public byte remotePort1;
    public byte remotePort2;
    public byte remotePort3;
    public byte remotePort4;
    public int owningPid;
End Structure

User-Defined Field Types:

None.

Notes:

This table entry is specifically returned by a call to GetExtendedTcpTable with the TableClass parameter set to a TCP_TABLE_OWNER_PID_* value from the TCP_TABLE_CLASS enumeration and the ulAf parameter set to AF_INET4.

Ports are broken up by bytes. (This is the same as the standard library does it). High order by is returned first.   Port 139 would be represented as  localPort1 =0, localPort2=139, localPort3=0, localPort4=0, where as 5800 would be localPort1=22, localPort2=168, etc...,   MSDN shows these as being DWORD.